Apparatus and method for beam management in wireless communication system

Abstract

A user equipment and a base station and methods performed thereby are disclosed. A method performed by a user equipment includes receiving, from a base station, a radio resource control (RRC) message including first information about a semi-persistent channel state information (CSI)-reference signal (RS) configuration; receiving, from the base station, an RRC message including second information about an aperiodic CSI-RS configuration; receiving, from the base station, a semi-persistent CSI-RS based on a medium access control (MAC) control element (CE) with a periodicity for activating the semi-persistent CSI-RS configuration according to the first information; and receiving, from the base station, an aperiodic CSI-RS based on a downlink control information (DCI) for indicating the aperiodic CSI-RS configuration according to the second information.

Description

[0001] This application is a divisional application of the invention patent application filed on November 3, 2017, with application number 201780068159.9 (international application number PCT / KR2017 / 012371) and entitled "Apparatus and method for beam management in a wireless communication system". Technical Field

[0002] This disclosure relates to wireless communication. More specifically, this disclosure relates to apparatus and methods for multiple-input multiple-output (MIMO) and beam management in wireless communication systems. Background Technology

[0003] To meet the increased demand for wireless data services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "super 4G networks" or "post-LTE systems".

[0004] 5G communication systems are considered to be implemented in higher frequency millimeter-wave (mmWave) bands (such as the 60GHz band) to achieve higher data rates. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are discussed in 5G communication systems.

[0005] In addition, research and development on system network improvements is underway in 5G communication systems based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, cooperative multipoint (CoMP), and receiver interference cancellation.

[0006] In 5G systems, hybrid frequency shift keying (FSK), quadrature amplitude modulation (QAM) modulation (FQAM), and sliding window superposition coding (SWSC) have been developed as advanced coding modulation (ACM), while filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) have been developed as advanced access technologies.

[0007] The above information is presented as background information only to aid in understanding this disclosure. No determination is made, and no assertion is made, regarding whether any of the above applies to the prior art relating to this disclosure. Summary of the Invention

[0008] The aspects of this disclosure are intended to address at least the aforementioned problems and / or disadvantages, and to provide at least the following advantages. Therefore, one aspect of this disclosure is to provide an apparatus and method for beam management in a wireless communication system based on the foregoing discussion.

[0009] According to one aspect of this disclosure, a method for a base station is provided. The method includes performing signaling related to a beam reference signal (BRS) with a user equipment (UE) for beam management. The method includes sending configuration information to a terminal for beam management of the reference signal regarding the transmit (Tx) beam of the BS or the receive (Rx) beam of the terminal, and sending the reference signal to the terminal. The configuration information may include information related to the number of repetitions of the reference signal.

[0010] According to another aspect of this disclosure, a method for a terminal is provided. The method includes performing BRS-related signaling with a base station for beam management. The method includes receiving configuration information from the base station for beam management of a reference signal regarding a transmit (Tx) beam of the base station or a receive (Rx) beam of the terminal, and receiving the reference signal from the base station. The configuration information includes information related to the number of repetitions of the reference signal.

[0011] According to another aspect of this disclosure, an apparatus for a base station is provided. The apparatus includes at least one transceiver; and at least one processor connected to the at least one transceiver, wherein the at least one processor is configured to perform BRS-related signaling with a terminal for beam management. The at least one transceiver is configured to transmit configuration information to the terminal for beam management of a reference signal regarding the transmit (Tx) beam of the BS or the receive (Rx) beam of the terminal, and to transmit the reference signal to the terminal. The configuration information may include information related to the number of repetitions of the reference signal.

[0012] According to another aspect of this disclosure, an apparatus for a terminal is provided. The apparatus includes at least one transceiver; and at least one processor connected to said at least one transceiver, wherein said at least one processor is configured to perform BRS-related signaling with a base station for beam management. The at least one processor is configured to receive configuration information from the base station for beam management of reference signals regarding the transmit (Tx) beam of the BS or the receive (Rx) beam of the terminal, and to receive the reference signals from the base station. The configuration information includes information relating to the number of repetitions of the reference signals.

[0013] According to another aspect of this disclosure, a method performed by a user equipment (UE) is provided. The method includes: receiving from a base station a radio resource control (RRC) message including first information regarding a semi-persistent channel state information (CSI-reference signal) RS configuration; receiving from the base station an RRC message including second information regarding an aperiodic CSI-RS configuration; receiving semi-persistent CSI-RS from the base station based on a media access control (MAC) control element (CE) for activating the semi-persistent CSI-RS configuration using a periodicity, according to the first information; and receiving aperiodic CSI-RS from the base station based on downlink control information (DCI) for indicating the aperiodic CSI-RS configuration, according to the second information.

[0014] According to another aspect of this disclosure, a method performed by a base station (BS) is provided. The method includes: sending a radio resource control (RRC) message to a user equipment (UE) including first information regarding a semi-persistent channel state information (CSI-reference) signal (RS) configuration; sending an RRC message to the UE including second information regarding an aperiodic CSI-RS configuration; sending a semi-persistent CSI-RS to the UE based on a media access control (MAC) control element (CE) for activating the semi-persistent CSI-RS configuration using a periodicity, according to the first information; and sending an aperiodic CSI-RS to the UE based on downlink control information (DCI) for indicating the aperiodic CSI-RS configuration, according to the second information.

[0015] According to another aspect of this disclosure, a user equipment (UE) is provided. The UE includes: a transceiver; and at least one processor coupled to the transceiver and configured to: receive from a base station a radio resource control (RRC) message including first information regarding a semi-persistent channel state information (CSI-reference signal) RS configuration; receive from the base station an RRC message including second information regarding an aperiodic CSI-RS configuration; receive semi-persistent CSI-RS from the base station based on a media access control (MAC) control element (CE) for activating the semi-persistent CSI-RS configuration using a periodicity, according to the first information; and receive aperiodic CSI-RS from the base station based on downlink control information (DCI) for indicating the aperiodic CSI-RS configuration, according to the second information.

[0016] According to another aspect of this disclosure, a base station is provided. The base station includes: a transceiver; and at least one processor coupled to the transceiver and configured to: send a Radio Resource Control (RRC) message to a User Equipment (UE) including first information regarding a Semi-Persistent Channel State Information (CSI-Reference Signal) RS configuration; send an RRC message to the UE including second information regarding an Aperiodic CSI-RS configuration; based on the first information, send a Semi-Persistent CSI-RS to the UE using a periodicity based on a Media Access Control (MAC) Control Element (CE) for activating the Semi-Persistent CSI-RS configuration; and based on the second information, send an Aperiodic CSI-RS to the UE based on Downlink Control Information (DCI) for indicating the Aperiodic CSI-RS configuration.

[0017] Various embodiments of this disclosure enable operation of reference signal (RS) configurations for beam management, activation (and / or transmission) of pre-configured resources, and reporting and activation of RS configurations for which the UE is located.

[0018] The effects that can be obtained through this disclosure are not limited to those described above, and other effects not mentioned can be clearly understood by those skilled in the art to which this disclosure pertains as described below.

[0019] Other aspects, advantages, and salient features of this disclosure will become clear to those skilled in the art from the following detailed description of various embodiments of the disclosure taken in conjunction with the accompanying drawings. Attached Figure Description

[0020] The above and other aspects, features, and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0021] Figure 1 Wireless communication systems according to various embodiments of the present disclosure are shown;

[0022] Figure 2 A base station (BS) in a wireless communication system according to various embodiments of the present disclosure is shown;

[0023] Figure 3 A terminal in a wireless communication system according to various embodiments of the present disclosure is shown;

[0024] Figure 4 A communication interface in a wireless communication system according to various embodiments of the present disclosure is shown;

[0025] Figure 5A Examples of transmit / receive points (TRPs) for single-beam and multi-beam transmissions according to various embodiments of the present disclosure are shown;

[0026] Figure 5BA P-2 process based on a two-stage beam reference signal (BRS) and TRP triggering is shown, which is an example of scenario 1 according to various embodiments of this disclosure;

[0027] Figure 5C Examples of network triggering in scenario 2 according to various embodiments of this disclosure are shown;

[0028] Figure 5D Examples of user equipment (UE) triggering in scenario 2 according to various embodiments of this disclosure are shown;

[0029] Figure 5E An example of network triggering in scenario 3 according to various embodiments of the present disclosure is shown;

[0030] Figure 5F An example of network triggering in scenario 4 according to various embodiments of this disclosure is shown;

[0031] Figure 5G Examples of two-level BRS according to various embodiments of the present disclosure are shown;

[0032] Figure 5H Examples of Channel State Information-Reference Signal (CSI-RS) for P-2 according to various embodiments of the present disclosure are shown;

[0033] Figure 5I Examples of CSI-RS for P-3 according to various embodiments of the present disclosure are shown;

[0034] Figure 5J Another example of CSI-RS for P-3 according to various embodiments of this disclosure is shown; and

[0035] Figure 5K Examples of non-periodic RS for P-1 according to various embodiments of the present disclosure are shown.

[0036] Throughout the accompanying drawings, it should be noted that the same reference numerals are used to depict the same or similar elements, features, and structures. Detailed Implementation

[0037] The following description, provided with reference to the accompanying drawings, is intended to aid in a full understanding of the various embodiments of this disclosure as defined by the claims and their equivalents. It includes various specific details to aid understanding, but these are to be considered exemplary only. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of this disclosure. Additionally, descriptions of well-known functions and structures may be omitted for clarity and conciseness.

[0038] The terms and words used in the following description and claims are not limited to their literal meaning, but are used by the inventors only to enable a clear and consistent understanding of this disclosure. Therefore, it will be apparent to those skilled in the art that the following description providing various embodiments of this disclosure is for illustrative purposes only and is not intended to limit the purpose of this disclosure as defined by the appended claims and their equivalents.

[0039] It should be understood that, unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” include plural indicators. Thus, for example, a reference to “component surface” includes a reference to one or more such surfaces.

[0040] In the following description, hardware-based approaches will be used as examples to illustrate various embodiments of this disclosure. However, the various embodiments of this disclosure include techniques using both hardware and software, and therefore software-based approaches are not excluded.

[0041] In the following, this disclosure relates to apparatus and methods for beam management in wireless communication systems. Specifically, this disclosure will describe signaling for operating beams in wireless communication systems and techniques for configuring the signaling.

[0042] The signal-related terms (e.g., reference signal (RS), synchronization signal, and beam RS), terms relating to configuration, terms relating to network entities, terms relating to elements of the apparatus, etc., used in the following description are for illustrative purposes only. Therefore, this disclosure is not limited to the following terms, and other terms with equivalent technical meanings may be used.

[0043] Furthermore, various embodiments of this disclosure are described using terminology based on a certain communication standard (e.g., the 3rd Generation Partnership Project (3GPP)), but this description is for illustrative purposes only. Various embodiments of this disclosure can be readily modified and applied to other communication systems.

[0044] Figure 1 Wireless communication systems according to various embodiments of the present disclosure are shown.

[0045] refer to Figure 1 Base station (BS) 110, terminal 120, and terminal 130 are shown as part of a node using a wireless channel in a wireless communication system. Figure 1 Only one BS is shown, but another BS that is the same as or similar to BS 110 may be further included.

[0046] BS 110 is a network infrastructure that provides wireless access to terminals 120 and 130. Based on the distance at which signals can be transmitted, BS 110 has a coverage area defined as a predetermined geographical region. BS 110 can be referred to as an "Access Point (AP)," "eNodeB (eNB)," "5G Node," "Radio Point," "Transmit / Receive Point (TRP)," and "Base Station."

[0047] Each of terminals 120 and 130 is a device used by a user and performs communication with BS 110 via a wireless channel. Depending on the circumstances, at least one of terminals 120 and 130 can operate without user intervention. That is, at least one of terminals 120 and 130 is a device that performs machine-type communication (MTC) and can be carried by no user. Each of terminals 120 and 130 may be referred to as "User Equipment (UE)," "Mobile Station," "Subscriber Station," "Remote Terminal," "Wireless Terminal," or simply "User Equipment" and "Terminal."

[0048] BS 110, Terminal 120, and Terminal 130 can transmit and receive wireless signals in millimeter-wave (mmWave) bands (e.g., 28 GHz, 30 GHz, 38 GHz, and 60 GHz). To improve channel gain, BS 110, Terminal 120, and Terminal 130 can perform beamforming. Beamforming can include transmit beamforming and receive beamforming. That is, BS 110, Terminal 120, and Terminal 130 can assign directivity to transmit and receive signals. To this end, BS 110 and Terminals 120 and 130 can select serving beams 112, 113, 121, and 131 through a beam search process or a beam management process. Then, communication can be performed using resources with quasi-co-located relationships to the resources carrying serving beams 112, 113, 121, and 131.

[0049] If the large-scale characteristics of the channel transmitting symbols at the first antenna port can be inferred from the channel transmitting symbols at the second antenna port, then the first and second antenna ports are considered quasi-co-located. Large-scale characteristics may include one or more of delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial Rx parameters.

[0050] Figure 2 A BS in a wireless communication system according to various embodiments of the present disclosure is shown.

[0051] Figure 2The structure illustrated herein can be understood as the structure of BS 110. The terms “-module,” “-unit,” or “-device” used below may refer to a unit for performing at least one function or operation and may be implemented in hardware, software, or a combination of hardware and software.

[0052] refer to Figure 2 The BS may include a wireless communication interface 210, a backhaul communication interface 220, a storage unit 230 (e.g., a memory), and a controller 240 (e.g., at least one processor).

[0053] The wireless communication interface 210 performs functions for transmitting and receiving signals via a wireless channel. For example, the wireless communication interface 210 can perform conversion functions between baseband signals and bitstreams according to the system's physical layer standard. For example, in data transmission, the wireless communication interface 210 generates complex symbols by encoding and modulating the transmitted bitstream. Furthermore, in data reception, the wireless communication interface 210 reconstructs the received bitstream by demodulating and decoding the baseband signal.

[0054] Furthermore, the wireless communication interface 210 up-converts the baseband signal to a radio frequency (RF) band signal, transmits the converted signal through an antenna, and then down-converts the RF band signal received through the antenna back to a baseband signal. For this purpose, the wireless communication interface 210 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and so on. In addition, the wireless communication interface 210 may include multiple transmit / receive paths. Furthermore, the wireless communication interface 210 may include at least one antenna array composed of multiple antenna elements.

[0055] On the hardware side, the wireless communication interface 210 may include digital units and analog units, and the analog units may include multiple sub-units depending on the operating power, operating frequency, etc. The digital units may be implemented as at least one processor (e.g., a digital signal processor (DSP)).

[0056] Wireless communication interface 210 transmits and receives signals as described above. Therefore, wireless communication interface 210 can be referred to as a "transmitter," a "receiver," or a "transceiver." Furthermore, in the following description, "transmission and reception performed via a wireless channel" can be used to mean having the meaning of including the processes performed by wireless communication interface 210 as described above.

[0057] The backhaul communication interface 220 provides an interface for performing communication with other nodes within the network. That is, the backhaul communication interface 220 converts bit streams sent from a BS to another node (e.g., another access node, another BS, a higher node, or the core network) into physical signals and converts physical signals received from another node into bit streams.

[0058] Storage unit 230 stores basic programs, applications, and data such as setup information for the operation of BS 110. Storage unit 230 may include volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Furthermore, storage unit 230 provides stored data in response to requests from controller 240.

[0059] Controller 240 controls the general operation of the BS. For example, controller 240 sends and receives signals via wireless communication interface 210 or backhaul communication interface 220. Furthermore, controller 240 records data in storage unit 230 and reads the recorded data. Controller 240 can perform the functions of the protocol stack required by the communication standard. According to another implementation, the protocol stack may be included in wireless communication interface 210. According to various embodiments of this disclosure, controller 240 can control the base station to perform operations according to various embodiments of this disclosure (i.e., signal configuration, resource settings, reporting settings).

[0060] Figure 3 A terminal in a wireless communication system according to various embodiments of the present disclosure is shown.

[0061] Figure 3 The structure illustrated herein can be understood as the structure of terminal 120 or terminal 130. The terms “-module,” “-unit,” or “-device” used below may refer to a unit for processing at least one function or operation, and may be implemented in hardware, software, or a combination of hardware and software.

[0062] refer to Figure 3 The terminal 120 includes a communication interface 310, a storage unit 320 (e.g., a memory), and a controller 330 (e.g., at least one processor).

[0063] Communication interface 310 performs functions for transmitting / receiving signals via a wireless channel. For example, communication interface 310 performs conversion between baseband signals and bitstreams according to the system's physical layer standard. For instance, in data transmission, communication interface 310 generates complex symbols by encoding and modulating the transmitted bitstream. Furthermore, in data reception, communication interface 310 reconstructs the received bitstream by demodulating and decoding the baseband signal. Additionally, communication interface 310 up-converts the baseband signal to an RF band signal, transmits the converted signal through an antenna, and then down-converts the RF band signal received through the antenna back to a baseband signal. For example, communication interface 310 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC.

[0064] Furthermore, the communication interface 310 may include multiple transmit / receive paths. Additionally, the communication interface 310 may include at least one antenna array consisting of multiple antenna elements. On the hardware side, the wireless communication interface 210 may include digital and analog circuitry (e.g., a radio frequency integrated circuit (RFIC)). The digital and analog circuitry may be implemented in a single package. The digital circuitry may be implemented as at least one processor (e.g., a DSP). The communication interface 310 may include multiple RF chains. The communication interface 310 may perform beamforming.

[0065] As described above, communication interface 310 transmits and receives signals. Therefore, communication interface 310 can be referred to as a "transmitter," a "receiver," or a "transceiver." Furthermore, in the following description, transmission and reception performed via a wireless channel are used to mean having the processing performed by communication interface 310 as described above.

[0066] Storage unit 320 stores basic programs, applications, and data such as settings information for the operation of terminal 120. Storage unit 320 may include volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Furthermore, storage unit 320 provides stored data in response to requests from controller 330.

[0067] Controller 330 controls the general operation of terminal 120. For example, controller 330 sends and receives signals through communication interface 310. Furthermore, controller 330 records data in storage unit 320 and reads the recorded data. Controller 330 can perform the functions of the protocol stack required by the communication standard. According to another implementation, the protocol stack may be included in communication interface 310. For this purpose, controller 330 may include at least one processor or microprocessor, or may act as part of a processor. Furthermore, communication interface 310 or part of controller 330 may be referred to as a communication processor (CP). According to various embodiments of this disclosure, controller 330 can control the terminal to perform operations (i.e., signal measurement, reporting measurement results) according to various embodiments of this disclosure.

[0068] Figure 4 A communication interface in a wireless communication system according to various embodiments of the present disclosure is shown.

[0069] Figure 4 It shows Figure 2 Wireless communication interface 210 or Figure 3 A detailed configuration example of the communication interface 310. More specifically, Figure 4 The element used to perform beamforming is shown as follows. Figure 2 Communication interface 210 or Figure 3 It is part of the communication interface 310.

[0070] refer to Figure 4 The communication interface 210 or 310 includes encoding and circuitry 402, digital circuitry 404, multiple transmission paths 406-1 to 406-N, and analog circuitry 408.

[0071] Encoding and circuitry 402 performs channel coding. For channel coding, at least one of low-density parity-check (LDPC) codes, convolutional codes, and polar codes can be used. Encoding and circuitry 402 generates modulation symbols by performing constellation mapping.

[0072] Digital circuit 404 performs beamforming on a digital signal (e.g., a modulation symbol). To do this, digital circuit 404 multiplies the modulation symbol by a beamforming weight. The beamforming weight can be used to change the magnitude and phase of the signal and can be referred to as a "precoding matrix" or "precoder." Digital circuit 404 outputs the digitally beamformed modulation symbol to multiple transmission paths 406-1 to 406-N. At this point, according to a multiple-input multiple-output (MIMO) transmission scheme, the modulation symbol can be multiplexed, or the same modulation symbol can be provided to multiple transmission paths 406-1 to 406-N.

[0073] Multiple transmission paths 406-1 to 406-N convert the digital signals generated by digital beamforming into analog signals. For this purpose, each of the multiple transmission paths 406-1 to 406-N may include an inverse fast Fourier transform (IFFT) calculation unit, a cyclic prefix (CP) insertion unit, a DAC, and an up-conversion unit. The CP insertion unit is used for orthogonal frequency division multiplexing (OFDM) schemes and can be omitted when another physical layer scheme (e.g., filter bank multicarrier (FBMC)) is applied. That is, the multiple transmission paths 406-1 to 406-N provide independent signal processing for the multiple streams generated by digital beamforming. However, depending on the implementation, some components of the multiple transmission paths 406-1 to 406-N may be shared.

[0074] Analog circuit 408 performs beamforming on the analog signal. To do this, digital circuit 404 multiplies the analog signal by a beamforming weighting value. The beamforming weighting value is used to change the magnitude and phase of the signal. More specifically, analog circuit 408 can be configured in various ways depending on the connection structure between the multiple transmission paths 406-1 to 406-N and the antenna. For example, each of the multiple transmission paths 406-1 to 406-N can be connected to an antenna array. In another example, the multiple transmission paths 406-1 to 406-N can be connected to an antenna array. In yet another example, the multiple transmission paths 406-1 to 406-N can be adaptively connected to an antenna array, or they can be connected to two or more antenna arrays.

[0075] Various embodiments of this disclosure generally relate to wireless communication, and more specifically, to base station / UE (e.g., TRP / UE) operation for P-1 / P-2 / P-3, which corresponds to beam management procedures in the field of MIMO / beam management.

[0076] Various embodiments of this disclosure relate to P-1 / P-2 / P-3 beam management procedures and signaling (e.g., RS) used therein in multi-beam systems. This disclosure may include operations of RS configuration for beam management, activation (and / or transmission) of pre-configured resources, and reporting and activation of RS configurations by the UE for those resources.

[0077] In the following, before describing this disclosure in detail, the meanings of the terms used in this disclosure will be described. Reference will be made to the Full Dimensional (FD)-MIMO Research Project (SI) (TR36.897) for descriptions 1) to 3).

[0078] 1) Hybrid Beamforming (BF): An architecture for dynamically changing the virtualization weights of transceiver units (TXRUs) over time (i.e., simulating the phase and amplitude of BF).

[0079] 2) Digital BF: Refers to the case where static TXRU virtualization weights (one or more) are executed. However, digital BF can also represent the form in which the digitally formed beam changes over time.

[0080] 3) Single beam scheme: This means that the beam generated by the base station is wide enough and the service area is covered without scanning.

[0081] 4) Multi-beam: This refers to a situation where the beam generated by the base station is narrow and the service area needs to be scanned to cover the area.

[0082] 5) Beam scanning: This refers to the action of adjusting the beam and transmitting signals in all directions of the cell during a predetermined time period to prevent angular coverage holes during beam generation (see [link]). Figure 1 ).

[0083] Figure 5A Examples of single-beam and multi-beam transmission TRPs according to various embodiments of this disclosure are shown.

[0084] 6) Non-zero power channel state information-reference signal CSI-RS (NZP CSI-RS): In this disclosure, it refers to the RS used for beam measurement. The RS may be UE-specific. “NZP” is used to distinguish NZP CSI-RS from zero power CSI-RS (ZP CSI-RS).

[0085] 7) ZP CSI-RS: When relevant resources (e.g., frequency / time resources) in the UE's data reception include NZP CSI-RS resources allocated to different UEs, the base station (e.g., TRP) notifies the UE to help the UE exclude relevant resources and decode the data.

[0086] 8) Beam management procedure P-1: This describes the procedure for associating the base station's transmit beam (e.g., TRP Tx beam) with the UE's receive beam (e.g., UE Rx beam).

[0087] 9) Beam management procedure P-2: This describes the procedure used to improve the transmit beam of a base station (e.g., TRP Tx beam).

[0088] 10) Beam management procedure P-3: This indicates the procedure used to improve the UE's receive beam (e.g., UE Rx beam).

[0089] 11) Next-Generation Node B (gNB): May include a single TRP or multiple TRPs. In the following, the term "base station" as used in this disclosure may refer to a single gNB, a single TRP, or a single TRP cluster (i.e., a cluster comprising multiple TRPs). A gNB may exist within a cell. A cell can be identified as a single-beam transmission cell when each of the multiple TRPs or TRP clusters within each cell operates as a single beam. That is, for example, when a single TRP exists within a cell, this can be represented as TRP = TRP cluster = gNB = cell.

[0090] 12)UE: Refers to User Equipment.

[0091] This disclosure proposes various signaling use cases for the aforementioned P-1 / P-2 / P-3 beam management, and proposes base station / UE operations based on these use cases. For beam management, the scenarios shown in Table 1 below can be implemented.

[0092] [Table 1]

[0093] Table 1 (Various Beam-Managed RS Scenarios)

[0094]

[0095] In Table 1, cell-specific RS configurations can be performed based on the following:

[0096] Alt (Alternative Method) 1: System Information

[0097] Alt 2: Message (Msg) 4 of the Random Access Channel (RACH) procedure, and

[0098] Alt 3: Physical Downlink Shared Channel (PDSCH) transmitted after RACH. In Table 1, UE-specific RS can be configured via UE-specific Radio Resource Control (RRC) signaling. Through RS, the UE can measure quality, such as the signal strength of the beams used for beam management (i.e., Reference Signal Received Power (RSRP)). The UE can transmit the ID of one or more preferred beams and / or the corresponding RSRP as a report of the measurement. In the following text, the term "UE report" may refer to the UE's operation of feeding back beam IDs and / or RSRPs.

[0099] According to various embodiments of this disclosure, UE-specific RSs can be configured differently. For example, UE-specific RSs can be periodic, semi-static, or aperiodic CSI-RSs. Aperiodic UE-specific RSs can be configured via RRC signaling, and then CSI-RS transmission can be activated via downlink control information (DCI) / media access control (MAC)-control element (CE), etc. Semi-static CSI-RSs refer to a type that periodically transmits semi-static CSI-RSs when the configured CSI-RS becomes "on" in the DCI / MAC-CE, and does not transmit semi-static CSI-RSs when the configured CSI-RS becomes "off" in the DCI / MAC-CE.

[0100] In the following text, for ease of description, the cell-specific RS and UE-specific RS used for beam management shown in Table 1 will be referred to as “Band RS (BRS)” and “CSI-RS”, respectively.

[0101] In the following sections, the operations for each base station / UE in each scenario will be defined. However, the operations described below are examples of various embodiments according to this disclosure, and therefore, the embodiments of this disclosure are not limited to the base station / UE operations described below.

[0102] [Scene 1]

[0103] Step 1) Configure BRS

[0104] Alt 1: Configure and use a single BRS for P-1 / P-2 / P-3 and

[0105] Alt 2: Configure and utilize the BRS for P-1 (i.e., BRS1) and the BRS for P-2 (i.e., BRS2);

[0106] Step 2) If necessary, P-2 is triggered by TRP or UE;

[0107] Alt 1: Network Triggered: Sends a request to the UE via DCI or MAC-CE to report information about P-2, and

[0108] Alt 2: UE Triggered: The UE reports relevant information when it recognizes that such information is needed; and

[0109] Step 3) UE reports to P-2.

[0110] Figure 5B A P-2 process based on two-level BRS and TRP triggering is shown, which is an example of scenario 1 according to various embodiments of this disclosure. Figure 5B The operation of TRP-UE in step 1)-Alt 2 and P-2 triggered by TRP relative to scenario 1 are shown.

[0111] In scenario 1, P-3 can be resolved through UE implementation issues.

[0112] [Scene 2]

[0113] Step 1) Configure the BRS to be used when P-1 is in operation;

[0114] Step 2) The UE reports to P-1;

[0115] Step 3) For P-2 / P-3, configure NZP CSI-RS and ZP CSI-RS via RRC signaling;

[0116] Step 4) Trigger P-2 or P-3 by TRP or UE if necessary: ​​In particular, when semi-persistent CSI-RS and aperiodic CSI-RS are configured,

[0117] Alt 1: Network Triggered: The base station can specify CSI-RS resources via DCI or MAC-CE. The base station can request the UE to report information about P-2 or P-3.

[0118] Figure 5C An example of network triggering in scenario 2 according to various embodiments of this disclosure is shown.

[0119] Alt 2: UE Triggered: As needed, the UE may request the transmission of CSI-RS. The base station then operates in the same / similar manner as Alt 1.

[0120] Figure 5D An example of UE triggering in scenario 2 according to various embodiments of this disclosure is shown.

[0121] Step 5) The UE reports for P-2 or P-3.

[0122] Based on the TRP-UE operation in scenario 2 Figure 5C and 5D As shown in the image.

[0123] [Scene 3]

[0124] Step 1) Configure the NZP CSI-RS and ZP CSI-RS for P-1 / P-2 / P-3 operations via RRC signaling;

[0125] Step 2) The UE reports to P-1;

[0126] Step 3) Trigger P-2 or P-3 by TRP or UE if necessary: ​​In particular, when semi-persistent CSI-RS and aperiodic CSI-RS are configured,

[0127] Alt 1: Network Triggered: The network (i.e., the base station, gNB) allocates CSI-RS resources via DCI or MAC-CE and requests the UE to report information about P-2 or P-3, and

[0128] Alt 2: UE Triggered: The UE requests the transmission of the relevant CSI-RS when it recognizes a need for it. Subsequent operations by the base station are the same as those of Alt 1; and

[0129] Step 4) The UE reports for P-2 or P-3.

[0130] Based on the TRP-UE operation in scenario 3 Figure 5E As shown in the image.

[0131] Figure 5E An example of network triggering in scenario 3 according to various embodiments of this disclosure is shown.

[0132] [Scene 4]

[0133] Step 1) UE synthesized beam selection and reporting;

[0134] Step 2) Configure NZP CSI-RS and / or ZP CSI-RS for P-1 / P-2 / P-3 operations via RRC signaling.

[0135] According to various embodiments of this disclosure, the NZP CSI-RS for P-1 can depend on the number of synthesized beams. That is, when comparing BRS1 of scenario 1 with CSI-RS of scenario 3, a relatively simplified design can be used to operate the CSI-RS for P-1;

[0136] Step 3) The UE reports to P-1;

[0137] Step 4) If necessary, TRP or UE will trigger P-2 or P-3.

[0138] In particular, when semi-persistent CSI-RS and aperiodic CSI-RS are configured,

[0139] Alt 1: Network Triggered: The network (i.e., the base station, gNB) specifies CSI-RS resources via DCI or MAC-CE and requests the UE to report information about P-2 or P-3, and

[0140] Alt 2: UE Triggered: When the UE recognizes a need for the relevant CSI-RS, it requests the transmission of the relevant CSI-RS. Subsequent operations by the base station are the same as those of Alt 1.

[0141] Step 5) The UE reports for P-2 or P-3;

[0142] Step 6) When the index of the preferred synthetic beam of the UE changes, the UE reports the changed index information of the preferred synthetic beam to the base station.

[0143] Step 7) The base station applies the modified beam to the relevant CSI-RS resources of P-1; and

[0144] Step 8) UE reports that the UE performs P-1.

[0145] Based on the TRP-UE operation in scenario 4 Figure 5F As shown in the image.

[0146] Figure 5F An example of network triggering in scenario 4 according to various embodiments of this disclosure is shown.

[0147] In scenario 4, a composite beam can refer to a wide beam formed by combining multiple narrow beams used in the downlink before the UE associates the base station's transmit beam (e.g., TRP Tx beam) with the UE's receive beam (e.g., UE Rx beam). According to various embodiments of this disclosure, composite beams can be used to transmit synchronization and physical broadcast channels (PBCH), etc.

[0148] Next, various and detailed embodiments of this disclosure in one or more scenarios will be described.

[0149] [Two-level BRS: Applicable to Scenario 1]

[0150] When cell-specific RS BRS1 is used for P-1 and P-3 and BRS2 is used for P-2 and P-3, BRS1 and BRS2 can be configured via the same or different physical channels. For example, BRS1 can be configured via the Master Information Block (MIB), and then it can be configured whether BRS2 is configured via the System Information Block (SIB) or whether BRS2 is used in the SIB. Essentially, only BRS1 is available for handover measurements. BRS2 configuration information may include the following parameters, and an embodiment of the BRS2 configuration information is described in... Figure 5G As shown in the image.

[0151] Figure 5G Examples of two-level BRS according to various embodiments of the present disclosure are shown.

[0152] 1. The number of refinement symbols (the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols in BRS2), and

[0153] 2. Cycle.

[0154] [Configurable cell-specific RS: Applicable to scenario 1 / 2]

[0155] According to various embodiments of this disclosure, the system can determine that the period of a cell-specific RS defined as performing P-1 is flexible. For example, when the number of UEs in the connected state in the cell is small, the period of the relevant RS can be kept relatively long. The period of the relevant RS can be configured through synchronization and system information. When configuring the period of the relevant RS through synchronization, the period configuration can be distinguished by the sequence of the primary synchronization signal (PSS), secondary synchronization signal (SSS), or extended synchronization signal (ESS).

[0156] [Configuration of UE-specific RS for beam management based on UE capabilities: applicable to scenarios 2 / 3 / 4]

[0157] According to various embodiments of this disclosure, the UE can request the base station to configure the RS. That is, the RS for P-3 can be configured based on the UE's request. The UE can send information related to the number of beams to the base station. For example, to refine the received beam, the UE can notify the TRP of information related to the number of Rx beams used for training. This information can be used to determine the number of repetitive transmissions to the UE's RS associated with a given TRP Tx beam for P-3. In other words, this information can include information on the number of repetitive transmissions for RS (e.g., CSI-RS). The information can be sent via higher-layer signaling, MAC-CE, or UCI. The number of Rx beams required for training requested by the UE can be determined based on at least one of the number of transceiver units (TXRUs) owned by the UE, whether multi-beam scanning is to be performed, and the number of beams. Various schemes can be used for the UE to send relevant information to the TRP.

[0158] Alt 1a: [Applicable to all TRP / UE-triggered scenarios] A scheme for sending relevant information via message 3 (Msg3) during the random access procedure.

[0159] Alt 2a: [Applicable to all TRP / UE-triggered scenarios] A scheme for sending relevant information through the UE capability negotiation process (e.g., UE capability information) after connection establishment, and

[0160] Alt 3a: [Applicable to UE-only triggering scenarios] A scheme to send relevant information along with P-3 during the sending of the trigger request message.

[0161] The base station can determine the number of RS repetitions (e.g., CSI-RS) based on the UE's request. For example, the base station can determine the number of CSI-RS repetitions based on information received from the UE (e.g., capability information) and can allocate resources based on the number of repetitions. Information regarding the requested number of RS repetitions associated with a given TRP TX beam, which has already been requested by the UE, can be determined by the base station (the base station controlling the TRP). The base station (the base station controlling the TRP) can accept the value already requested by the UE without making any changes based on resource availability scenarios and can determine the number of RS repetitions. Alternatively, the base station may not accept the value but can determine the number of RS repetitions according to different schemes. The number of RS repetitions associated with a given TRP TX beam of P-3, which has already been determined by the base station, can be communicated to the UE according to the following scheme (e.g., information indicating RS repetitions can be referred to as repetition information).

[0162] Alt 1b: [When the UE request information is received via Alt 1a and Alt 2a] is used to configure a method for including duplicate information during NZP / ZP CSI-RS in RRC (Reconfiguration) signaling, and

[0163] Alt 2b: [When the UE request information is received via Alt 1a, Alt 2a, and Alt 3a] When the transmission of NZP / ZP CSI-RS configured via RRC (reconfiguration) signaling is activated via DCI / MAC-CE, a method for including duplicate information in it (DCI / MAC-CE).

[0164] [NZP / ZP UE-specific RS for beam management: related to scenarios 2 / 3 / 4]

[0165] According to various embodiments of this disclosure, the configuration of the NZP CSI-RS for P-2 may include the following parameters.

[0166] 1. Number of antenna ports = Number of TRP Tx beams in a single time instance.

[0167] 2. The number of OFDM symbols used for improvement.

[0168] 3. Resource Configuration: Mode (e.g., starting OFDM symbol number within a subframe (SF), and starting subcarrier index within a resource block (RB), CSI-RS transmission frequency resources (subband or wideband), and the starting SF number within the frame, and

[0169] 4. Period: Defined only in the case of periodic CSI-RS.

[0170] According to various embodiments of this disclosure, the configuration of the NZP CSI-RS for P-3 may include the following parameters.

[0171] 1. Number of CSI-RS repetitions: This can be selected based on information regarding the requested number of RS repetitions associated with a given TRP Tx beam requested by the UE.

[0172] 2. Resource configuration: mode (e.g., starting OFDM symbol number within the SF, and starting subcarrier index within the RB), CSI-RS transmission frequency resources (subband or wideband), and starting SF number within the frame, and

[0173] 3. Period: Defined only in the case of periodic CSI-RS.

[0174] In some embodiments of this disclosure, when information about the number of repetitions of RS associated with a given TRP Tx beam for P-3 is transmitted via DCI or MAC-CE, information about the number of repetitions of CSI-RS can be excluded from the configuration of NZP CSI-RS for P-3.

[0175] In some embodiments of this disclosure, when P-2 and P-3 are configured independently, the parameters within each configuration can be configured as described above. However, in some other embodiments of this disclosure, when P-2 and P-3 are configured in the same format, the parameters for the configuration can be described as follows.

[0176] 1. Number of antenna ports = Number of TRP Tx beams in a single time instance.

[0177] 2. The number of OFDM symbols used for TRP Tx beamforming.

[0178] 3. Number of CSI-RS repetitions: Selected based on information regarding the requested number of RS repetitions associated with a given TRP Tx beam, as requested by the UE.

[0179] 4. Resource Configuration: Mode (e.g., starting OFDM symbol number within the SF, and starting subcarrier index within the RB), CSI-RS transmission frequency resources (subband or wideband), and starting SF number within the frame, and

[0180] 5. Period: Defined only in the case of periodic CSI-RS.

[0181] When P-2 and P-3 are configured in the same format, multiple CSI-RS configurations can be included in a single CSI procedure within an RRC message (each configuration can be assigned an ID). Subsequently, CSI-RS can be sent via DCI / MAC-CE using the corresponding configuration ID. The following... Figure 5H , 5I Figures 5 and 5J show examples of CSI-RS transmitted for P-2 and P-3. Figures 5H to 5J The mapping is shown on a per-RB basis. In some embodiments of this disclosure, this mapping may be repeated across all RBs in the system bandwidth (BW).

[0182] Figure 5H Examples of CSI-RS for P-2 according to various embodiments of the present disclosure are shown.

[0183] refer to Figure 5H , Figure 5H An example is shown below for configuring the parameters for CSI-RS for P-2:

[0184] 1. Number of antenna ports = 4

[0185] 2. The number of OFDM symbols used for improvement = 1, and

[0186] 3. The starting OFDM symbol number in SF is 0, and the starting subcarrier index in RB is 2.

[0187] Figure 5I Examples of CSI-RS for P-3 according to various embodiments of this disclosure are shown.

[0188] refer to Figure 5I , Figure 5I An example is shown below for configuring the parameters for CSI-RS for P-3:

[0189] 1. The number of repetitions in CSI-RS = 4, and

[0190] 2. The starting OFDM symbol number in SF is 0, and the starting subcarrier index in RB is 2.

[0191] exist Figure 5I In the illustrated embodiment, repeated RS is transmitted using consecutive symbols, but the embodiments of this disclosure are not limited thereto. In another embodiment of this disclosure, RS can be transmitted using non-consecutive symbols.

[0192] Figure 5J Another example of a CSI-RS for P-3 according to various embodiments of the present disclosure is shown.

[0193] refer to Figure 5J , Figure 5J An embodiment in which a wider subcarrier spacing is used for P-3 CSI-RS is shown, and some parameters that differ from those in the configuration described above for P-3 NZP CSI-RS are utilized. For example, the parameters are as follows:

[0194] 1. The number of CSI-RS repetitions in the OFDM symbol.

[0195] 2. The number of OFDM symbols used for repetition.

[0196] 3. Resource configuration: mode (e.g., starting OFDM symbol within SF, and starting subcarrier index within RB), CSI-RS transmission frequency resources (subband or wideband), and starting SF number within the frame, and

[0197] 4. Period: Defined only in the case of periodic CSI-RS.

[0198] By increasing the subcarrier spacing of CSI-RS, multiple CSI-RS can be transmitted during the duration of one OFDM symbol. The CSI-RS can use a subcarrier spacing extended according to the number of repetitions representing the number of CSI-RS repetitions. Alternatively, after pre-specifying the subcarrier spacing for P-3 (e.g., 4 to 10 subcarriers), the same number of CSI-RS as the corresponding sub-symbols can be used to transmit CSI-RS. For example, when the subcarrier spacing for P-3 CSI-RS is limited to a distance equal to four times the subcarrier spacing of the data:

[0199] i) When it is desired that the RS be repeated four times, use an OFDM symbol (an OFDM symbol consists of four sub-symbols) to send the CSI-RS.

[0200] ii) When it is desired that the RS be repeated eight times, two OFDM symbols are used to send the CSI-RS.

[0201] The configuration of ZP CSI-RS for P-2 and P-3 can include the following parameters.

[0202] 1. Number of antenna ports = Number of beams in a single time instance.

[0203] 2. Number of OFDM symbols: Related to the number of OFDM symbols used for TRP Tx beamforming and the number of repeating RS.

[0204] 3. The number of CSI-RS repetitions in the OFDM symbol (used only when adjusting the subcarrier spacing of the CSI-RS),

[0205] 4. Resource Configuration: Mode (e.g., starting OFDM symbol number within the SF, and starting subcarrier index within the RB), CSI-RS transmission frequency resources (subband or wideband) and starting SF number within the frame, and

[0206] 5. Period: Defined only when ZP CSI-RS is configured for periodic CSI-RS.

[0207] [Use scenarios and related procedures for two types of P-1 ((1) P-1 for typical (periodic) TRP Tx / UE Rx beam association, and (2) P-1 for scenarios where the TRP Tx / UE Rx beam needs to be changed suddenly): applicable to scenarios 1 / 2 / 3 / 4]

[0208] As an RS used to support P-1, periodic or aperiodic RS can be configured. Periodic RS can be sent for initial TRP Tx-UE Rx beam association and subsequent updates, and refers to the RS introduced above for P-1. Aperiodic RS can be sent to determine that currently associated beams are inappropriate and to anticipate a sudden change in the TRP Tx-UE Rx beams. According to various embodiments of this disclosure, aperiodic RS can be initiated by the base station of the aperiodic RS (network-based triggering) or by a request from the UE (UE-based triggering).

[0209] As an alternative (Alt) to the RS mode that can be pre-specified between the TRP and UE with a non-periodic RS for supporting P-1, there exists.

[0210] Alt 1: The base station can repeatedly transmit the RS designated for P-1 based on the value determined by the UE beam scanning capability described above. In this case, according to various embodiments of this disclosure, the RS designated for P-1 can be mapped to consecutive symbols or SFs.

[0211] Alt 2: The base station can use the RS configured for P-2 and P-3.

[0212] When the transmission of RS (i.e., the aperiodic RS for P-1) is activated via DCI / MAC-CE in relation to Alt 2, P-2 / P-3 can operate in the form of simultaneous activation of RS transmission.

[0213] Figure 5K Examples of non-periodic RS for P-1 according to various embodiments of the present disclosure are shown.

[0214] Figure 5K The operation of the TRP-UE associated with the non-periodic RS of P-1 is shown in response to the request of the UE in scenario 2.

[0215] The methods according to the claims of this disclosure or the embodiments described in the specification of this disclosure may be implemented in hardware, software, or a combination of hardware and software.

[0216] When the method is implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors within an electronic device. The one or more programs may include instructions that cause the electronic device to perform the method according to the claims of this disclosure or the embodiments described in the specification of this disclosure.

[0217] The program (software module or software) can be stored in random access memory, including flash memory, read-only memory (ROM), electrically erasable programmable ROM (EEPROM), disk storage devices, optical disc ROM (CD-ROM), digital versatile optical disc (DVD), other types of optical storage devices, or non-volatile memory such as magnetic tape cartridges. Alternatively, the program can be stored in a memory configured with some or all of such storage devices. Moreover, multiple copies of each of these memory devices can be provided.

[0218] Furthermore, the program can be stored in an attachable storage device, which can be accessed by an electronic device via a communication network such as the Internet, intranet, local area network (LAN), wireless LAN (WLAN), or storage area network (SAN), or via a communication network configured by a combination thereof. The storage device can be connected to an electronic device executing embodiments of this disclosure via an external port. Alternatively, a separate storage device on the communication network can be connected to the electronic device executing embodiments of this disclosure.

[0219] In the specific embodiments described above, the elements included in this disclosure are represented in a singular or plural form according to the proposed specific embodiments. However, the present disclosure is not limited to a single element or multiple elements, and elements expressed in a plural form may be configured as a single element or elements expressed in a singular form may be configured as multiple elements.

[0220] Although this disclosure has been shown and described with reference to various embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of this disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a user equipment (UE), the method comprising: Receive first information from the base station, the first information configuring the semi-persistent channel state information CSI-reference signal RS resources included in the radio resource control (RRC) message; Receive second information from the base station, the second information configuring the non-periodic CSI-RS resources included in the RRC message; Receive from the base station either a Media Access Control (MAC) control element (CE) for activating a semi-persistent CSI-RS resource configured by the first information or downlink control information for activating a non-periodic CSI-RS resource configured by the second information; Receive at least one CSI-RS from the base station; In the case of receiving a MAC CE: The at least one CSI-RS includes semi-persistent CSI-RS received periodically. The MAC CE includes an identifier indicating the first information, and Information regarding the periodicity is included in the first information, and In the case of receiving DCI: The at least one CSI-RS includes a non-periodic CSI-RS.

2. The method according to claim 1, in, The first and second information include resource information about CSI-RS resources and information indicating duplicate CSI-RS transmissions on CSI-RS resources via the same transmission beam of the base station, as well as... The resource information includes: Regarding the number of antenna ports for CSI-RS resources, Information regarding the resource mode that indicates the initial orthogonal frequency division multiplexing (OFDM) symbol number within the resource block, and Information regarding the frequency band for at least one CSI-RS.

3. The method according to claim 1, further comprising: Receive MAC CE from the base station for deactivating semi-persistent CSI-RS resources. Semi-persistent CSI-RS is received based on the periodicity between the activation and deactivation of semi-persistent CSI-RS resources.

4. The method according to claim 1, further comprising: Send information about the UE's ability to receive beams to the base station; as well as Receive information from the base station for configuring the UE report beam identifier ID and reference signal received power RSRP. The at least one CSI-RS is transmitted on different OFDM symbols.

5. A method performed by a base station (BS), the method comprising: Send first information to the user equipment (UE), the first information configuring the semi-persistent channel state information (CSI) - reference signal (RS) resources included in the radio resource control (RRC) message; Send a second message to the UE, the second message configuring the non-periodic CSI-RS resources included in the RRC message; Send to the UE either a Media Access Control (MAC) control element (CE) for activating a semi-persistent CSI-RS resource configured by the first information or downlink control information for activating a non-periodic CSI-RS resource configured by the second information; Send at least one CSI-RS to the UE; In the case of receiving a MAC CE: The at least one CSI-RS includes semi-persistent CSI-RS received periodically. The MAC CE includes an identifier indicating the first information, and Information regarding the periodicity is included in the first information, and In the case of receiving DCI: The at least one CSI-RS includes a non-periodic CSI-RS.

6. The method according to claim 5, in, The first and second information include resource information about CSI-RS resources and information indicating duplicate CSI-RS transmissions on CSI-RS resources via the same transmission beam of the base station, as well as... The resource information includes: Regarding the number of antenna ports for CSI-RS resources, Information regarding the resource mode that indicates the initial orthogonal frequency division multiplexing (OFDM) symbol number within the resource block, and Information regarding the frequency band for the at least one CSI-RS.

7. The method according to claim 5, further comprising: Send a MAC CE to the UE to deactivate the semi-persistent CSI-RS resources. Semi-persistent CSI-RS is sent periodically based on the activation and deactivation of semi-persistent CSI-RS resources.

8. The method according to claim 5, further comprising: The UE receives information about its ability to receive the number of beams. as well as Send information to the UE to configure the UE Report Beam Identifier ID and Reference Signal Received Power RSRP. The at least one CSI-RS is transmitted on different OFDM symbols.

9. A user equipment (UE), comprising: transceiver; and A controller, coupled to the transceiver and configured to perform the method according to any one of claims 1 to 4.

10. A base station, comprising: transceiver; and A controller, coupled to a transceiver, is configured to perform the method according to any one of claims 5 to 8.

Images