CN116420415A

CN116420415A - User equipment, base station and public beam determining method

Info

Publication number: CN116420415A
Application number: CN202080106294.XA
Authority: CN
Inventors: 田茂新; 生嘉; 黎添
Original assignee: JRD Communication Shenzhen Ltd
Current assignee: JRD Communication Shenzhen Ltd
Priority date: 2020-10-16
Filing date: 2020-10-16
Publication date: 2023-07-11
Also published as: WO2022077485A1

Abstract

A User Equipment (UE), a base station, and a common beam determining method are provided. A method of UE common beam determination includes the UE determining one or more transmission configuration indication (transmission configuration indication, TCI) states from a base station, wherein the one or more TCI states include one or more reference signals (reference signals, RS), the UE determining one or more beams from the base station, wherein the one or more beams are used for multi-beam operation, the UE identifying one or more common beams from the one or more beams according to the one or more RSs, and the UE using the one or more common beams for Downlink (DL) reception and Uplink (UL) transmission in the multi-beam operation. This defines a unified common beam indication for DL and UL in multi-beam operation.

Description

User equipment, base station and public beam determining method

Technical Field

The present invention relates to the field of wireless communication systems operating in multiple-input multiple-output (MIMO) systems, and more particularly, to a method of User Equipment (UE), base station and common beam determination, which may enhance Downlink (DL) and Uplink (UL) data in multi-beam transmission and control of transmission/reception common beam design.

Background

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These wireless communication systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems and fifth generation (5G) systems, which may be referred to as New Radio (NR) systems. Such systems may employ techniques such as Code Division Multiple Access (CDMA), time Division Multiple Access (TDMA), frequency Division Multiple Access (FDMA), orthogonal Frequency Division Multiple Access (OFDMA), or discrete fourier transform spread OFDM (DFT-S-OFDM). A wireless multiple-access communication system may include multiple base stations or network access nodes, each supporting communication for multiple communication devices, which may be otherwise referred to as User Equipment (UE), simultaneously.

The wireless communication network may include base stations that may support communication for UEs. The UE may communicate with the base station via a Downlink (DL) and an Uplink (UL). DL refers to the base station to UE communication link and UL refers to the UE to base station communication link.

Multiple Input Multiple Output (MIMO) is an effective method of enhancing radio link capacity due to multiplexing of transmit and receive antennas. MIMO refers to a practical technique for simultaneously transmitting and receiving multiple data signals on the same radio channel, which greatly improves the performance of spectral efficiency. However, DL and UL beam indication mechanisms in multi-beam transmission operating in MIMO systems remain a pending problem.

Accordingly, there is a need for a User Equipment (UE), a base station, and a common beam determining method that can solve the problems in the prior art, define a uniform common beam indication for data and control transmission/reception of DL and UL in multi-beam operation, enhance the common beam design for DL and UL data and control transmission/reception in multi-beam operation, provide good communication performance, and/or provide high reliability.

Disclosure of Invention

An object of the present invention is to propose a User Equipment (UE), a base station and a common beam determining method, which can solve the problems in the prior art, define a uniform common beam indication for data and control transmission/reception of DL and UL in multi-beam operation, enhance the common beam design for DL and UL data and control transmission/reception in multi-beam operation, provide good communication performance, and/or provide high reliability.

In a first aspect of the present invention, a method for determining a public beam by a user equipment UE is characterized by comprising: the UE determining that one or more transmission configurations from a base station indicate a TCI state, wherein the one or more TCI states include one or more reference signals, RSs; the UE determining one or more beams from the base station, wherein the one or more beams are for multi-beam operation; the UE identifies one or more public beams from the one or more beams according to the one or more RSs; and the UE using the one or more common beams for downlink DL reception and uplink UL transmission in the multi-beam operation.

In one embodiment of the invention, the one or more common beams are indicated according to the one or more RSs associated with the one or more beams.

In one embodiment of the invention, the TCI state of the base station configuration is only one.

In one embodiment of the invention, when there is only one RS in one TCI state, the RS is associated with the common beam for both the DL reception and/or the UL transmission in the multi-beam operation.

In one embodiment of the present invention, the RS includes DL RS and/or UL RS.

In one embodiment of the present invention, the DL RS includes channel state information CSI RS.

In one embodiment of the present invention, the UL RS includes a sounding reference signal SRS.

In an embodiment of the invention, the common beam is indicated using radio resource control, RRC, signaling and medium access control, MAC, control element, CE, signaling.

In one embodiment of the present invention, the one TCI state is activated by MAC CE signaling, and a downlink control information DCI field is used to indicate a beam in one TCL state.

In one embodiment of the invention, when the indication beam in the one TCI state is not the common beam, and if there are other common beams associated with the RS in the TCI state, the UE performs the DL reception and the UL transmission in the multi-beam operation using the common beam having the lowest index in the TCI state.

In one embodiment of the invention, when the UE is configured with the beam associated with the RS of the TCI state, the method further comprises the UE determining a mapping between the beam and the RS.

In one embodiment of the present invention, the UE identifying the one or more common beams from the one or more beams according to the one or more RSs includes: the UE identifies the one or more common beams from the beams according to the mapping of the beams to the RSs.

In one embodiment of the invention, the RS includes parameters including at least one of: a number of bits; or a time slot of an UL signal received by the base station.

In one embodiment of the present invention, the UE determines a mapping between the beam and the RS through system information.

In one embodiment of the present invention, the UE identifies the one or more common beams from the beams according to the mapping of the beams and the RSs, including: the UE performs beam measurement on the beam according to the mapping of the beam and the RS; the UE reports the beam measurement to the base station; the UE receives a first indication of the one or more common beams from the base station, wherein the first indication of the one or more common beams includes a first selection of the one or more common beams by the base station according to the beam measurements.

In one embodiment of the present invention, the UE identifies the one or more common beams from the beams according to the mapping of the beams and the RSs, including: the UE performing UL beam scanning; the UE sends the UL RS configured in the TCI state to the base station; and the UE receiving a second indication of the one or more common beams from the base station, wherein the second indication of the one or more common beams includes a second selection of the one or more common beams by the base station according to the UL RS.

In one embodiment of the present invention, the one or more common beams depend on the UL RS associated, wherein the UL RS is a signal most recently received by the base station.

In one embodiment of the invention, the TCI state is activated by MAC CE signaling, and the application downlink control information DCI field indicates that the one or more beams are in the one or more TCI states for a scheduling time.

In one embodiment of the invention, when one or more indicated beams in the one or more TCI states within the scheduled time are not the one or more common beams, the UE uses the most recently indicated common beam for the DL reception and the UL transmission prior to the scheduled time in the multi-beam operation.

In one embodiment of the invention, the method is performed in a joint common beam indication mode, a separate common beam indication mode, a hybrid common beam indication mode or a default common beam indication mode.

In one embodiment of the invention, when the method is performed in the joint common beam indication mode, the UE uses the same common beam for the DL reception and the UL transmission in the multi-beam operation.

In one embodiment of the invention, for the joint co-beam indication scheme, both the DL reception and the UL transmission are indicated by only one common beam, and when only one RS is in a single TCI state, the RS is associated with the common beam for both the DL reception and the UL transmission.

In one embodiment of the present invention, the RS is the DL RS or the UL RS.

In one embodiment of the invention, for the joint common beam indication scheme, a combination of K beams associated with a flag is used to identify the common beam, where K is greater than 1.

In one embodiment of the present invention, if several of the K beams are the common beam, the common beam is determined with a flag value corresponding to each beam.

In one embodiment of the present invention, if the DL RS provides the common beam, the base station selects a beam associated with the number of bits in the flag through the reporting CSI from the UE, if the UL RS provides the common beam, the base station selects a beam associated with the number of bits in the flag through the SRS from the UE, the selected beam depending on an associated uplink signal received at the base station in a most recently received signal including the reporting CSI or the SRS, and a combination of K beams and a flag is used to identify whether the indicated beam is the common beam.

In one embodiment of the present invention, for the joint common beam indication mode, each beam is used for one time slot unit, the base station selects the beam by the most recently received signal including reporting CSI or SRS, each signal received by the base station corresponds to one time slot, and whether the selected beam is the common beam is identified by the correspondence between the time slot and the beam.

In one embodiment of the invention, when the method is performed in the split common beam indication mode, the UE applies independent common beams for the DL reception and the UL transmission, respectively, in the multi-beam operation.

In one embodiment of the present invention, wherein the one or more RSs of M TCIs provide quasi-co-located QCL hypotheses for the DL reception, the one or more RSs of N TCIs provide spatial filters for the UL transmission, and one or more candidate common beams for the DL reception and the UL transmission are contained in the M TCIs and the N TCIs, respectively, where M is greater than or equal to 1 and N is greater than or equal to 1.

In one embodiment of the invention, for the DL reception or the UL transmission, when there is only one TCI state, the TCL state includes only one RS to provide a QCL assumption for the DL reception or the spatial filter for the UL transmission, the beam associated with the RS being the common beam for the DL reception or the UL transmission in the multi-beam operation.

In one embodiment of the present invention, when the RS is associated with a plurality of K DL beams and L UL beams contained in the TCI state, the RS is configured to indicate whether k×l beam pairs include the one or more common beams.

In one embodiment of the invention, when the method is performed in the split common beam indication mode and when only one TCI state contains only one RS providing a reference for QCL or the spatial filter, the beam associated with the RS is the common beam for the DL reception or the UL transmission.

In one embodiment of the present invention, when the method is performed in the separate common beam indication mode and when the base station performs beam scanning, the UE performs beam measurement, and after measuring the beam, the UE transmits the UL RS to the base station at a slot position associated with the measured beam, and the base station measures the UL RS and selects an optimal UL beam to obtain a beam pair.

In one embodiment of the present invention, when the method is performed in the split common beam indication mode and there is only one TCI state, both DL beams associated with DL RSs and UL beams associated with UL RSs are configured in the TCI state.

In one embodiment of the invention, when the method is performed in the split common beam indication mode and only one TCI state, and if neither the indicated DL beam nor the indicated UL beam of the indicated beam pair is a DL common beam and a UL common beam, the UE uses the common beam with the lowest beam pair index in the TCI state for the DL reception and the UL transmission in the multi-beam operation.

In one embodiment of the invention, when the method is performed in the split common beam indication mode and only one TCI state, if an indicated beam pair is not the common beam but an indicated DL beam or an indicated UL beam of the indicated beam pair is a DL common beam or an UL common beam, the UE uses the common beam with the lowest beam pair index for DL and UL indications in TCI state, wherein the lowest beam pair includes the DL or UL common beam related to the indicated common beam pair.

In one embodiment of the invention, when the method is performed in the split common beam indication mode, when the UE is configured with a plurality of TCI states, when the common beam does not exist in an indicated TCI state, and if neither an indicated DL beam nor an indicated UL beam of the indicated beam pair is a DL common beam nor an UL common beam, the UE performs the DL reception and the UL transmission using the latest indicated common beam before a scheduling time.

In one embodiment of the present invention, when the method is performed in the split common beam indication mode, when the UE configures a plurality of TCI states, when the common beam does not exist in an indicated TCI state, and if a DL beam or an UL beam of an indicated common beam pair is the common beam, the UE performs the DL reception and the UL transmission using a latest indicated common beam before a scheduling time, wherein the indicated common beam includes the DL or UL common beam related to the indicated common beam pair within the scheduling time.

In one embodiment of the invention, when the method is performed in the hybrid common beam indication mode, the UE uses a first type of common beam configured for the DL reception and the UL transmission in the multi-beam operation and a second type of common beam configured for only the DL reception or the UL transmission in the multi-beam operation.

In one embodiment of the present invention, one or more RSs configured in one or more TCLs provide the first type of common beam and the second type of common beam.

In one embodiment of the present invention, when the RS is associated with a plurality of K DL beams, L UL beams, S beams are applied to the DL reception and the UL transmission included in the TCI state, the RS is configured to indicate whether K times L plus S beam pairs include one or more common beams.

In one embodiment of the invention, the first type of common beam and the second type of common beam have different priorities.

In one embodiment of the invention, the first type of common beam has a higher priority than the second type of common beam.

In one embodiment of the present invention, when the common beam in the TCI state does not exist, the first type common beam and the second type common beam configured with higher priority included in the TCI state indicated by the latest scheduling time are regarded as the common beam.

In one embodiment of the present invention, the base station configures a time window for the UE for distinguishing whether the common beam or the common beam pair is valid.

In one embodiment of the invention, if there is not only the first type of common beam within a window time, the UE uses the common beam with the lowest index in the TCI state for the DL reception and the UL transmission in the multi-beam operation; and/or if only the second kind of common beam is included within the window time, the UE uses the common beam with the lowest beam pair index for the DL reception and the UL transmission in the multi-beam operation in the TCI state.

In one embodiment of the present invention, when the method is performed in the hybrid common beam indication mode, K times L beam pairs are obtained by combining K DL beams associated with a plurality of DL RSs and L UL beams associated with a plurality of UL RSs, and K times L plus S beams/pairs are available in total for the DL reception and the UL transmission.

In one embodiment of the invention, when the method is performed in the hybrid common beam indication mode, if there is one selected beam, which indexes from the first beam to the s-th beam, the UE measures the beam with the RS, providing only the common beam for the DL reception or the UL transmission; and/or if there is a selected beam having an index from a first beam pair to K times an L-th beam pair, the UE uses the RS to measure the beam, providing the common beam for the DL reception and the UL transmission.

In one embodiment of the present invention, when the method is performed in the default common beam indication mode, the UE uses one or more default common beams as the one or more common beams when DL and UL default beams are aligned.

In one embodiment of the invention, the one or more default common beams comprise the latest common beam with the lowest index contained in one of the scheduled times.

In a second aspect of the present invention, a method for a base station to perform common beam determination includes: the base station configures one or more Transmission Configuration Indication (TCI) states to User Equipment (UE), wherein the one or more TCI states comprise one or more Reference Signals (RS); the base station configures one or more beams to the UE, wherein the one or more beams are for multi-beam operation; the base station identifying one or more common beams from the one or more beams according to the one or more RSs; and the base station using the one or more common beams for downlink DL reception and uplink UL transmission in the multi-beam operation.

In one embodiment of the present invention, the RS includes DL RS and/or UL RS.

In one embodiment of the invention, the common beam is indicated using radio resource control, RRC, signaling and medium access control, MAC, control element, CE, signaling.

In one embodiment of the invention, when the method is performed in a joint common beam indication mode, the UE uses the same common beam for the DL reception and the UL transmission in the multi-beam operation.

In one embodiment of the present invention, the base station identifying the one or more common beams from the one or more beams according to the one or more RSs includes: the base station identifies the one or more common beams from the beams according to the mapping of the beams to the RSs.

In one embodiment of the present invention, the base station determines a mapping between the beam and the RS through system information.

In one embodiment of the present invention, the base station identifies the one or more common beams from the beams according to the mapping of the beams and the RS, including: the base station receives beam measurement of the beam according to the mapping between the beam and the RS sent by the UE; and the base station sending a first indication of the one or more common beams to the UE, wherein the first indication of the one or more common beams comprises a first selection of the one or more common beams by the base station according to the beam measurements.

In one embodiment of the present invention, the base station identifies the one or more common beams from the beams according to the mapping of the beams and the RS, including: the base station receiving a UL RS configured in the TCI state from the UE; the base station measures UL RS from the UE; and the base station transmitting a second indication of the one or more common beams to the UE, wherein the second indication of the one or more common beams includes a second selection of the one or more common beams by the base station according to the UL RS.

In one embodiment of the present invention, the RS is the DL RS or the UL RS.

In a third aspect of the invention, a user equipment, UE, for common beam determination comprises a memory, a transceiver, and a processor coupled to the memory and the transceiver. The processor is configured to determine one or more transmission configuration indications, TCI, states from the base station, wherein the one or more TCI states comprise one or more reference signals, RSs; determining one or more beams from the base station, wherein the one or more beams are for multi-beam operation; identifying one or more common beams from the one or more beams according to the one or more RSs; and using the one or more common beams for downlink DL reception and uplink UL transmission in the multi-beam operation.

In one embodiment of the invention, the processor is configured to perform the above-described method.

In a fourth aspect of the invention, a base station for common beam determination includes a memory, a transceiver, and a processor coupled to the memory and the transceiver. The processor is configured to configure one or more transmission configuration indications, TCI, states to the user equipment, UE, wherein the one or more TCI states comprise one or more reference signals, RSs; configuring one or more beams to the UE, wherein the one or more beams are for multi-beam operation; identifying one or more common beams from the one or more beams according to the one or more RSs; and using the one or more common beams for downlink DL reception and uplink UL transmission in the multi-beam operation.

In a fifth aspect of the invention, a non-transitory machine-readable storage medium having instructions stored thereon, which when executed by a computer, cause the computer to perform the above-described method.

In a sixth aspect of the invention, a chip comprises a processor configured to invoke and run a computer program stored in a memory to cause a device on which the chip is mounted to perform the above method.

In a seventh aspect of the present invention, a computer-readable storage medium stores a computer program, wherein the computer program causes a computer to execute the above-described method.

In an eighth aspect of the invention, a computer program product comprising a computer program, wherein the computer program causes a computer to perform the above method.

In a ninth aspect of the present invention, a computer program causes a computer to execute the above method.

Drawings

In order to further explain the technical solution of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced. It is apparent that the following drawings are merely some embodiments of the present invention. Other figures may be made by anyone skilled in the art without the inventive effort based on the following figures.

Fig. 1 is a schematic diagram of beam pointing in multiple-input multiple-output (MIMO) multi-beam transmission.

Fig. 2 is a block diagram of one or more User Equipments (UEs) and a base station (e.g., a gNB) communicating in a communication network system in accordance with an embodiment of the invention.

Fig. 3 is a flowchart of a method of common beam determination performed by a User Equipment (UE) according to an embodiment of the present invention.

Fig. 4 is a flow chart of a method of common beam determination performed by a base station according to an embodiment of the present invention.

Fig. 5 is a schematic diagram of an example of common beam determination when there is no common beam in a Transmission Configuration Indication (TCI) state according to an embodiment of the present invention.

Fig. 6 is a schematic diagram illustrating a common beam judgment example when there is no common beam in the TCI state according to an embodiment of the present invention.

Fig. 7 is a schematic diagram of an example of common beam determination when there is no common beam in the TCI state according to an embodiment of the present invention.

Fig. 8 is a block diagram of a system for wireless communication according to an embodiment of the present invention.

Detailed Description

Technical matters, structural features, achieved objects and effects of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In particular, the terminology used in the embodiments of the invention is for the purpose of describing the embodiments of the invention only and is not intended to be limiting of the invention.

Multi-beam operation in multiple-input multiple-output (MIMO):

one goal of beam management enhancement is primarily to reduce delay and overhead, and beam management may include three artifacts, namely beam measurement, beam reporting, and beam pointing. First, a base station, such as a gNB, is expected to scan multiple candidate beams for further management and transmit the candidate beams to a User Equipment (UE), which measures the candidate beams according to some performance criteria. Then, after the UE performs the beam measurements, the UE reports the beam measurements meeting the performance criteria to the gNB for further implementation. Finally, the gNB selects the best beam to indicate transmission of the Physical Downlink Shared Channel (PDSCH).

Fig. 1 illustrates beam pointing in multi-beam transmission in multiple-input multiple-output (MIMO). Fig. 1 illustrates establishing a beam link between a base station, such as a gNB, and a UE to enhance beam pointing. In current technology such as relay-15 New Radio (NR), dynamic beam indication of PDSCH is aimed at reducing delay and overhead, which is based on Transmission Configuration Indication (TCI) status associated with downlink reference signal (DL-RS), i.e., synchronization Signal Block (SSB) and channel state information-RS (CSI-RS). The beam indication of PDSCH is dynamically triggered by Downlink Control Information (DCI) carried on a Physical Downlink Control Channel (PDCCH), and the UE applies the indicated beam and switches the Receive (RX) beam after successfully decoding the DCI format. Further, in relay-15, NR may provide a spatial quasi co-location (QCL) relationship between DL-RS and demodulation reference signal (DM-RS) ports of PDSCH by supporting beam indication of PDSCH transmission using a 3-bit TCI field in the scheduling DCI. Specifically, the gNB configures a pool of TCI states in higher layer parameters (e.g., PDSCH-Config), which are associated with a plurality of candidate beams through Radio Resource Control (RRC). Then, the gNB activates the candidate TCI state through Medium Access Control (MAC) Control Element (CE) signaling to map the candidate TCI state to a code point of the DCI field. Finally, gNB indicates a TCI state of the DM-RS port of PDSCH through DCI signaling.

Fig. 1 also illustrates that the UE can only apply the indicated beam after decoding the scheduling DCI and applying Rx beam switching. Thus, the UE needs to be given enough time to decode the PDCCH and a time offset is required that is equal to or greater than a predefined threshold, e.g., timeduration forqcl, where the threshold is based on the reported UE capabilities. Further, in Relay-15/16, higher layer parameters, such as tci-PresentInDCI/tci-PresentInDCI-Format1_2, are set to "enabled" for CORESET scheduling PDSCH. For DL beam indication, if a TCI field is present in the DCI, a time offset between reception of the DL DCI and the corresponding PDSCH is equal to or greater than a predefined threshold, e.g., the DM-RS of timeDurationForQCL, PDSCH QCL with the DL-RS in the indicated TCI state. Otherwise, it is natural to use the predefined QCL assumption of PDSCH, i.e. the default beam. When TCI exists but the time offset between the reception of DL DCI and the corresponding PDSCH is less than a predefined threshold, e.g., timeduration forqcl, the UE assumes the QCL assumption of the lowest controllably resource id in the latest time slot in which one or more CORESET within the active bandwidth part (BWP) of the serving cell are located. In some cases, the TCI field is not always present in the DCI, and if the TCI field is not present in the DCI, the QCL assumption of the PDSCH follows CORESET transmitted with the PDCCH.

In release 15, the spatial relationship information is configured by higher layer parameters, such as the spatialRelationInfo for Uplink (UL) beam indication, where the spatial relationship information provides the RS from which the UE forms a UL Transmission (TX) beam for the target signal for which the spatial relationship information is configured. For the Physical Uplink Control Channel (PUCCH) and Sounding Reference Signal (SRS), the spatial relationship information may provide a direct spatial assumption, while for the physical uplink channel (PUSCH), the UE acquires the spatial relationship information indirectly from PUCCH (PUSCH scheduled using DCI format 0_0) or SRS resources. In release 15/16, however, DL and UL beam indication mechanisms are separately designed, and there may be some problems such as delay and signaling overhead since two sets of RRC and MAC CE signaling are required to configure and indicate the beams of PDSCH and PUSCH.

In the current technology, the PDSCH is investigated for scheduling by DCI format of PDCCH transmitted on CORESET, whereas for UL indication, SRS and PUCCH beam indication can be directly obtained through spatlrelationinfo and PUCCH-spatlrelationinfo, respectively. Unlike SRS and PUCCH, PUSCH beams are indicated by a Scheduling Request Indicator (SRI) in DCI. In release 15/16, DL and UL beams are indicated, respectively, which means that the gNB uses different signaling configurations TCI and spatialreactioninfo. Unified TCI frames are introduced to eliminate large signaling overhead. Furthermore, according to the future work item of relay-17, due to the limitation of the Radio Frequency (RF) analog beam control component, beam limitation enhancement of DL reception and UL transmission is enhanced at the same time, and it is difficult for the UE to receive and transmit signals using different beams for different physical channels. Thus, in some embodiments of the present invention, it is beneficial to design a common beam for DL and UL beam indications.

As with release 15/16, default beam support PDCCH, PDSCH, PUCCH, PUSCH and SRS, etc. When TCI-presentingii is absent or the scheduling offset is less than the threshold timeduration forqcl, the default beam is the QCL assumption of the TCI state or the lowest control resource estid in the latest slot monitored by the UE. When the UE is provided with enabledefaultstreamplforpusch 0_0, enabledefaultstreamplforsrs, or enabledefaultstreamplforpucch, the default beam is the QCL assumption of CORESET with the lowest controllable resource estid. As can be seen from the above, multiple DL and UL channels may apply a single default beam indicated by the gNB to reduce the signaling overhead of the beam indication. However, in Release-15/16, the default beam design is complex and not applicable in all cases, because the RSs of the DL and UL default beams are not always aligned, which may cause ambiguity to the implementation of the common beam by the UE.

Some embodiments of the invention propose methods regarding a unified TCI framework for DL and UL beam indication. Some embodiments of the invention provide a unified common beam design for DL reception and UL transmission in multi-beam operation. In this disclosure, several solutions are proposed to support a unified co-beam pointing design, including a joint co-beam pointing design scenario, a separate co-beam pointing design scenario, and a hybrid co-beam pointing design scenario. Further, default common beam indication design scenarios are also considered and proposed. The unified common beam design includes a common beam identification design and a common beam indication. For three cases, the mapping between the configuration beam and the number of bits or the mapping between the configuration beam and the time slot of the uplink signal received by the base station (e.g., the gNB) is intended to distinguish whether the configuration beam is a normal beam. Then, when the indication Transmission Configuration Indication (TCI) is not present, a method is proposed for determining a common beam of a different scenario.

Advantageous effects of some embodiments of the invention include at least one of: 1. and defining unified common beam indication of uplink and downlink in multi-beam transmission, and considering different common beam indication scenes. 2. Several common beam identification designs are proposed to distinguish whether the indicated mean is a common beam, and different common beam indication methods are proposed for different scenarios.

Fig. 2 illustrates that in some embodiments, one or more User Equipments (UEs) 10 and base stations (e.g., gnbs) 20 for communicating in a communication network system 30 are provided in accordance with an embodiment of the invention. The communication network system 30 is, for example, a Multiple Input Multiple Output (MIMO) system. The communication network system 30 includes one or more UEs 10 and a base station 20. One or more UEs 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12, transceiver 13. The base station 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22, the transceiver 23. The

processor

11 or 21 may be configured to implement the proposed functions, processes and/or methods described in the present specification. The radio interface protocol layer may be implemented in the

processor

11 or 21. The

memory

12 or 22 is operatively coupled to the

processor

11 or 21 and stores various information to operate the

processor

11 or 21. The

transceiver

13 or 23 is operatively coupled to the

processor

11 or 21, and the

transceiver

13 or 23 transmits and/or receives radio signals.

The

processor

11 or 21 may include an Application Specific Integrated Circuit (ASIC), other chipset, logic circuit, and/or data processing device.

Memory

12 or 22 may include Read Only Memory (ROM), random Access Memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. The

transceiver

13 or 23 may include baseband circuitry that processes radio frequency signals. When the embodiments are implemented in software, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The modules may be stored in memory 12 or 222 and executed by

processor

11 or 21. The

memory

12 or 22 may be implemented within the

processor

11 or 21 or external to the

processor

11 or 21, in which case they can be communicatively coupled to the

processor

11 or 21 via various means as is known in the art.

In some embodiments, processor 11 is configured to determine that one or more transmission configurations from base station 20 indicate a TCI state, wherein the one or more TCI states comprise one or more reference signals RS; determining one or more beams from the base station 20, wherein the one or more beams are for multi-beam operation; identifying one or more common beams from the one or more beams according to the one or more RSs; and using the one or more common beams for downlink DL reception and uplink UL transmission in the multi-beam operation. This may solve the problems in the prior art, define a uniform common beam indication for data and control transmission/reception of DL and UL in multi-beam operation, enhance the common beam design for DL and UL data and control transmission/reception in multi-beam operation, provide good communication performance, and/or provide high reliability.

In some embodiments, the processor 21 is configured to configure the UE20 with one or more transmission configuration indications, TCI, states, wherein the one or more TCI states comprise one or more reference signals, RSs; configuring one or more beams to the UE20, wherein the one or more beams are for multi-beam operation; identifying one or more common beams from the one or more beams according to the one or more RSs; and using the one or more common beams for downlink DL reception and uplink UL transmission in the multi-beam operation. This may solve the problems in the prior art, define a uniform common beam indication for data and control transmission/reception of DL and UL in multi-beam operation, enhance the common beam design for DL and UL data and control transmission/reception in multi-beam operation, provide good communication performance, and/or provide high reliability.

Fig. 3 illustrates a method 200 of common beam determination performed by a User Equipment (UE) in accordance with an embodiment of the present invention. In some embodiments, the method 200 includes: step 202, the UE determines one or more transmission configuration indication TCI status from a base station, wherein the one or more TCI status comprises one or more reference signals, RSs, step 204, the UE determines one or more beams from the base station, wherein the one or more beams are used for multi-beam operation, step 206: the UE identifies one or more common beams from the one or more beams according to the one or more RSs, step 208: the UE uses the one or more common beams for downlink DL reception and uplink UL transmission in the multi-beam operation. This may solve the problems in the prior art, define a uniform common beam indication for data and control transmission/reception of DL and UL in multi-beam operation, enhance the common beam design for DL and UL data and control transmission/reception in multi-beam operation, provide good communication performance, and/or provide high reliability.

Fig. 4 illustrates a method 300 of common beam determination performed by a base station in accordance with an embodiment of the present invention. In some embodiments, the method 300 includes: step 302, the base station configures one or more transmission configuration indicators TCI status to a user equipment UE, wherein the one or more TCI status includes one or more reference signals RS, step 304, the base station configures one or more beams to the UE, wherein the one or more beams are used for multi-beam operation, step 306: the base station identifies one or more common beams from the one or more beams according to the one or more RSs, step 308: the base station uses the one or more common beams for downlink DL reception and uplink UL transmission in the multi-beam operation. This may solve the problems in the prior art, define a uniform common beam indication for data and control transmission/reception of DL and UL in multi-beam operation, enhance the common beam design for DL and UL data and control transmission/reception in multi-beam operation, provide good communication performance, and/or provide high reliability.

In one embodiment of the invention, the one or more common beams are indicated according to the one or more RSs associated with the one or more beams. In one embodiment of the invention, the TCI state of the base station configuration is only one. In one embodiment of the invention, when there is only one RS in one TCI state, the RS is associated with the common beam for both the DL reception and/or the UL transmission in the multi-beam operation. In one embodiment of the present invention, the RS includes DL RS and/or UL RS. In one embodiment of the present invention, the DL RS includes channel state information CSI RS. In one embodiment of the present invention, the UL RS includes a sounding reference signal SRS. In an embodiment of the invention, the common beam is indicated using radio resource control, RRC, signaling and medium access control, MAC, control element, CE, signaling. In one embodiment of the present invention, the one TCI state is activated by MAC CE signaling, and a downlink control information DCI field is used to indicate a beam in one TCL state. In one embodiment of the invention, when the indication beam in the one TCI state is not the common beam, and if there are other common beams associated with the RS in the TCI state, the UE performs the DL reception and the UL transmission in the multi-beam operation using the common beam having the lowest index in the TCI state. In one embodiment of the invention, when the UE is configured with the beam associated with the RS of the TCI state, the method further comprises the UE determining a mapping between the beam and the RS.

In one embodiment of the present invention, the UE identifying the one or more common beams from the one or more beams according to the one or more RSs includes: the UE identifies the one or more common beams from the beams according to the mapping of the beams to the RSs. In one embodiment of the invention, the RS includes parameters including at least one of: a number of bits; or a time slot of an UL signal received by the base station. In one embodiment of the present invention, the UE determines a mapping between the beam and the RS through system information. In one embodiment of the present invention, the UE identifies the one or more common beams from the beams according to the mapping of the beams and the RSs, including: the UE performs beam measurement on the beam according to the mapping of the beam and the RS; the UE reports the beam measurement to the base station; the UE receives a first indication of the one or more common beams from the base station, wherein the first indication of the one or more common beams includes a first selection of the one or more common beams by the base station according to the beam measurements. In one embodiment of the present invention, the UE identifies the one or more common beams from the beams according to the mapping of the beams and the RSs, including: the UE performing UL beam scanning; the UE sends the UL RS configured in the TCI state to the base station; and the UE receiving a second indication of the one or more common beams from the base station, wherein the second indication of the one or more common beams includes a second selection of the one or more common beams by the base station according to the UL RS.

In one embodiment of the present invention, the one or more common beams depend on the UL RS associated, wherein the UL RS is a signal most recently received by the base station. In one embodiment of the invention, the TCI state is activated by MAC CE signaling, and the application downlink control information DCI field indicates that the one or more beams are in the one or more TCI states for a scheduling time. In one embodiment of the invention, when one or more indicated beams in the one or more TCI states within the scheduled time are not the one or more common beams, the UE uses the most recently indicated common beam for the DL reception and the UL transmission prior to the scheduled time in the multi-beam operation. In one embodiment of the invention, the method is performed in a joint common beam indication mode, a separate common beam indication mode, a hybrid common beam indication mode or a default common beam indication mode.

In one embodiment of the invention, when the method is performed in the joint common beam indication mode, the UE uses the same common beam for the DL reception and the UL transmission in the multi-beam operation. In one embodiment of the invention, for the joint co-beam indication scheme, both the DL reception and the UL transmission are indicated by only one common beam, and when only one RS is in a single TCI state, the RS is associated with the common beam for both the DL reception and the UL transmission. In one embodiment of the present invention, the RS is the DL RS or the UL RS.

In one embodiment of the invention, for the joint common beam indication scheme, a combination of K beams associated with a flag is used to identify the common beam, where K is greater than 1. In one embodiment of the present invention, if several of the K beams are the common beam, the common beam is determined with a flag value corresponding to each beam. In one embodiment of the present invention, if the DL RS provides the common beam, the base station selects a beam associated with the number of bits in the flag through the reporting CSI from the UE, if the UL RS provides the common beam, the base station selects a beam associated with the number of bits in the flag through the SRS from the UE, the selected beam depending on an associated uplink signal received at the base station in a most recently received signal including the reporting CSI or the SRS, and a combination of K beams and a flag is used to identify whether the indicated beam is the common beam. In one embodiment of the present invention, for the joint common beam indication mode, each beam is used for one time slot unit, the base station selects the beam by the most recently received signal including reporting CSI or SRS, each signal received by the base station corresponds to one time slot, and whether the selected beam is the common beam is identified by the correspondence between the time slot and the beam.

In one embodiment of the invention, when the method is performed in the split common beam indication mode, the UE applies independent common beams for the DL reception and the UL transmission, respectively, in the multi-beam operation. In one embodiment of the present invention, wherein the one or more RSs of M TCIs provide quasi-co-located QCL hypotheses for the DL reception, the one or more RSs of N TCIs provide spatial filters for the UL transmission, and one or more candidate common beams for the DL reception and the UL transmission are contained in the M TCIs and the N TCIs, respectively, where M is greater than or equal to 1 and N is greater than or equal to 1. In one embodiment of the invention, for the DL reception or the UL transmission, when there is only one TCI state, the TCL state includes only one RS to provide a QCL assumption for the DL reception or the spatial filter for the UL transmission, the beam associated with the RS being the common beam for the DL reception or the UL transmission in the multi-beam operation. In one embodiment of the present invention, when the RS is associated with a plurality of K DL beams and L UL beams contained in the TCI state, the RS is configured to indicate whether k×l beam pairs include the one or more common beams.

In one embodiment of the invention, when the method is performed in the split common beam indication mode and when only one TCI state contains only one RS providing a reference for QCL or the spatial filter, the beam associated with the RS is the common beam for the DL reception or the UL transmission. In one embodiment of the present invention, when the method is performed in the separate common beam indication mode and when the base station performs beam scanning, the UE performs beam measurement, and after measuring the beam, the UE transmits the UL RS to the base station at a slot position associated with the measured beam, and the base station measures the UL RS and selects an optimal UL beam to obtain a beam pair. In one embodiment of the present invention, when the method is performed in the split common beam indication mode and there is only one TCI state, both DL beams associated with DL RSs and UL beams associated with UL RSs are configured in the TCI state. In one embodiment of the invention, when the method is performed in the split common beam indication mode and only one TCI state, and if neither the indicated DL beam nor the indicated UL beam of the indicated beam pair is a DL common beam and a UL common beam, the UE uses the common beam with the lowest beam pair index in the TCI state for the DL reception and the UL transmission in the multi-beam operation.

In one embodiment of the invention, when the method is performed in the split common beam indication mode and only one TCI state, if an indicated beam pair is not the common beam but an indicated DL beam or an indicated UL beam of the indicated beam pair is a DL common beam or an UL common beam, the UE uses the common beam with the lowest beam pair index for DL and UL indications in TCI state, wherein the lowest beam pair includes the DL or UL common beam related to the indicated common beam pair. In one embodiment of the invention, when the method is performed in the split common beam indication mode, when the UE is configured with a plurality of TCI states, when the common beam does not exist in an indicated TCI state, and if neither an indicated DL beam nor an indicated UL beam of the indicated beam pair is a DL common beam nor an UL common beam, the UE performs the DL reception and the UL transmission using the latest indicated common beam before a scheduling time. In one embodiment of the present invention, when the method is performed in the split common beam indication mode, when the UE configures a plurality of TCI states, when the common beam does not exist in an indicated TCI state, and if a DL beam or an UL beam of an indicated common beam pair is the common beam, the UE performs the DL reception and the UL transmission using a latest indicated common beam before a scheduling time, wherein the indicated common beam includes the DL or UL common beam related to the indicated common beam pair within the scheduling time. In one embodiment of the invention, when the method is performed in the hybrid common beam indication mode, the UE uses a first type of common beam configured for the DL reception and the UL transmission in the multi-beam operation and a second type of common beam configured for only the DL reception or the UL transmission in the multi-beam operation.

In one embodiment of the present invention, one or more RSs configured in one or more TCLs provide the first type of common beam and the second type of common beam. In one embodiment of the present invention, when the RS is associated with a plurality of K DL beams, L UL beams, S beams are applied to the DL reception and the UL transmission included in the TCI state, the RS is configured to indicate whether K times L plus S beam pairs include one or more common beams. In one embodiment of the invention, the first type of common beam and the second type of common beam have different priorities. In one embodiment of the invention, the first type of common beam has a higher priority than the second type of common beam. In one embodiment of the present invention, when the common beam in the TCI state does not exist, the first type common beam and the second type common beam configured with higher priority included in the TCI state indicated by the latest scheduling time are regarded as the common beam. In one embodiment of the present invention, the base station configures a time window for the UE for distinguishing whether the common beam or the common beam pair is valid. In one embodiment of the invention, if there is not only the first type of common beam within a window time, the UE uses the common beam with the lowest index in the TCI state for the DL reception and the UL transmission in the multi-beam operation; and/or if only the second kind of common beam is included within the window time, the UE uses the common beam with the lowest beam pair index for the DL reception and the UL transmission in the multi-beam operation in the TCI state.

In one embodiment of the present invention, when the method is performed in the hybrid common beam indication mode, K times L beam pairs are obtained by combining K DL beams associated with a plurality of DL RSs and L UL beams associated with a plurality of UL RSs, and K times L plus S beams/pairs are available in total for the DL reception and the UL transmission. In one embodiment of the invention, when the method is performed in the hybrid common beam indication mode, if there is one selected beam, which indexes from the first beam to the s-th beam, the UE measures the beam with the RS, providing only the common beam for the DL reception or the UL transmission; and/or if there is a selected beam having an index from a first beam pair to K times an L-th beam pair, the UE uses the RS to measure the beam, providing the common beam for the DL reception and the UL transmission. In one embodiment of the present invention, when the method is performed in the default common beam indication mode, the UE uses one or more default common beams as the one or more common beams when DL and UL default beams are aligned. In one embodiment of the invention, the one or more default common beams comprise the latest common beam with the lowest index contained in one of the scheduled times. The first beam in the following embodiments refers to beam1, and the s-th beam refers to the beam in the following embodiments.

In some embodiments, the unified common beam design for DL and UL beam indication includes a joint common beam indication mode, a separate common beam indication mode, and a mixed common beam indication mode. For the joint common beam indication scheme, different DL and UL channels use the same common beam. For separate common beam indications, separate common beams are applied for DL and UL indications, respectively, e.g. one common beam for DL transmission. For the hybrid common beam indication, both the downlink and uplink are configured with one common beam, while the other type of common beam is configured for DL or UL indication only. Further, a default common beam indication mode is also considered and proposed. Regarding the unified common beam design for DL and UL beam indication, the design is based on the common beam identification design and the common beam indication design. Further, in some embodiments of the present invention, the beams are both associated with the RS. One RS may represent one beam, but one beam may be represented by a plurality of RSs, and an indication of the beam by the RS is indicated by TCI. In other words, the source reference RS in the TCI state, which is indicated by the QCL, provides a common beam for DL reception (e.g., PDSCH reception).

Joint common beam indication for DL and UL:

for joint common beam indication, DL and UL transmissions are indicated by only one common beam. For joint co-beam indication, the source RS in TCI state provides a common beam for PDSCH reception and PUSCH transmission. The beam indication directly references the associated source reference RS without loss of generality. Some embodiments assume that K (K.gtoreq.1) beams are configured for multi-beam transmission. When only one source RS is in a single TCI state, i.e., k=1, the source RS is associated with a common beam for DL and UL transmissions, where the source RS may be a DL RS (e.g., csi_rs) or UL RS (e.g., SRS).

Public beam identification design:

in some embodiments, the gNB and the UE are configured with multiple beams associated with multiple RSs, i.e., K >1. In this scenario, some embodiments introduce a set flag= { flag1, flag2, … …, flag } to distinguish whether the indicated beam is a common beam. In particular, some embodiments associate a parameter flag with the i-th beam, which for simplicity is further denoted as beai, where i=1, 2. Some embodiments set flag=1 if inamine is a common beam, otherwise flag=0. As shown in table 1, there are a plurality of candidate common beams, and beam2, beam3, and beam k associated with flag2=1, flag3=1, and flagk=1 are candidate common beams.

Table 1:

beam index	Sign mark
		Beam ₁	flag ₁ ＝0
Beam ₂	flag ₂ ＝1
		Beam ₃	flag ₃ ＝1
……	……
		Beam _K-1	flag _K-1 ＝0
Beam _K	flag _K ＝1

The advantages of some embodiments are: the common beam can be easily identified by a combination of K beams associated with the logo. Without the definition of the flag, the UE may confuse the common beam with other beams.

The relation between the beam index and the flag value (as shown in table 2) is notified to the UE through the system information. The UE will make CSI measurements when it receives a beam scan from the gNB and then report the measurement results to the gNB. Based on the reported CSI measurements, the gNB selects a beam associated with the number of bits in the flag. Since one or more UL RSs, i.e., SRS, are configured in the TCI state, when the UE performs UL beam scanning, the uplink signal received by the gNB is SRS rather than reported CSI measurements. The proposed design may also be applied to scenarios where the gNB sends an SRS Resource Indicator (SRI) to indicate the indicated beam to the UE after measuring the SRS received from the UE. The indicated beam depends on the associated uplink signal, which is the most recently received signal by the base station.

In addition, some embodiments also propose a design based on a time domain resource allocation field for joint beam identification to distinguish whether the indicated beam is a common beam. The plurality of source RSs and the plurality of beams included in the TCI state are associated with the plurality of source RSs. Some embodiments also assume that K beams are configured for multi-beam transmission. The K slot positions are configured for DL and UL transmissions. Specifically, as shown in table 2, some embodiments introduce a set slot= { slot1, slot2,.. slot, where each parameter in a slot refers to the slot position assigned to the indicated beam.

Table 2:

beam index	Sign mark
		Beam ₁	slot ₁
Beam ₂	slot ₂
		Beam ₃	slot ₃
……	……
		Beam _K-1	slot _K-1
Beam _K	slot _K

Also, for designs based on time domain resource allocation fields. When the gNB performs beam scanning, the UE makes beam measurements and then reports to the gNB at slot positions associated with the measurement beams. When the gNB receives the reported beam measurements (CSI measurements) at the slot positions, the gNB selects the associated beam. For UL scanning, the UE sends UL-RS to the gNB at the relevant slot position for beam measurement. The indicated beam depends on the associated uplink signal, which is the most recently received signal by the gNB.

Common beam indication design:

in the relay-15/16 NR, gNB configures multiple TCI states for UE through PDSCH-Config and other high-level parameters for multi-beam transmission. After one or more TCI states are activated by MAC CE signaling, a DCI field is applied to indicate a beam for DL reception. When the UE configures a TCI state, beam indication can be achieved only by using RRC signaling and MAC CE signaling. In other words, when one or more TCIs are activated, all configured RSs are activated, i.e., the provided beam is also activated. When the UE configures multiple TCI states, more than one TCI state is activated and the DCI field carried by the PDCCH is used to schedule DL reception. That is, the DCI signaling selects one state, and the UE uses a beam associated with an RS configured with a selected TCI (TCI indicated in some embodiments of the present invention) in the scheduling DCI field.

If neither the indicated DL beam nor UL beam of the indicated beam pair is a DL common beam nor UL common beam, the UE uses the lowest indexed common beam of the beam pair in the TCI state for DL and UL indication. As shown in table 5, when the index indicating Beam pair is 2, it is composed of DL Beam1 and UL Beam2, and neither DL Beam1 nor UL Beam2 is a common Beam for DL and UL Beam indication, and the Beam pair with index l+1 is regarded as a common Beam.

If the indicated beam pair is not a normal beam, but the indicated DL beam or UL beam of the indicated beam pair is a DL common beam or UL common beam, the UE uses the common beam with the lowest beam pair index for DL and UL indication in the TCI state, wherein the lowest beam pair includes the DL or UL common beam associated with the indicated common beam pair. As shown in table 5, when the index indicating the Beam pair is 2l+2, it is composed of DL Beam3 and UL Beam2, DL Beam3 is a common Beam of DL, and the Beam pair with the index 2l+1 is used as the common Beam.

In some embodiments, when only one TCI state is configured by the gNB, if the indicated beam is not a common beam, the UE uses the lowest indexed common beam in the TCI for DL and UL indications if there are other common beams associated with the reference RS in the TCI state. For example: beam2, beam3, beam k are also assumed to be the common beam provided in TCI. If the beam indicated in the beam index of both schemes (table 1 and table 2) is beam4 (not a common beam), since all beams are provided by RSs configured in the TCI, all beams are activated when the TCI is activated by the MAC CE. The common beam with the lowest index, i.e., beam2, of the active beams is selected. However, the beam indicated in the TCI state of the scheduling DCI does not always exist, and when there are a plurality of TCI states through RRC configuration, if the RS in the TCI state does not provide any candidate common beam, a problem may occur in that any RS in the indicated TCI state is not associated with the candidate common beam. In this case, RRC reconfiguration may cause signaling overhead. In some embodiments, the UE performs DL reception and UL transmission using the most recently indicated common beam before the scheduling time when the common beam does not exist in the indicated TCI state. For example, as shown in fig. 5, there is no common beam in the TCI at scheduling time n, and the UE uses the common beam indicated at time n-2.

Separate common beam indication for DL and UL:

for separate common beam indications, some embodiments assume that source RSs of M TCIs provide QCL hypotheses for DL transmissions, while source RSs of N TCIs provide spatial filters for UL transmissions, where M > =1, and N > =1. Candidate common beams for DL reception and UL transmission are included in M TCIs and N TCIs, respectively.

Public beam identification design:

for DL reception or UL transmission, when only one TCI state (i.e., m=n=1) contains only one source RS providing a reference for QCL or spatial filter, the beam associated with the source RS is the common beam for DL or UL transmission.

Now consider the case where multiple source reference signals are contained in each TCI state, in which case both the TCI state for DL indication and the TCI state for UL indication have multiple source RSs (i.e., DL-RS and UL-RS). Each DL (UL) beam is directed to an associated DL (UL) source RS. Some embodiments assume that the UE is configured with K DL beams and L UL beams. Some embodiments introduce a set of K parameters, dlCommonbeam flag, i.e., dlCommonbeam flag= { Dlflag1, dl flag2,.. D.i., dlflag K } to indicate whether the indicated Dl beam associated with the reference RS is a common beam, and a set of L parameters, ul Commonbeam flag, i.e., ulCommonbeam flag= { Ulflag1, ul flag2, &., ulflag L }, to indicate whether the indicated Ul beam associated with the source RS is a common beam. For DL (UL) transmissions, some embodiments have flag=1 when the beam with the index DL Beami (UL Beami) is a candidate common beam, otherwise flag=0. As shown in table 3, DL beam2, DL beam3, and DL beam k are candidate common beams for DL transmission, and UL beam1 and UL beam l are candidate beams for uplink transmission. Note that K and L are not always the same.

Table 3:

by combining K DL beams associated with multiple DL RSs and L UL beams associated with multiple UL RSs, some embodiments may obtain a total of k×l beam pairs, six of which are common beams. As shown in table 4, the set common beampair flag= { pair flag1, pair flag2, the term "pahfagkl" means whether the beam pair is a common beam.

Table 4:

as shown in table 4, the common beam pair flag is configured to indicate whether the beam pair is a common beam. When the gNB performs beam scanning, the UE performs beam measurement, and the UE selects the best beam and reports to the gNB. Meanwhile, the UE performs UL beam scanning, the gNB measures UL-RS received from the UE, and selects the best beam. After DL and UL scanning, beam pairs associated with beam pair indexes are indicated according to the most recently received CSI report and UL reference RS. The indicated beam pairs are configured with a common beam pair flag. In table 4, beam pairs having pairing=1, i=l+1, 2L, 2l+1, 3×l, (K-1) l+1 or k×l are explicitly indicated as common beams.

In addition, table 5 illustrates a design of separate common beam identification based on the time domain resource allocation domain. There are multiple reference RSs associated with the multiple K DL beams and the L UL beams contained in the TCI state, k×l slot positions for indicating whether the beam pair is a common beam. In particular, some embodiments introduce a set slot= { slot1, slot 2..the term "is used herein, slotKL }, wherein each parameter in a slot refers to a slot position allocated for beam transmission, and the beam index is associated with a kxl parameter in the slot. Some embodiments also assume that DL beam2, DL beam3, and DL beam k associated with the DL reference RS are candidate common beams and UL beam1 and UL beam l associated with the UL reference RS are candidate beams for UL transmission.

Table 5:

for the design based on the time domain resource allocation domain, when the gNB performs beam scanning, the UE performs beam measurement, and after measuring the beam, the UE transmits UL reference RS to the gNB at a slot position associated with the measured beam. The gNB measures the UL reference RS and selects the best UL beam, resulting in a pair of beams. For example, when the UE measures DL beam2 and reports to the gNB, the UE then transmits UL RS from slot l+1 to slot 2×l to the gNB for UL beam measurement. If the best UL beam is associated with either slot l+1 or slot 2×l, the resulting beam pair is a common beam.

Common beam indication design:

similar to the above embodiments, when the UE is configured with one TCI state, beam indication can be achieved using only RRC signaling and MAC CE signaling. When the UE configures multiple TCI states, more than one TCI state is activated. DL reception is indicated by TCI in the scheduling DCI field.

If the indicated beam pair is not a common beam, but the indicated DL beam or UL beam of the indicated beam pair is a DL common beam or UL common beam, the UE uses the common beam with the lowest beam pair index for DL and UL indication in the TCI state, wherein the lowest beam pair includes the DL or UL common beam associated with the indicated common beam pair. As shown in table 5, when the index indicating the Beam pair is 2l+2, it is composed of DL Beam3, which is a normal Beam of DL, and UL Beam2, and the Beam pair with the index 2l+1 is used as a common Beam.

The relation between the beam pair index and the value of the set common beam pair flag, and the relation between the beam pair index and the slot index may be notified to the UE through system information. In some embodiments, when the UE is configured with multiple TCI states, the indicated TCI state is selected by the scheduling DCI field after the TCI state is activated. However, since the candidate common beam is provided by the reference RS in a plurality of TCI states configured through RRC, the indicated beam in the TCI state of the scheduling DCI does not always exist, and if the reference RS in the indicated TCI state does not provide the common beam, a problem may occur in that any reference RS in the TCI state is not associated with the candidate common beam. In this case, RRC reconfiguration may cause signaling overhead. In fig. 6, when the indicated beam at the scheduling time n is beam pair1 and there is no candidate common beam in the indicated TCI state, the common beam indicated at the time n-1 is taken as the common beam. Thus, when the common beam does not exist in the indicated TCI state, if neither the indicated DL beam nor the indicated UL beam of the indicated beam pair is the DL common beam nor the UL common beam, the UE performs DL reception and UL transmission using the latest indicated common beam before the scheduling time.

In some embodiments, when the reference RS for DL transmission and the reference RS for UL transmission are configured separately. DL-RS is associated with only DL candidate common beams, while UL-RS is associated with only UL candidate common beams. In this scenario, the indicated beam pair may result in problems including UL common beams or DL common beams, e.g., the beam pair indexed 1 and the beam pair l+2 in table 5. As shown in fig. 6, when the beam indicated in the schedule n is beam pair1 and there is no candidate common beam in the TCI state, the common beam indicated by the n-2 slot is used as the common beam. Thus, in some embodiments, when the common beam does not exist in the indicated TCI state, and the DL or UL beam of the indicated common beam pair is the common beam, the UE performs DL reception and UL transmission using the most recently indicated common beam before the scheduling time n, wherein the indicated common beam includes the DL or UL common beam associated with the indicated common beam pair in the scheduling time n.

Hybrid common beam indication for DL and UL

For the hybrid common beam indication, there are two types of common beam configurations for DL and UL, i.e., one Type of common beam is configured for DL and UL, which is referred to as Type1 for simplicity, and the other Type of common beam is configured for DL or UL only, which is referred to as Type2 for simplicity. That is, the RS configured in the TCI provides a common beam for DL reception, a common beam for UL transmission, and a common beam for DL reception and UL transmission.

Public beam identification design:

similar to the above embodiment, a plurality of RSs are configured in the TCI state, and a plurality of beams directly reference the associated RSs. The UE is configured with K DL beams and L UL beams, and further, some embodiments assume that S beams can be applied for DL reception and UL transmission, where Kc is a common beam. Similar to tables 3 and 4, it is assumed that DL beam2, DL beam3, and DL beam k are candidate common beams for DL reception, and UL beam1 and UL beam l are candidate beams for uplink transmission. K DL beams associated with the plurality of DL RSs and L UL beams associated with the plurality of UL RSs are combined to obtain k×l beam pairs, 6 of which are common beams. Thus, in some embodiments, a total of kxl+s beams (pairs) are available for DL and UL transmissions, where kc+6 is a common beam (beam pair).

As shown in table 6, the set flag= { flag1, flag2, … …, flag kl+s } is introduced to indicate whether the beam or beam pair is a common beam. Some embodiments have flag=1 when the common with index Beami (Beam pairii) is a candidate common, otherwise flag=0. Let kc=2, beam1 and beam2 are candidate common beams for DL and UL transmissions.

In addition, some embodiments also propose designs based on time domain resource allocation fields. Similarly, k×l+s slot positions are configured to distinguish whether a beam (beam pair) is a common beam. In particular, we introduce set slot= { slot1, slot 2..the term "is used herein, slotKL + S, wherein each parameter in a slot represents a slot position and the beam index is associated with a kxl parameter in the slot.

Table 6:

beam (beam pair) index	Sign mark	Time slots
			Beam pair ₁	flag ₁ ＝0	slot ₁
Beam pair ₂	flag ₂ ＝0	slot ₂
			……	……	……
Beam pair _KL	flag _KL ＝1	slot _K×L
			Beam ₁	flag _KL+1 ＝1	slot _K×L+1
Beam ₂	flag _KL+2 ＝1	slot _K×L+1
			Beam ₃	flag _KL+3 ＝0	slot _K×L+1
……	……	……
			Beam _S	flag _KL+S ＝0	slot _K×L+S

For the mixed common beam scenario, two common beam identification designs based on the introduction of the flag and the time domain resource allocation field are similar to the embodiments described above. When the gNB performs beam scanning, the UE performs beam measurement and selects the best beam. If the index of the selected Beam is from Beam1 to Beam s, i.e. the UE measures the Beam of the Beam with RS, only one common Beam is provided for DL or UL, the identification design is similar to the above described embodiments. If the index of the selected Beam is from Beam pair1 to Beam pair kl, i.e. the UE uses the RS measurement Beam, a common Beam is provided for DL reception and UL transmission, the identification design is similar to the above-described embodiment.

Common beam indication design:

similar to the above embodiments, when the UE configures one TCI state, beam indication can be achieved using only RRC signaling and MAC CE signaling. When the UE configures multiple TCI states, the multiple TCI states are activated and the UE decodes the indication beam carrying the RS association of the scheduling DCI field.

If the indicated beam pair is not a common beam, but the indicated DL beam or UL beam of the indicated beam pair is a DL common beam or UL common beam, the UE uses the common beam with the lowest beam pair index for DL and UL indication in the TCI state, wherein the lowest beam pair includes the DL or UL common beam associated with the indicated common beam pair. As shown in table 5, when the index indicating the Beam pair is 2l+2, it is composed of DL Beam3 and UL Beam2, DL Beam3 is a common Beam of DL, and the Beam pair with the index 2l+1 is used as the common Beam.

There may be two types of common beams in the TCI state. Therefore, it is necessary to prioritize the different types of common beams. To further reduce delay and signaling overhead, the type1 (type 1) common beam is predefined to have a higher priority than the type2 (type 2) common beam. Relation between beam (beam pair) index and commonbeampair flag value, relation between beam (beam pair) index and slot, priority of common beam of type1 and type2 informs UE through system information.

The common beam in the TCI state is not always present and if the RS in the TCI state does not provide a common beam, a problem may occur in that any RS in the active TCI state is not associated with a candidate common beam. In this case, RRC reconfiguration may cause signaling overhead. The two common beams configured with higher priorities contained in the TCI state of the latest schedule time indication are considered as common beams. Since the type1 or type2 common beam does not always occur at the same time interval, for example, the latest type1 common beam may be received long before and thus cannot be regarded as an applicable common beam. Thus, the gNB configures a time window Tw for the UE to distinguish whether the common beam or beam pair in FIG. 7 is valid.

At the scheduling time n, when there is no common Beam in the indicated TCI, the UE determines the common Beam using the latest type 1 indicated common Beam before the scheduling time n, if the type 1 common Beam, for example Beam2 in fig. 7, is configured within the time window Tw, and if not only the type 1 common Beam is included in the time window Tw, the UE adopts the same scheme similar to the above-described embodiment. If only the type 2 common beam is included in the time window Tw, the UE adopts the same scheme similar to the above-described embodiment.

Default common beam indication for DL and UL:

default beam-based indications are typically used for Release-15/16. In Release-15/16, the default value for DL reception is the QCL assumption of the monitored CORESET with the lowest index in the most recent slot, while for the default PUCCH/PUSCH Tx beam, the UE refers to the TCI state of the configured CORESET with the lowest index. Thus, DL and UL default beams are not always aligned. In addition, the reference RS resources of the DL and UL default beams in Relay 15/16 are both DL RSs, and flexibility is lacking.

In some embodiments, for default beam indication designs, due to misalignment between DL and UL default beams as set forth in Release-15/16, only the default common beam can be used as the common beam when DL and UL default beams are aligned. Further, considering the case of DL and UL default beam alignment, the default common beam is the indicated beam contained in the TCI state of the latest scheduling time indication according to the rule of the default beam in Release-15/16. For example, in FIG. 5, the default common beam is beam1 indicated by time n-1, not the common beam, but some embodiments may also obtain the default common beam if there is indeed another commonality in scheduling time n, otherwise the default common beam needs to be found before time n. Thus, in some embodiments, the default common beam is the most recent common beam with the lowest index contained in one of the scheduling times.

The commercial benefits of some embodiments are as follows. 1. Solves the problems in the prior art. 2. Enhancing Downlink (DL) and Uplink (UL) data in multi-beam transmission and controlling common beam design of transmission/reception. 3. A unified common beam indication is defined for UL and DL in multi-beam transmission. 4. Different common beam indication scenarios are considered. 5. Several common beam identification designs are proposed for distinguishing whether or not an indicated mean is a common beam. 6. Different common beam indication methods are proposed for different scenarios. 7. Providing good communication performance. 8. Providing high reliability. 9. Some embodiments of the invention are implemented by 5G-NR chipset vendors, V2X communication system development vendors, automotive manufacturers including cars, trains, trucks, buses, bicycles, motorcycles, helmets, etc., drones, smart phone manufacturers, public safety communication devices, AR/VR device manufacturers (e.g., games, meetings/seminars, educational purposes). Some embodiments of the invention are a combination of "technologies/procedures" that may be employed in the 3GPP specifications to create the end product. Some embodiments of the invention propose a technical mechanism.

Fig. 8 is a block diagram of a system for wireless communication according to an embodiment of the present invention. The embodiments described herein may be implemented in a system using any suitable configuration of hardware and/or software. FIG. 8 illustrates an example system 700 for one embodiment that includes Radio Frequency (RF) circuitry 710, baseband circuitry 720, application circuitry 730, memory/storage 740, display 750, camera 760, sensor 770, and input/output (I/O) interface 780 coupled to one another at least as shown. Application circuitry 730 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. A processor may comprise any combination of general-purpose processors and special-purpose processors, such as graphics processors, application processors, and the like. The processor may be coupled to the memory/storage device and configured to execute instructions stored in the memory/storage device to enable various applications and/or operating systems running on the system.

Baseband circuitry 720 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may comprise a baseband processor. The baseband circuitry may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency shifting, and the like. In some embodiments, baseband circuitry may provide communications compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry may support communication with an Evolved Universal Terrestrial Radio Access Network (EUTRAN) and/or other Wireless Metropolitan Area Networks (WMANs), wireless Local Area Networks (WLANs), wireless Personal Area Networks (WPANs). Embodiments in which the baseband circuitry is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

In various embodiments, baseband circuitry 720 may include circuitry that operates with signals that are not strictly considered to be at baseband frequencies. For example, in some embodiments, the baseband circuitry may include circuitry that operates with signals having intermediate frequencies between baseband frequencies and radio frequencies. The RF circuitry 710 may use modulated electromagnetic radiation transmitted through a non-solid medium to effect communication with a wireless network. In various embodiments, the RF circuitry may include switches, filters, amplifiers, etc. to facilitate communication with the wireless network. In various embodiments, RF circuitry 710 may include circuitry that operates with signals that are not strictly considered to be at radio frequencies. For example, in some embodiments, the RF circuitry may include circuitry that operates with signals having intermediate frequencies between baseband frequencies and radio frequencies.

In various embodiments, the transmitter circuitry, control circuitry, or receiver circuitry discussed above with respect to the user equipment, eNB, or gNB may be embodied in whole or in part in one or more of RF circuitry, baseband circuitry, and/or application circuitry. As used herein, "circuitry" may refer to, be part of, or include the following: an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the electronic device circuitry may be implemented in or the functions associated with one or more software or firmware modules. In some embodiments, some or all of the baseband circuitry, application circuitry, and/or constituent elements of the memory/storage device may be implemented together on a system on a chip (SOC). Memory/storage 740 may be used to load and store information and/or instructions, for example, for the system. The memory/storage device for one embodiment may comprise any combination of suitable volatile memory, such as Dynamic Random Access Memory (DRAM), and/or non-volatile memory, such as flash memory.

In various embodiments, I/O interface 780 may comprise one or more user interfaces designed to enable user interaction with the system and/or a peripheral interface designed to enable peripheral interaction with the system. The user interface may include, but is not limited to, a physical keyboard or keypad, a touch pad, a speaker, a microphone, and the like. The peripheral device interface may include, but is not limited to, a non-volatile memory port, a Universal Serial Bus (USB) port, an audio jack, and a power interface. In various embodiments, the sensor 770 may comprise one or more sensing devices to determine environmental conditions and/or location information related to the system. In some embodiments, the sensors may include, but are not limited to, gyroscopic sensors, accelerometers, proximity sensors, ambient light sensors, and positioning units. The positioning unit may also be part of or interact with baseband circuitry and/or RF circuitry to communicate with elements of a positioning network, such as Global Positioning System (GPS) satellites.

In various embodiments, display 750 may include displays such as liquid crystal displays and touch screen displays. In various embodiments, system 700 may be a mobile computing device such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, a ultrabook, a smart phone, and the like. In various embodiments, the system may have more or fewer elements, and/or different architectures. The methods described herein may be implemented as a computer program, as appropriate. The computer program may be stored on a storage medium such as a non-transitory storage medium.

It will be appreciated by those of skill in the art that each of the units, algorithms and steps described and disclosed in the embodiments of the invention are implemented using electronic hardware or a combination of software and electronic hardware for a computer. Whether the function is implemented in hardware or software depends on the conditions of the application and the design requirements of the technical project. One of ordinary skill in the art may implement the functionality for each particular application in different ways without such implementation exceeding the scope of the present invention. It will be understood by those of ordinary skill in the art that reference may be made to the operation of the systems, devices and units in the embodiments mentioned above, as the operation of the systems, devices and units mentioned above are essentially the same. For ease of description and simplicity, these operations will not be described in detail.

It should be appreciated that the systems, devices, and methods disclosed in the embodiments of the present invention may be implemented in other ways. The above-described embodiments are merely exemplary. The division of cells is based solely on logic functions, while other divisions actually exist. It is possible that multiple units or elements are combined or integrated in another system. Certain features may be omitted or skipped. On the other hand, the mutual coupling, direct coupling or communicative coupling shown or discussed operates through some ports, devices or units, whether indirectly or communicatively via electrical, mechanical or other types of forms.

The units used for illustration as separate elements may or may not be physically separate. The units used for display may or may not be physical units, i.e. located at one site or distributed over a plurality of network units. Some or all of the units are used according to the purpose of the embodiment. Furthermore, each functional unit in each embodiment may be integrated in one processing unit, physically separate, or integrated with two or more units in one processing unit.

If the software functional unit is implemented and used and sold as a product, it may be stored in a readable storage medium in a computer. Based on this understanding, the solution proposed by the present invention can be implemented substantially or partly in the form of a software product. Alternatively, a part of the technical solution beneficial to the conventional technology may be implemented in the form of a software product. The software product in the computer is stored in a storage medium containing a plurality of commands for a computing device (e.g., a personal computer, a server, or a network device) to perform all or some of the steps disclosed in embodiments of the present invention. The storage medium includes a flash drive, a removable hard disk, a Read Only Memory (ROM), a Random Access Memory (RAM), a floppy disk, or other type of medium capable of storing program code.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but is intended to cover various arrangements included within the scope of the appended claims without departing from the broadest interpretation of the claims.

Claims

1. A method for determining a common beam by a user equipment UE, comprising:

the UE determining that one or more transmission configurations from a base station indicate a TCI state, wherein the one or more TCI states include one or more reference signals, RSs;

the UE determining one or more beams from the base station, wherein the one or more beams are for multi-beam operation;

the UE identifies one or more public beams from the one or more beams according to the one or more RSs; and

the UE uses the one or more common beams for downlink DL reception and uplink UL transmission in the multi-beam operation.

2. The method of claim 1, wherein the one or more common beams are indicated according to the one or more RSs associated with the one or more beams.

3. A method according to claim 1 or 2, characterized in that the TCI state of the base station configuration is only one.

4. A method according to claim 3, characterized in that when there is only one RS in one TCI state, the RS is related to the common beam of both the DL reception and/or the UL transmission in the multi-beam operation.

5. The method of claim 4, wherein the RS comprises DL RS and/or UL RS.

6. The method of claim 5 wherein the DL RS comprises channel state information CSIRS.

7. The method of claim 5, wherein the UL RS comprises a sounding reference signal, SRS.

8. The method according to any of claims 3 to 7, characterized in that the common beam is indicated using radio resource control, RRC, signaling and medium access control, MAC, control element, CE, signaling.

9. The method of claim 3, wherein the one TCI state is activated by MAC CE signaling, and a downlink control information, DCI, field is used to indicate a beam in one TCL state.

10. The method of claim 9, wherein the UE uses the common beam with the lowest index in the TCI state for the DL reception and the UL transmission in the multi-beam operation when the indicated beam in the one TCI state is not the common beam and if there are other common beams associated with the RS in the TCI state.

11. The method of claim 1 or 2, wherein when the UE is configured with the beam associated with the RS of the TCI state, the method further comprises the UE determining a mapping between the beam and the RS.

12. The method of claim 11, wherein the UE identifying the one or more common beams from the one or more beams according to the one or more RSs comprises:

the UE identifies the one or more common beams from the beams according to the mapping of the beams to the RSs.

13. The method according to claim 11 or 12, wherein the RS comprises parameters comprising at least one of:

a number of bits; or alternatively

The time slot of the UL signal received by the base station.

14. The method according to any of claims 11 to 13, wherein the UE determines a mapping between the beam and the RS by system information.

15. The method according to any of claims 12 to 14, wherein the UE identifying the one or more common beams from the beams according to the mapping of the beams to the RSs, comprises:

The UE performs beam measurement on the beam according to the mapping of the beam and the RS;

the UE reports the beam measurement to the base station;

the UE receives a first indication of the one or more common beams from the base station, wherein the first indication of the one or more common beams includes a first selection of the one or more common beams by the base station according to the beam measurements.

16. The method according to any of claims 12 to 15, wherein the UE identifying the one or more common beams from the beams according to the mapping of the beams to the RSs, comprises:

the UE performing UL beam scanning;

the UE sends the UL RS configured in the TCI state to the base station; and

the UE receives a second indication of the one or more common beams from the base station, wherein the second indication of the one or more common beams includes a second selection of the one or more common beams by the base station according to the UL RS.

17. The method of claim 16, wherein the one or more common beams depend on the UL RS associated, wherein the UL RS is the most recently received signal by the base station.

18. The method according to any of claims 11 to 17, characterized in that the TCI state is activated by MAC CE signaling, an application downlink control information, DCI, field indicating that the one or more beams are in the one or more TCI states for a scheduled time.

19. The method of claim 18, wherein the UE uses the most recently indicated common beam for the DL reception and the UL transmission prior to the scheduled time in the multi-beam operation when one or more indicated beams in the one or more TCI states within the scheduled time are not the one or more common beams.

20. The method according to any of claims 1 to 19, wherein the method is performed in a joint common beam indication mode, a separate common beam indication mode, a mixed common beam indication mode or a default common beam indication mode.

21. The method of claim 20, wherein the UE uses the same common beam for the DL reception and the UL transmission in the multi-beam operation when the method is performed in the joint common beam indication mode.

22. The method of claim 20 wherein for the joint co-beam indication scheme, both the DL reception and the UL transmission are indicated by only one common beam, the RS being associated with the common beam for both the DL reception and the UL transmission when only one RS is in a single TCI state.

23. The method of claim 22, wherein the RS is the DL RS or the UL RS.

24. The method of claim 20, wherein for the joint common beam indication, a combination of K beams associated with a flag is used to identify the common beam, wherein K is greater than 1.

25. The method of claim 24, wherein if a few of the K beams are the common beam, determining the common beam is performed using a flag value corresponding to each beam.

26. The method of claim 25, wherein if the DL RS provides the common beam, the base station selects a beam associated with the number of bits in the flag by reporting CSI from the UE, and if UL RS provides a common beam, the base station selects a beam associated with the number of bits in a flag by SRS from the UE, the selected beam being dependent on an associated uplink signal received at the base station in a most recently received signal including the reporting CSI or the SRS, a combination of K beams and a flag being used to identify whether the indicated beam is the common beam.

27. The method of claim 20, wherein for the joint common beam indication scheme, each beam is used for one slot unit, the base station selects the beam by the most recently received signal including reporting CSI or SRS, each signal received by the base station corresponds to one slot, and whether the selected beam is the common beam is identified by a correspondence of the slot to the beam.

28. The method of claim 20, wherein the UE applies separate common beams for the DL reception and the UL transmission, respectively, in the multi-beam operation when the method is performed in the split common beam indication mode.

29. The method of claim 28, wherein the one or more RSs of M TCIs provide quasi-co-located QCL hypotheses for the DL reception, wherein the one or more RSs of N TCIs provide spatial filters for the UL transmission, and wherein one or more candidate common beams for the DL reception and the UL transmission are contained in the M TCIs and the N TCIs, respectively, wherein M is greater than or equal to 1 and N is greater than or equal to 1.

30. The method of claim 28 or 29, wherein for the DL reception or the UL transmission, when there is only one TCI state, TCL state includes only one RS to provide a QCL assumption for the DL reception or the spatial filter for the UL transmission, the beam associated with the RS being the common beam for the DL reception or the UL transmission in the multi-beam operation.

31. The method of claim 28 or 29, wherein when the RS is associated with a plurality of K DL beams and L UL beams contained in the TCI state, the RS is configured to indicate whether K x L beam pairs include the one or more common beams.

32. The method of claim 20, wherein the beam associated with the RS is the common beam for the DL reception or the UL transmission when the method is performed in the split common beam indication mode and when only one TCI state contains only one RS providing a reference for QCL or the spatial filter.

33. The method of claim 20 wherein when the method is performed in the split common beam indication mode and when the base station performs beam scanning, the UE performs beam measurements, after measuring the beams, the UE transmits the UL RS to the base station at a slot position associated with the measured beams, the base station measuring the UL RS and selecting the best UL beam to obtain a beam pair.

34. The method of claim 20, wherein when the method is performed in the split common beam indication mode and there is only one TCI state, both DL beams associated with DL RSs and UL beams associated with UL RSs are configured in the TCI state.

35. The method of claim 20, wherein when the method is performed in the split common beam indication mode and only one TCI state, and if neither the indicated DL beam nor the indicated UL beam of the indicated beam pair is a DL common beam and a UL common beam, the UE uses the common beam with a lowest beam pair index in the TCI state for the DL reception and the UL transmission in the multi-beam operation.

36. The method of claim 20, wherein when the method is performed in the split common beam indication mode and only one TCI state, if an indicated beam pair is not the common beam but an indicated DL beam or an indicated UL beam of the indicated beam pair is a DL common beam or an UL common beam, the UE uses the common beam with a lowest beam pair index for DL and UL indications in TCI state, wherein a lowest beam pair includes the DL or UL common beam associated with the indicated common beam pair.

37. The method of claim 20, wherein when the method is performed in the split common beam indication mode, when the UE is configured with a plurality of TCI states, when the common beam does not exist in an indicated TCI state, and if neither an indicated DL beam nor an indicated UL beam of the indicated beam pair is a DL common beam nor an UL common beam, the UE performs the DL reception and the UL transmission using a most recently indicated common beam before a scheduling time.

38. The method of claim 20, wherein when the method is performed in the split common beam indication mode, when the UE configures a plurality of TCI states, when the common beam does not exist in an indicated TCI state, and if a DL beam or an UL beam of an indicated common beam pair is the common beam, the UE performs the DL reception and the UL transmission using a most recently indicated common beam before a scheduling time, wherein the indicated common beam includes the DL or UL common beam related to the indicated common beam pair for the scheduling time.

39. The method of claim 20, wherein the UE uses a first type of common beam configured for the DL reception and the UL transmission in the multi-beam operation and a second type of common beam configured for only the DL reception or the UL transmission in the multi-beam operation when the method is performed in the hybrid common beam indication mode.

40. The method of claim 39, wherein one or more RSs configured in one or more TCLs provide the first type of common beam and the second type of common beam.

41. The method of claim 39 or 40, wherein when the RS is associated with a plurality of K DL beams, L UL beams, S beams are applied to the DL reception and UL transmission included in the TCI state, the RS is configured to indicate whether K times L plus S beam pairs include one or more common beams.

42. The method of any one of claims 39 to 41, wherein the first type of common beam and the second type of common beam have different priorities.

43. The method of claim 42, wherein the first type of common beam has a higher priority than the second type of common beam.

44. The method of claim 42 wherein when the common beam in the TCI state is not present, the first type of common beam and the second type of common beam with higher priority configuration contained in the TCI state indicated by a most recent scheduling time are treated as the common beam.

45. The method of claim 42, wherein the base station configures a time window for the UE for distinguishing whether the common beam or the common beam pair is valid.

46. The method of claim 42, wherein if there is not only the first type of common beam within a window of time, the UE uses the common beam with the lowest index in the TCI state for the DL reception and the UL transmission in the multi-beam operation; and/or if only the second kind of common beam is included within the window time, the UE uses the common beam with the lowest beam pair index for the DL reception and the UL transmission in the multi-beam operation in the TCI state.

47. The method of claim 20, wherein K times L beam pairs are obtained by combining K DL beams associated with a plurality of DL RSs and L UL beams associated with a plurality of UL RSs, and K times L plus S beams/pairs are available for the DL reception and the UL transmission in total, when the method is performed in the hybrid common beam indication mode.

48. The method of claim 20 wherein when the method is performed in the hybrid common beam indication mode, if there is a selected beam, indexed from a first beam to a s-th beam, the UE measures the beam with the RS, providing the common beam only for the DL reception or the UL transmission; and/or if there is a selected beam having an index from a first beam pair to K times an L-th beam pair, the UE uses the RS to measure the beam, providing the common beam for the DL reception and the UL transmission.

49. The method of claim 20, wherein when the method is performed in the default common beam indication mode, the UE uses one or more default common beams as the one or more common beams when DL and UL default beams are aligned.

50. The method of claim 49, wherein the one or more default common beams comprise a most recent common beam having a lowest index contained in one of the scheduled times.

51. A method for a base station to perform common beam determination, comprising:

the base station configures one or more Transmission Configuration Indication (TCI) states to User Equipment (UE), wherein the one or more TCI states comprise one or more Reference Signals (RS);

the base station configures one or more beams to the UE, wherein the one or more beams are for multi-beam operation;

the base station identifying one or more common beams from the one or more beams according to the one or more RSs; and

the base station uses the one or more common beams for downlink DL reception and uplink UL transmission in the multi-beam operation.

52. The method of claim 51, wherein the one or more common beams are indicated according to the one or more RSs associated with the one or more beams.

53. The method of claim 51 or 52, wherein the TCI state of the base station configuration is only one.

54. The method of claim 53, wherein when there is only one RS in one TCI state, the RS is associated with the common beam for both the DL reception and/or the UL transmission in the multi-beam operation.

55. The method of claim 54, wherein the RS comprises DL RS and/or UL RS.

56. The method of claim 55, wherein the DL RS comprises channel state information CSIRS.

57. The method of claim 55, wherein the UL RS comprises a sounding reference signal, SRS.

58. The method according to any of claims 53 to 57, characterized in that radio resource control, RRC, signaling and medium access control, MAC, control element, CE, signaling are used to indicate the common beam.

59. The method of claim 53 wherein the one TCI state is activated by MAC CE signaling and a downlink control information, DCI, field is used to indicate a beam in one TCL state.

60. The method of claim 59, wherein when the indication beam in the one TCI state is not the common beam, and if there are other common beams associated with the RS in the TCI state, the UE uses the common beam with a lowest index in the TCI state for the DL reception and the UL transmission in the multi-beam operation.

61. The method of claim 60, wherein the UE uses the same common beam for the DL reception and the UL transmission in the multi-beam operation when the method is performed in a joint common beam indication mode.

62. The method of claim 61, wherein the base station identifying the one or more common beams from the one or more beams based on the one or more RSs comprises:

the base station identifies the one or more common beams from the beams according to the mapping of the beams to the RSs.

63. The method of claim 61 or 62, wherein the RS comprises parameters comprising at least one of:

a number of bits; or alternatively

The time slot of the UL signal received by the base station.

64. The method according to any one of claims 61 to 63, wherein the base station determines the mapping between the beams and the RSs by means of system information.

65. The method of any one of claims 62-64, wherein the base station identifying the one or more common beams from the beams according to the mapping of the beams to the RSs, comprises:

The base station receives beam measurement of the beam according to the mapping between the beam and the RS sent by the UE; and

the base station transmits a first indication of the one or more common beams to the UE, wherein the first indication of the one or more common beams includes a first selection of the one or more common beams by the base station according to the beam measurements.

66. The method of any one of claims 62-65, wherein the base station identifying the one or more common beams from the beams according to the mapping of the beams to the RSs, comprises:

the base station receiving a UL RS configured in the TCI state from the UE;

the base station measures UL RS from the UE; and

the base station transmits a second indication of the one or more common beams to the UE, wherein the second indication of the one or more common beams includes a second selection of the one or more common beams by the base station according to the UL RS.

67. The method of claim 66, wherein the one or more common beams depend on the UL RS associated, wherein the UL RS is the most recently received signal by the base station.

68. The method according to any one of claims 71-77, wherein the TCI state is activated by MAC CE signaling, and wherein an application downlink control information, DCI, field indicates that the one or more beams are in the one or more TCI states for a scheduled time.

69. The method of claim 68, wherein the UE uses the most recently indicated common beam for the DL reception and the UL transmission prior to the scheduled time in the multi-beam operation when one or more indicated beams in the one or more TCI states within the scheduled time are not the one or more common beams.

70. The method of any one of claims 51 to 69, wherein the method is performed in a joint common beam indication mode, a separate common beam indication mode, a hybrid common beam indication mode, or a default common beam indication mode.

71. The method of claim 70, wherein when the method is performed in the joint common beam indication mode, the UE uses the same common beam for the DL reception and the UL transmission in the multi-beam operation.

72. The method of claim 70 wherein for the joint co-beam indication scheme, both the DL reception and the UL transmission are indicated by only one common beam, the RS being associated with the common beam for both the DL reception and the UL transmission when only one RS is in a single TCI state.

73. The method of claim 72, wherein the RS is the DL RS or the UL RS.

74. The method of claim 70 wherein for the joint common beam indication, a combination of K beams associated with a flag is used to identify the common beam, wherein K is greater than 1.

75. The method of claim 74 wherein if a few of the K beams are the common beam, determining the common beam is performed using a flag value corresponding to each beam.

76. The method of claim 75, wherein if the DL RS provides the common beam, the base station selects a beam associated with the number of bits in the flag with reporting CSI from the UE, and if UL RS provides a common beam, the base station selects a beam associated with the number of bits in a flag with SRS from the UE, the selected beam being dependent on an associated uplink signal received at the base station in a most recently received signal including the reporting CSI or the SRS, a combination of K beams and a flag being used to identify whether the indicated beam is the common beam.

77. The method of claim 70, wherein for the joint common beam indication scheme, each beam is used for one slot unit, the base station selects the beam by the most recently received signal including reporting CSI or SRS, each signal received by the base station corresponds to one slot, and whether the selected beam is the common beam is identified by a correspondence of the slot to the beam.

78. The method of claim 70, wherein the UE applies separate common beams for the DL reception and the UL transmission, respectively, in the multi-beam operation when the method is performed in the split common beam indication mode.

79. The method of claim 78, wherein the one or more RSs of M TCIs provide quasi-co-located QCL hypotheses for the DL reception, the one or more RSs of N TCIs provide spatial filters for the UL transmission, and one or more candidate common beams for the DL reception and the UL transmission are contained in the M TCIs and the N TCIs, respectively, where M is greater than or equal to 1 and N is greater than or equal to 1.

80. The method of claim 78 or 79, wherein for the DL reception or the UL transmission, when there is only one TCI state, TCL state includes only one RS to provide a QCL assumption for the DL reception or the spatial filter for the UL transmission, the beam associated with the RS being the common beam for the DL reception or the UL transmission in the multi-beam operation.

81. The method of claim 78 or 79, wherein when the RS is associated with a plurality of K DL beams and L UL beams contained in the TCI state, the RS is configured to indicate whether K x L beam pairs include the one or more common beams.

82. The method of claim 70, wherein when the method is performed in the split common beam indication mode and when only one TCI state contains only one RS providing a reference for QCL or the spatial filter, the beam associated with the RS is the common beam for the DL reception or the UL transmission.

83. The method of claim 70 wherein when the method is performed in the split common beam indication mode and when the base station performs beam scanning, the UE performs beam measurements, after measuring the beams, the UE transmits the UL RS to the base station at a slot position associated with the measured beams, the base station measures the UL RS and selects the best UL beam to obtain a beam pair.

84. The method of claim 70, wherein when the method is performed in the split common beam indication mode and there is only one TCI state, both DL beams associated with DL RSs and UL beams associated with UL RSs are configured in the TCI state.

85. The method of claim 70, wherein when the method is performed in the split common beam indication mode and only one TCI state, and if neither the indicated DL beam nor the indicated UL beam of the indicated beam pair is a DL common beam and a UL common beam, the UE uses the common beam with a lowest beam pair index in the TCI state for the DL reception and the UL transmission in the multi-beam operation.

86. The method of claim 70, wherein when the method is performed in the split common beam indication mode and only one TCI state, if an indicated beam pair is not the common beam but an indicated DL beam or an indicated UL beam of the indicated beam pair is a DL common beam or an UL common beam, the UE uses the common beam with a lowest beam pair index in TCI state for DL and UL indications, wherein a lowest beam pair includes the DL or UL common beam associated with the indicated common beam pair.

87. The method of claim 70, wherein when the method is performed in the split common beam indication mode, when the UE is configured with a plurality of TCI states, when the common beam does not exist in an indicated TCI state, and if neither an indicated DL beam nor an indicated UL beam of the indicated beam pair is a DL common beam nor an UL common beam, the UE performs the DL reception and the UL transmission using a most recently indicated common beam before a scheduling time.

88. The method of claim 70, wherein when the method is performed in the split common beam indication mode, when the UE configures a plurality of TCI states, when the common beam does not exist in an indicated TCI state, and if a DL beam or an UL beam of an indicated common beam pair is the common beam, the UE performs the DL reception and the UL transmission using a most recently indicated common beam before a scheduling time, wherein the indicated common beam includes the DL or UL common beam related to the indicated common beam pair for the scheduling time.

89. The method of claim 70, wherein when the method is performed in the hybrid common beam indication mode, the UE uses a first type of common beam configured for the DL reception and the UL transmission in the multi-beam operation and a second type of common beam configured for only the DL reception or the UL transmission in the multi-beam operation.

90. The method of claim 89, wherein one or more RSs configured in one or more TCLs provide the first type of common beam and the second type of common beam.

91. The method of claim 89 or 90, wherein when the RS is associated with a plurality of K DL beams, L UL beams, S beams are applied to the DL reception and UL transmission included in the TCI state, the RS is configured to indicate whether K times L plus S beam pairs include one or more common beams.

92. The method of any one of claims 89-91, wherein the first type of common beam and the second type of common beam have different priorities.

93. The method of claim 92 wherein the first type of common beam has a higher priority than the second type of common beam.

94. The method of claim 92 wherein the first type of common beam and the second type of common beam that are configured to be higher priority contained in the TCI state of a most recent scheduled time indication are treated as the common beam when the common beam in the TCI state is not present.

95. The method of claim 92 wherein the base station configures a time window for the UE for distinguishing whether the common beam or the common beam pair is active.

96. The method of claim 92 wherein if there is not only the first type of common beam within a window of time, the UE uses the common beam with the lowest index in the TCI state for the DL reception and the UL transmission in the multi-beam operation; and/or if only the second kind of common beam is included within the window time, the UE uses the common beam with the lowest beam pair index for the DL reception and the UL transmission in the multi-beam operation in the TCI state.

97. The method of claim 70, wherein K times L beam pairs are obtained by combining K DL beams associated with a plurality of DL RSs and L UL beams associated with a plurality of UL RSs, and K times L plus S beams/pairs are available for the DL reception and the UL transmission in total, when the method is performed in the hybrid common beam indication mode.

98. The method of claim 70 wherein when the method is performed in the hybrid common beam indication mode, if there is a selected beam whose index is from a first beam to a s-th beam, the UE measures the beam with the RS, providing only the common beam for the DL reception or the UL transmission; and/or if there is a selected beam having an index from a first beam pair to K times an L-th beam pair, the UE uses the RS to measure the beam, providing the common beam for the DL reception and the UL transmission.

99. The method of claim 70, wherein when the method is performed in the default common beam indication mode, the UE uses one or more default common beams as the one or more common beams when DL and UL default beams are aligned.

100. The method of claim 99, wherein the one or more default common beams comprise a most recent common beam with a lowest index contained in one of the scheduled times.

101. A user equipment, UE, for common beam determination, comprising:

a memory;

a transceiver; and

a processor is coupled to the memory and the transceiver;

wherein the processor is configured to perform the method of any one of claims 1 to 50.

102. A base station for common beam determination, comprising:

a memory;

a transceiver; and

a processor is coupled to the memory and the transceiver;

wherein the processor is configured to perform the method of any one of claims 51 to 100.

103. A non-transitory machine-readable storage medium having instructions stored thereon, which when executed by a computer, cause the computer to perform the method of any of claims 1 to 100.

104. A chip, comprising:

a processor configured to invoke and run a computer program stored in a memory to cause a device on which the chip is installed to perform the method of any of claims 1 to 100.

105. A computer readable storage medium, characterized in that a computer program is stored, wherein the computer program causes a computer to perform the method of any one of claims 1 to 100.

106. A computer program product comprising a computer program, wherein the computer program causes a computer to perform the method of any one of claims 1 to 100.

107. A computer program, characterized in that the computer program causes a computer to perform the method according to any one of claims 1 to 100.