Method and apparatus for uplink transmit beam selection

Abstract

The present disclosure provides a method and apparatus for uplink transmit beam selection. A method for operating a user equipment (UE) includes receiving configuration information including information about a plurality of measurement reference signal (RS) resources and information about a beam report, measuring the measurement RS resources, and computing the beam report based on the measurements. The method further includes determining whether a maximum permissible exposure (MPE) limit is satisfied and transmitting the beam report. The content of the beam report depends on whether the MPE limit is satisfied.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to wireless communication systems, and more particularly to beam selection. BACKGROUND

[0002] To meet increasing demand with respect to wireless data traffic after deployment of 4th generation (4G) communication systems, efforts have been made to develop an improved 5th generation (5G) or pre-5G communication system. The 5G or pre-5G communication system is also called a 'beyond 4G network' or a 'post long term evolution (LTE) system'. The 5G communication system is considered to be implemented in higher frequency (millimeter wave) bands, e.g., 60 gigahertz (GHz) bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beam forming, and large scale antenna techniques are discussed with 5G communication systems. In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, a device-to-device (D2D) communication, wireless backhaul, a moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation and the like. In the 5G system, hybrid frequency shift keying (FSK) and Feher's quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), a non-orthogonal multiple access (NOMA), and a sparse code multiple access (SCMA) as an advanced access technology have been developed.

[0003] The Internet, which is a human centered connectivity network where humans generate and consume information, is now evolving to the Internet of Things (IoT) where distributed entities, such as things, exchange and process information without human intervention. The Internet of Everything (IoE), which is a combination of the IoT technology and the Big data processing technology through connection with a cloud server, has emerged as a new paradigm for the IoT. The IoT includes technologies, such as the sensor network, Machine Type Communication (MTC), and Machine-to-Machine (M2M) communication, and the Internet of Things (IoT), Machine Type Communication (MTC), Machine-to-Machine (M2M) communication, and the like. The Internet of Things (IoT) is a Big data processing technology capable of processing of large amounts of data collected from a sensor network, Machine Type Communication (MTC), and the like, through connection with a cloud server, and the like.

[0004] In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as a sensor network, MTC, and M2M communication can be implemented by beamforming, MIMO, and array antennas. Application of a cloud RAN as the above-described big data processing technology can also be considered as an example of convergence between the 5G technology and the IoT technology. SUMMARY

[0005] TECHNICAL PROBLEM

[0006] The disclosure provides a method and apparatus for uplink transmission beam selection. BRIEF DESCRIPTION OF DRAWINGS

[0007] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals represent like parts:

[0008] Figure 1 An example wireless network is illustrated in accordance with various embodiments of the present disclosure;

[0009] Figure 2A And Figure 2B An example wireless transmit and receive path is illustrated in accordance with various embodiments of the present disclosure;

[0010] Figure 3A An example UE is illustrated in accordance with various embodiments of the present disclosure;

[0011] Figure 3B An example BS is illustrated in accordance with various embodiments of the present disclosure;

[0012] Figure 4 An example beamforming architecture of a transmitter is illustrated in accordance with various embodiments of the present disclosure, in which one channel state information reference signal (CSI-RS) port is mapped onto a large number of analog-controlled antenna elements;

[0013] Figure 5 A flow diagram of example UL beam management with aperiodic (AP) CSI-RS triggering and beam reporting is illustrated in accordance with one or more embodiments of the present disclosure;

[0014] Figure 6 A flow diagram of example UL beam management with AP SRS triggering is illustrated in accordance with one or more embodiments of the present disclosure;

[0015] Figure 7 A flow diagram of example UE-initiated beam reporting is illustrated in accordance with one or more embodiments of the present disclosure;

[0016] Figure 8 A flow diagram of example UE-initiated beam reporting is illustrated in accordance with one or more embodiments of the present disclosure;

[0017] Figure 9 A flowchart illustrating an example UE-initiated beam selection is shown in accordance with one or more embodiments of the present disclosure;

[0018] Figure 10 A flowchart illustrating an example method in which a UE receives configuration information for a plurality of measurement RS resources and a beam report is shown in accordance with one or more embodiments of the present disclosure; and

[0019] Figure 11 A flowchart illustrating an example method in which a BS generates configuration information for a plurality of measurement RS resources and a beam report is shown in accordance with one or more embodiments of the present disclosure.

[0020] Figure 12 A base station according to embodiments of the present disclosure is shown.

[0021] Figure 13 A user equipment (UE) according to embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0022] Various embodiments of the present disclosure provide methods and apparatuses for uplink transmission beam selection.

[0023] According to embodiments of the present disclosure, a user equipment (UE) is provided, comprising: a transceiver configured to receive configuration information including information about measurement reference signal (RS) resources and information about a beam report; a processor operably connected to the transceiver, the processor configured to measure the measurement RS resources, compute the beam report based on the measurement, and determine whether a maximum permissible exposure (MPE) limit is satisfied, and the transceiver is further configured to transmit the beam report, wherein content of the beam report depends on whether the MPE limit is satisfied.

[0024] In an embodiment, at least one of the measurement RS resources is a synchronization signal block (SSB) or a channel state information RS (CSI-RS).

[0025] In an embodiment, the beam report includes at least one resource indicator and a layer-1 RS received power (L1-RSRP) associated with the at least one resource indicator.

[0026] In an embodiment, the beam report includes an indicator, and the processor is further configured to set the indicator to a first value when the MPE limit is satisfied and to a second value when the MPE limit is not satisfied.

[0027] In an embodiment, the beam report includes at least one resource indicator and a layer-1 RS received power (L1-RSRP) associated with the at least one resource indicator, such that the MPE limit is satisfied.

[0028] In an embodiment, the beam report includes at least one resource indicator and a layer-1 signal-to-interference-and-noise ratio (L1-SINR) associated with the at least one resource indicator.

[0029] In an embodiment, the beam report includes at least one resource indicator and an uplink transmit configuration indication (UL TCI) associated with the at least one resource indicator.

[0030] According to an embodiment of the disclosure, a base station (BS) is provided, including a processor configured to generate configuration information including information about a plurality of measurement reference signal (RS) resources and information of a beam report, and a transceiver operatively connected to the processor, the transceiver being configured to transmit the configuration information and receive the beam report, wherein content of the beam report depends on whether a maximum permissible exposure (MPE) limit is satisfied.

[0031] In an embodiment, at least one of the measurement RS resources is a synchronization signal block (SSB) or a channel state information RS (CSI-RS).

[0032] In an embodiment, the beam report includes at least one resource indicator and a layer-1 RS received power (L1-RSRP) associated with the at least one resource indicator.

[0033] In an embodiment, the beam report includes an indicator, and the indicator is a first value when the MPE limit is satisfied and a second value when the MPE limit is not satisfied.

[0034] In an embodiment, the beam report includes at least one resource indicator and a layer-1 RS received power (L1-RSRP) associated with the at least one resource indicator, such that the MPE limit is satisfied.

[0035] In an embodiment, the beam report includes at least one resource indicator and a layer-1 signal-to-interference-and-noise ratio (L1-SINR) associated with the at least one resource indicator.

[0036] According to embodiments of the disclosure, a method for operating a user equipment (UE) is provided, the method comprising receiving configuration information including information about a plurality of measurement reference signal (RS) resources and information about a beam report, measuring the measurement RS resources, computing the beam report based on the measuring, determining whether a maximum permissible exposure (MPE) limit is satisfied, and transmitting the beam report, wherein a content of the beam report depends on whether the MPE limit is satisfied.

[0037] In an embodiment, at least one of the measurement RS resources is a synchronization signal block (SSB) or a channel state information RS (CSI-RS).

[0038] In an embodiment, the beam report includes at least one resource indicator and a layer 1 RS received power (L1-RSRP) associated with the at least one resource indicator.

[0039] In an embodiment, the beam report includes an indicator, and the indicator is a first value when the MPE limit is satisfied and a second value when the MPE limit is not satisfied.

[0040] In an embodiment, the beam report includes at least one resource indicator and a layer 1 RS received power (L1-RSRP) associated with the at least one resource indicator, such that the MPE limit is satisfied.

[0041] In an embodiment, the beam report includes at least one resource indicator and a layer 1 signal to interference noise ratio (L1-SINR) associated with the at least one resource indicator.

[0042] In an embodiment, the beam report includes at least one resource indicator and an uplink transmission configuration indication (UL TCI) associated with the at least one resource indicator.

[0043] Other technical features can be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

[0044]

EMBODIMENT

[0045] Before undertaking the below description, it can be advantageous to set forth definitions of certain words and phrases used throughout this disclosure. The term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms “transmit,” “receive,” and “communicate,” as well as derivatives thereof, encompass both direct and indirect communication. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and / or. The phrase “associated with,” as well as derivatives thereof, means to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, have, have a relationship to or with, or the like. The term “controller” means any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller can be centralized or distributed, whether locally or remotely. The phrase “at least one of’ means one or more items, and the

[0046] Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof that perform one or more operations. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of storing computer readable program code, such as a

[0047] Definitions for other certain words and phrases used throughout this disclosure are also provided. Those of ordinary skill in the art will understand that in many, if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.

[0048] The following discussion Figures 1 to 13 The various embodiments discussed below and in the present disclosure are merely for illustration and should not be taken as limiting in any respect the scope of the present disclosure. Those skilled in the art will appreciate the principles of the present disclosure can be implemented in any suitably arranged wireless communication system.

[0049] The following documents and standards descriptions are hereby incorporated by reference into the present disclosure as if fully set forth herein: 3GPP Technical Specification (TS) 36.211 version 12.4.0, “E-UTRA, Physical channels and modulation” (“REF 1”); 3GPP TS 36.212 version 12.3.0, “E-UTRA, Multiplexing and channel coding” (“REF 2”); 3GPP TS 36.213 version 12.4.0, “E-UTRA, Physical layer procedures” (REF 3); 3GPP TS 36.321 version 12.4.0, “E-UTRA, Medium Access Control (MAC) protocol specification” (REF 4); 3GPP TS 36.331 version 12.4.0, “E-UTRA, Radio Resource Control (RRC) protocol specification” (“REF 5”); 3GPP Technical Specification (TS) 38.211 version 16.0.0, “NR, Physical channels and modulation” (“REF 6”); 3GPP TS 38.212 version 16.0.0, “NR, Multiplexing and channel coding” (“REF 7”); 3GPP TS 38.213 version 16.0.0, “NR, Physical layer procedures for control” (“REF 8”); 3GPP TS 38.214 version 16.0.0, “NR, Physical layer procedures for data” (“REF 9”); 3GPP TS 38.321 version 16.0.0, “NR, Medium Access Control (MAC) protocol specification” (“REF 10”); 3GPP TS 38.331 version 16.0.0, “NR, Radio Resource Control (RRC) protocol specification” (“REF 11”); and 3GPP TS 38.215 version 16.0.0, “NR, Physical layer measurements” (“REF 12”).

[0050] To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop and deploy an improved 5G / NR or pre-5G / NR communication system. Therefore, the 5G / NR or pre-5G / NR communication system is also called a 'Beyond 4G Network' or a '5G Network'. The 5G / NR communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 28 GHz or 60 GHz bands, so as to accomplish higher data rates. To decrease a propagation loss of radio waves and increase a transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques have been discussed in 5G / NR communication systems.

[0051] In addition, in 5G / NR communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, a technology for reception-end interference cancellation, a cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation, and the like.

[0052] The discussion of 5G systems and frequency bands associated therewith is for reference because certain embodiments of the present disclosure can be implemented in 5G systems. However, the present disclosure is not limited to 5G systems or frequency bands associated therewith, and embodiments of the present disclosure can be used in conjunction with any frequency bands. For example, aspects of the present disclosure can also apply to deployments of 5G communication systems that can use terahertz (THz) bands, 6G or even higher versions.

[0053] Wireless communication is one of the most successful innovations in modern history. As smartphones and other mobile data devices such as tablets, "notebook" computers, netbooks, e-book readers, and machine-type devices are increasingly popular among consumers and enterprises, demand for wireless data traffic is growing rapidly. To meet the high-speed growth of mobile data traffic and support new applications and deployments, improving the efficiency and coverage of wireless interfaces is critical.

[0054] A mobile device or user equipment can measure the quality of a downlink channel and report that quality to a base station, which can determine whether various parameters should be adjusted during communication with the mobile device. Existing channel quality reporting procedures in wireless communication systems are insufficient to report channel state information associated with large two-dimensional array transmit antennas, or generally channel state information associated with antenna array geometries that accommodate a large number of antenna elements.

[0055] Figure 1 An example wireless network 100 according to various embodiments of the present disclosure is shown.Figure 1 The embodiment of wireless network 100 shown is for illustration only. Other embodiments of the wireless network 100 can be used without departing from the scope of the present disclosure.

[0056] Wireless network 100 includes BS 101, BS 102, and BS 103. BS 101 communicates with BS 102 and BS 103. BS 101 also communicates with at least one Internet Protocol (IP) network 130, such as the Internet, a proprietary IP network, or other data network. The option term "eNB" (enhanced Node B) or "gNB" (general Node B) can also be used in place of "BS." Depending on the network type, other well-known terms can be used instead of "gNB" or "BS," such as "base station" or "access point." For the sake of convenience, the terms "gNB" and "BS" are used in the present disclosure to refer to the network infrastructure components that provide wireless access to remote terminals. Depending on the network type, other well-known terms can be used instead of "user equipment" or "UE," such as "mobile station," "subscriber station," "remote terminal," "wireless terminal," or "user device." For the sake of convenience, the terms "user equipment" and "UE" are used in the present disclosure to refer to remote wireless equipment that wirelessly accesses a gNB, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered a fixed device (such as a desktop computer or vending machine).

[0057] BS 102 provides wireless broadband access to the network 130 for a first plurality of UEs within a coverage area 120 of the BS 102. The first plurality of UEs includes a UE 111, which can be located in a small business; a UE 112, which can be located in an enterprise (E); a UE 113, which can be located in a WiFi hotspot (HS); a UE 114, which can be located in a first residence (R); a UE 115, which can be located in a second residence (R); and a UE 116, which can be a mobile device (M), such as a cell phone, a wireless laptop, a wireless PDA, or the like. BS 103 provides wireless broadband access to the network 130 for a second plurality of UEs within a coverage area 125 of the BS 103. The second plurality of UEs includes the UE 115 and the UE 116. In some embodiments, one or more of the BSs 101-103 can communicate with each other and with the UEs 111-116 using 5G, LTE, LTE-A, WiMAX, or other advanced wireless communication techniques.

[0058] Dotted lines show the approximate extents of the coverage areas 120 and 125 as roughly circular for purposes of illustration and explanation only. It is to be understood that coverage areas associated with gNBs, such as the coverage areas 120 and 125, can have other shapes, including irregular shapes, depending upon configuration of the gNBs and the radio environment associated with natural and man-made obstructions.

[0059] As described in more detail below, one or more of the gNBs 101, 102, and 103 transmit beam selection information to the UEs 111-116 and configure the UEs 111-116 for beam selection, as described in embodiments of the present disclosure. In various embodiments, one or more of the UEs 111-116 receive the beam selection information, as described in embodiments of the present disclosure.

[0060] Although Figure 1 various changes can be made to Figure 1 wireless network 100. For example, the wireless network 100 could include any number of gNBs and any number of UEs in any suitable arrangement. The gNB 101 could communicate with any number of UEs and provide those UEs with wireless broadband access to the network 130. Similarly, each gNB 102-103 could communicate with the network 130 and provide UEs with direct wireless broadband access to the network 130. Further, the gNBs 101, 102, and / or 103 could provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0061] Figure 2A and Figure 2B An example wireless transmit and receive path is shown and described. In the following description, the transmit path 200 can be described as implemented at a gNB (such as the gNB 102), and the receive path 250 can be described as implemented at a UE (such as the UE 116). However, it will be understood that the receive path 250 can be implemented at a gNB and that the transmit path 200 can be implemented at a UE. In some embodiments, the receive path 250 is configured to receive beam selection information as described in embodiments of the present disclosure.

[0062] The transmit path 200 includes a channel coding and modulation block 205, a serial-to-parallel (S-to-P) block 210, a Size N inverse fast Fourier transform (IFFT) block 215, a parallel-to-serial (P-to-S) block 220, a “add cyclic prefix” block 225, and a frequency up-converter (UC) 230. The receive path 250 includes a frequency down-converter (DC) 255, a “remove cyclic prefix” block 260, a serial-to-parallel (S-to-P) block 265, a Size N fast Fourier transform (FFT) block 270, a parallel-to-serial (P-to-S) block 275, and a channel decoding and demodulation block 280.

[0063] In the transmit path 200, the channel coding and modulation block 205 receives a set of information bits, applies coding (such as convolutional, turbo, or low-density parity check (LDPC) coding), and modulates the input bits (such as utilizing quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a sequence of frequency-domain modulation symbols. The S-to-P block 210 converts (such as de-multiplexes) the serial modulated symbols to parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in the gNB 102 and the UE 116. The Size N IFFT block 215 performs an IFFT operation on the N parallel symbol streams to generate time-domain output signals. The P-to-S block 220 converts (such as multiplexes) the parallel time-domain output symbols from the Size N IFFT block 215 to generate a serial time-domain signal. The “add cyclic prefix” block 225 inserts a cyclic prefix to the time-domain signal. The UC 230 modulates (such as up-converts) the output of the “add cyclic prefix” block 225 to an RF frequency for transmission via a wireless channel. The signal can also be filtered at baseband before conversion to the RF frequency.

[0064] The RF signals transmitted from the gNB 102 arrive at the UE 116 after passing through the wireless channel, and the reverse operations to those performed at the gNB 102 are performed at the UE 116. The DC 255 down-converts the received signal to baseband frequency, and the “remove cyclic prefix” block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. The serial-to-parallel block 265 converts the time-domain baseband signal to parallel time-domain signals. The Size N FFT block 270 performs the FFT algorithm to generate N parallel frequency-domain signals. The parallel-to-serial block 275 converts the parallel frequency-domain signals to a sequence of modulated data symbols. The channel decoding and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

[0065] As described in more detail below, the transmit path 200 or receive path 250 can perform signaling for beam reporting. Each of the gNBs 101-103 can implement a transmit path 200 similar to that used for transmitting in the downlink to UEs 111-116 and can implement a receive path 250 similar to that used for receiving in the uplink from UEs 111-116. Similarly, each UE 111-116 can implement a transmit path 200 for transmitting in the uplink to gNBs 101-103 and can implement a receive path 250 for receiving in the downlink from gNBs 101-103.

[0066] Figure 2A and Figure 2B Each of the components shown in FIGS. 7-9 can be implemented using only hardware or using a combination of hardware and software / firmware. As a particular example, Figure 2A and Figure 2B At least some of the components shown in FIGS. 7-9 can be implemented in software, while other components can be implemented by configurable hardware or a mixture of software and configurable hardware. For instance, the N-point FFT block 270 and the N-point IFFT block 215 can be implemented as configurable software algorithms where the value of N can be modified according to the implementation.

[0067] Further, although described as using FFTs and IFFTs, this is exemplary only and should not be interpreted as limiting the scope of the disclosure. Other types of transforms can be used, such as discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) functions. It will be appreciated that for DFT and IDFT functions, the value of the variable N can be any integer (such as 1, 2, 3, 4, etc.), while for FFT and IFFT functions, the value of the variable N can be any integer that is a power of 2 (such as 1, 2, 4, 8, 16, etc.).

[0068] Although Figure 2A and Figure 2B show examples of wireless transmit and receive paths, various changes can be made to Figure 2A and 2B For example, Figure 2A and Figure 2B Various components in Figure 2A and Figure 2B are intended to be illustrative of example types of transmit and receive paths that can be used in a wireless network. Other suitable architectures can be used to support wireless communication in a wireless network.

[0069] Figure 3A An example UE 116 according to the present disclosure is shown in FIG. 10. Figure 3A The embodiments of the UE 116 shown in FIG. 10 are for illustration only and Figure 1UEs 111-115 can have the same or similar configurations. However, UEs have a wide variety of configurations, and Figure 3A This disclosure is not intended to limit the scope to any particular implementation of the UE.

[0070] UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a transmit (TX) processing circuitry 315, a microphone 320, and a receive (RX) processing circuitry 325. UE 116 also includes a speaker 330, a processor 340, an input / output (I / O) interface 345, an input 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) program 361 and one or more applications 362.

[0071] RF transceiver 310 receives data from antenna 305. Figure 1 The gNB of the wireless network 100 transmits an input RF signal. RF transceiver 310 down-converts the input RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to RX processing circuitry 325, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. RX processing circuitry 325 transmits the processed baseband signal to speaker 330 (e.g., for voice data) or processor 340 for further processing (e.g., for web browsing data).

[0072] The TX processing circuit 315 receives analog or digital voice data from the microphone 320, or other output baseband data (such as network data, email, or interactive video game data) from the processor 340. The TX processing circuit 315 encodes, multiplexes, and / or digitizes the output baseband data to generate a processed baseband or IF signal. The RF transceiver 310 receives the processed baseband or IF signal from the TX processing circuit 315 and up-converts the baseband or IF signal into an RF signal, which is then transmitted via the antenna 305.

[0073] Processor 340 may include one or more processors or other processing devices and executes OS program 361 stored in memory 360 to control the overall operation of UE 116. For example, based on well-known principles, processor 340 may control the reception of forward channel signals and the transmission of reverse channel signals via RF transceiver 310, RX processing circuitry 325, and TX processing circuitry 315. In some embodiments, processor 340 includes at least one microprocessor or microcontroller.

[0074] The processor 340 can execute other processes and programs resident in the memory 360, such as operations for beam selection of systems described in the embodiments of the present disclosure. The processor 340 can move data into or out of the memory 360 in

[0075] The processor 340 is also coupled to the input 350 (e.g., keyboard, touchscreen, buttons, and the like) and the display 355. The operator of the UE 116 can use the input 350 to enter data into the UE 116. The display 355 can be a liquid crystal display or other display capable of rendering text and / or at least limited graphics, such as from web sites.

[0076] The memory 360 is coupled to the processor 340. The memory 360 can include at least one of random access memory (RAM), flash memory, and other read-only memory (ROM).

[0077] As described in greater detail below, the UE 116 can perform signaling and calculations for beam selection. Although Figure 3A One example of a UE 116 is shown, but various changes can be made Figure 3A to the design. For example, Figure 3A Various components in the UE 116 can be combined, further subdivided, or omitted and additional components can be added according to particular needs. As a particular example, the processor 340 can be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Although Figure 3A The UE 116 is shown as a mobile telephone or smartphone, but the UE can be configured to operate as other types of mobile or stationary devices.

[0078] Figure 3B An example gNB 102 according to this disclosure is shown. Figure 3B The embodiment of the gNB 102 shown is for illustration only Figure 1 Other gNBs having the same or a similar configuration can be included in the Figure 3B The scope of the present disclosure is not limited to the gNB 102 having any particular

[0079] like Figure 3B As shown, gNB 102 includes multiple antennas 370a-370n, multiple RF transceivers 372a-372n, transmit (TX) processing circuitry 374, and receive (RX) processing circuitry 376. In some embodiments, one or more of the multiple antennas 370a-370n include a 2D antenna array. gNB 102 also includes a controller / processor 378, a memory 380, and a backhaul or network interface 382.

[0080] RF transceivers 372a-372n receive input RF signals from antennas 370a-370n, such as signals transmitted by the UE or other gNBs. RF transceivers 372a-372n down-convert the input RF signals to generate IF or baseband signals. The IF or baseband signals are sent to RX processing circuitry 376, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signals. RX processing circuitry 376 transmits the processed baseband signal to controller / processor 378 for further processing.

[0081] The TX processing circuit 374 receives analog or digital data (such as voice data, network data, email, or interactive video game data) from the controller / processor 378. The TX processing circuit 374 encodes, multiplexes, and / or digitizes the output baseband data to generate a processed baseband or IF signal. RF transceivers 372a-372n receive the processed baseband or IF signal from the TX processing circuit 374 and up-convert the baseband or IF signal into an RF signal, which is then transmitted via antennas 370a-370n.

[0082] The controller / processor 378 may include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 378 may control the RF transceivers 372a-372n, the RX processing circuitry 376, and the TX processing circuitry 374 to receive forward channel signals and transmit reverse channel signals, based on well-known principles. The controller / processor 378 may also support additional functions, such as more advanced wireless communication capabilities. In some embodiments, the controller / processor 378 includes at least one microprocessor or microcontroller.

[0083] The controller / processor 378 can execute programs and other processes, such as an operating system, residing in the memory 380. The controller / processor 378 can support configuring the UE for uplink beam selection, as described in embodiments of this disclosure. In some embodiments, the controller / processor 378 supports communication between entities, such as network RTC. As part of the execution process, the controller / processor 378 can move data into or out of the memory 380.

[0084] The controller / processor 378 is also coupled to a backhaul or network interface 382. The backhaul or network interface 382 allows the gNB 102 to communicate with other devices or systems via a backhaul connection or network. The backhaul or network interface 382 can support communication over any suitable wired or wireless connection. For example, when the gNB 102 is implemented as part of a cellular communication system (such as a cellular communication system supporting 5G or New Radio access technologies or NR, LTE, or LTE-A), the backhaul or network interface 382 can allow the gNB 102 to communicate with other gNBs via a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the backhaul or network interface 382 can allow the gNB 102 to communicate via a wired or wireless local area network or via a wired or wireless connection to a larger network (such as the Internet). The backhaul or network interface 382 includes any suitable architecture supporting communication over a wired or wireless connection, such as an Ethernet or RF transceiver.

[0085] Memory 380 is coupled to controller / processor 378. Memory 380 may include at least one of RAM, flash memory, and other ROM. In some embodiments, multiple instructions, such as a BIS algorithm, are stored in the memory. When executed, the multiple instructions cause controller / processor 378 to perform the BIS process and decode the received signal after subtracting at least one interference signal determined by the BIS algorithm.

[0086] As described in more detail below, the transmit and receive paths of gNB 102 (implemented using RF transceivers 372a-372n, TX processing circuitry 374, and / or RX processing circuitry 376) respectively send configuration information for beam selection to the UE and receive beam selection information generated therefrom.

[0087] although Figure 3B An example of gNB 102 is shown, but it is possible to compare it with other models. Figure 3B Various changes can be made. For example, gNB102 can include... Figure 3A Each component may be shown in any number. As a particular example, an access point may include multiple backhaul or network interfaces 382, ​​and the controller / processor 378 may support routing functionality to route data between different network addresses. As another example, although shown as a single instance including TX processing circuitry 374 and a single instance including RX processing circuitry 376, gNB 102 may include multiple instances of each (such as one per RF transceiver).

[0088] Release 13 LTE supports up to 16 CSI-RS antenna ports, which enables a gNB to be equipped with a large number of antenna elements, such as 64 or 128. In this case, multiple antenna elements are mapped onto one CSI-RS port. In addition, up to 32 CSI-RS ports will be supported in Release 14 LTE and Release 15 NR. For next generation cellular systems such as 5G, the maximum number of CSI-RS ports is expected to remain roughly the same.

[0089] For millimeter wave bands, although the number of antenna elements can be larger for a given form factor, the number of CSI-RS ports (which can correspond to the number of digitally precoded ports) tends to be limited due to hardware constraints, such as the feasibility of installing a large number of ADCs / DACs at millimeter wave frequencies, as Figure 4 The transmitter 400 is shown. For example, the transmitter 400 can exist in a gNB 102 or UE 116. Figure 1 The transmitter 400 is shown. For example, the transmitter 400 can exist in a gNB 102 or UE 116. Figure 4 Embodiments of the transmitter 400 are for illustration only. Other transmitters can have the same or similar configuration.

[0090] Figure 4 An example beamforming architecture of a transmitter 400 is shown, in which one channel state information reference signal (CSI-RS) port is mapped onto a large number of analog-controlled antenna elements, in accordance with various embodiments of the present disclosure. Embodiments of the transmitter 400 are for illustration. As shown, Figure 4 One CSI-RS port is mapped onto a large number of antenna elements, which can be controlled by a set of analog phase shifters 401. One CSI-RS port can correspond to one subarray, which produces a narrow analog beam through analog beamforming 405. By changing the phase shifter set over a symbol or subframe or time slot (which includes a set of symbols and / or can include a transmission time interval), the analog beam can be configured to sweep over a wider range of angles 420. The number of subarrays (equal to the number of RF chains) is the same as the number of CSI-RS ports N CSI-PORT Digital beamforming unit 410 performs a linear combination over the N CSI-PORT analog beams to further increase precoding gain. While the analog beams are wideband (and thus not frequency-selective), the digital precoding can vary over frequency subbands or resource blocks. Receiver operations can be similarly envisioned.

[0091] Since the above system utilizes multiple analog beams for transmission and reception (where one or a small number of analog beams are selected from a large number of analog beams, e.g., after a training duration, from time to time), the term “multi-beam operation” is used to refer to the overall system aspect. For the purpose of illustration, this includes indicating an allocated DL or UL transmission (TX) beam (also referred to as “beam indication”), measuring at least one reference signal for computing and performing a beam report (also referred to as “beam measurement” and “beam report”, respectively), and receiving a DL or UL transmission by selecting a corresponding reception (RX) beam.

[0092] The above system is also applicable to higher frequency bands, e.g., > 52.6 GHz. In this case, the system can only employ analog beams. Due to the O2 absorption loss around 60 GHz frequencies (additional loss of about 10 dB at 100 meter distance), more sharper analog beams (hence larger number of radiators in the array) will be needed to compensate for the additional path loss.

[0093] In Rel-15 NR, multi-beam operation is mainly designed for a single transmission-reception point (TRP) and a single antenna panel. Therefore, the specification supports beam indication of one TX beam, where the TX beam is associated with a reference RS. For DL beam indication and measurement, the reference RS can be a non-zero-power (NZP) CSI-RS and / or SSB (synchronization signal block, which includes primary synchronization signal, secondary synchronization signal, and PBCH). Here, DL beam indication is done via a TCI field in DL-related downlink control information (DCI) that includes an index to one (e.g., only one) allocated reference RS. For UL beam indication and measurement, the reference RS can be a NZP CSI-RS, SSB, and / or SRS. Here, UL beam indication is done via an SRS resource indicator (SRI) field in UL-related DCI that links to one (e.g., only one) reference RS. This linkage is configured through higher layer signaling using a SpatialRelationlnfo RRC parameter. In essence, only one TX beam can be indicated to a UE.

[0094] In one example related to Rel. 15 / 16 NR, beam management is designed to share the same framework as CSI acquisition. However, this compromises the performance of beam management, especially for FR2. This is because beam management mainly operates using analog beams (a characteristic of FR2), which is fundamentally different from CSI acquisition (designed with FR1 in mind). As a result, Rel. 15 / 16 beam management becomes cumbersome and is unlikely to meet more aggressive use cases that require a large number of beams and fast beam switching (e.g., higher frequency bands, high mobility, and / or more narrow analog beams). Moreover, Rel. 15 / 16 is designed to accommodate many unknown or basic capabilities (e.g., a UE cannot communicate beams). For flexibility, it creates many options. This becomes burdensome for L1 control signaling, so many reconfigurations are performed via RRC signaling (higher layer configuration). While this avoids L1 control overhead, it either results in high latency (if reconfigurations are performed sparsely) or imposes high usage of PDSCH (as RRC signaling consumes PDSCH resources).

[0095] In one example related to Rel. 15 / 16 NR, when beam correspondence is utilized, UL beam selection can be performed by measuring DL RS (CSI-RS and / or SSB) and CRI reporting (e.g., SINR RSRP) with corresponding beam metrics. That is, based on CRI / RSRP or CRI / SINR reporting from a UE, a network (NW) can assume that the UE performs UL transmission on PUSCH with an UL TX beam associated with one of the latest CRI reports (especially the one with the highest RSRP or / SINR). Likewise, the UE can assume that the NW is aware of this UE selection. Therefore, a separate UL beam indication (e.g., through an SRI field or UL-TCI field in a respective UL grant) is not needed.

[0096] In Rel. 15 / 16 NR, when beam correspondence is not utilized, UL beam selection can be performed via the NW selecting an UL TX beam and indicating the UL TX beam to a UE via an UL grant (signaled via an SRI field or UL-TCI field, essentially indicating an UL TCI state associated with the UL TX beam). This selection is enabled by measuring SRS transmitted from the UE (configured by the NW).

[0097] In either case, when an event causes the UE to have to select a different UL TX beam than what the NW expects, some additional mechanism is needed to ensure that the NW is aware of the UE’s decision. For example, such an event can occur when the UE’s transmission is limited by so-called maximum permissible exposure (MPE) regulations, especially in North America. That is, to prevent any excessive electromagnetic exposure on vulnerable soft tissue (e.g., brain tissue), the UE is to avoid sending high-energy signals along certain directions (e.g., towards the head). Unfortunately, such directions can correspond to the “best” UL TX beam (e.g., associated with the CRI of the highest reported RSRP / SINR, or associated with the SRS resource that yields the best measured SINR at the NW). When the “best” UL TX beam is not used for UL transmission, some loss in UL throughput (especially coverage) will occur.

[0098] Therefore, there is a need for an efficient design to implement UL TX beam selection that not only avoids interruptions due to events such as those related to MPE regulations, but also reduces the associated loss in UL throughput.

[0099] In the following, for brevity, both FDD and TDD are considered as duplexing methods for DL and UL signaling.

[0100] Although the examples and embodiments that follow assume orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency-division multiple access (OFDMA), embodiments of the present disclosure can be extended to other OFDM-based transmission waveforms or multiple access schemes, such as filtered OFDM (F-OFDM).

[0101] The present disclosure covers several components that can be used in conjunction or combination with each other, or can operate as standalone schemes.

[0102] In the present disclosure, the term “activation” describes an operation in which the UE receives and decodes a signal from the network (or gNB) that indicates a time starting point. The starting point can be a current or future slot / subframe or symbol - the exact location indicated implicitly or explicitly, or fixed or higher-layer configured. Upon successful decoding of the signal, the UE responds accordingly. The term “deactivation” describes an operation in which the UE receives and decodes a signal from the network (or gNB) that indicates a time stopping point. The stopping point can be a current or future slot / subframe or symbol - the exact location indicated implicitly or explicitly, or fixed or higher-layer configured. Upon successful decoding of the signal, the UE responds accordingly.

[0103] Terms such as TCI, TCI state, spatial relation information, target RS, reference RS, etc. are for illustration purposes and are therefore not normative. Other terms referring to the same functionality can also be used.

[0104] The term such as UL TX beam is used for illustration purpose, thus not normative. Other terms such as UL transmit spatial filter, refer to the spatial filtering operation applied by the UE to the transmitted UL signal, can also be used to denote the same functionality.

[0105] “Reference RS” corresponds to a set of characteristics of the UL TX beam (or UL transmit spatial filter) such as direction, precoding / beamforming, number of ports, etc. For example, when the UE receives a reference RS index / ID in the UL grant, the UE applies the known characteristics of the reference RS to the granted UL transmission. The UE can receive and measure the reference RS (in this case, the reference RS is a downlink signal such as NZP CSI-RS and / or SSB), the measurement results are used to compute the beam report. When the NW / gNB receives the beam report, the NW can be better equipped with information to assign a specific UL TX beam to the UE. Alternatively, the reference RS can be transmitted by the UE (in this case, the reference RS is an uplink signal such as SRS or DMRS). When the NW / gNB receives the reference RS, the NW / gNB can measure and compute information to assign a specific UL TX beam to the UE. This option is applicable when the DL-UL beam pair correspondence holds or is assumed.

[0106] The reference RS can be dynamically triggered by the NW / gNB (e.g. via DCI in the case of AP RS), pre-configured with specific time-domain behavior (such as periodicity and offset in the case of periodic RS), or a combination of such pre-configuration and activation / deactivation (in the case of semi-persistent or SP RS).

[0107] The following embodiments are examples of DL multi-beam operation with DL beam indication by the network (NW) after the NW receives some transmission from the UE. In the first example embodiment, an aperiodic CSI-RS is transmitted by the NW and measured by the UE. While an aperiodic RS is used in these two examples, a periodic or semi-persistent RS can also be used.

[0108] For millimeter wave (or FR2) or higher frequency bands (such as > 52.6 GHz or FR4) which are particularly relevant for multi-beam operation, the transmission-reception procedure includes that the receiver selects a receive (RX) beam for a given TX beam. For UL multi-beam operation, the gNB selects an UL RX beam for each UL TX beam (corresponding to a reference RS). Thus, when UL RS (such as SRS and / or DMRS) are used as reference RS, the NW / gNB triggers or configures the UE to transmit UL RS (which is associated with the selection of UL TX beam). After receiving and measuring the UL RS, the gNB selects the UL RX beam. As a result, the TX-RX beam pair is derived. The NW / gNB can perform this operation for all configured reference RS (each reference RS or “beam sweeping”) and determine all TX-RX beam pairs associated with all reference RS configured to the UE. On the other hand, when DL RS (such as CSI-RS and / or SSB) are used as reference RS (relevant when DL-UL beam correspondence or reciprocity holds), the NW / gNB transmits the RS to the UE (which corresponds to the UL RX beam for UL and reciprocity). In response, the UE measures the reference RS (and selects the UL TX beam in the process) and reports beam metrics associated with the quality of the reference RS. In this case, the UE determines the TX-RX beam pair for each configured (DL) reference RS. Thus, although this knowledge is not available to the NW / gNB, the UE can select the UL TX beam from the knowledge about all TX-RX beam pairs upon receiving an indication from the NW / gNB that the reference RS (and thus the UL RX beam) is received.

[0109] In this disclosure, the term “resource indicator” is also abbreviated as REI for referring to an indicator of RS resource for signal / channel and / or interference measurement. This term is used for illustration purpose and thus can be replaced by any other term representing the same function. Examples of REI include the aforementioned CSI-RS resource indicator (CRI) and SSB resource indicator (SSB-RI). Any other RS can also be used for signal / channel and / or interference measurement, such as DMRS.

[0110] Figure 5 A flowchart 500 of example UL beam management with AP CSI-RS triggering and beam reporting is shown in accordance with one or more embodiments of the disclosure. Figure 5 The embodiments in the Figure 5In the example shown in FIG. 500, the UL multi-beam operation starts with the gNB / NW signaling an aperiodic CSI-RS (AP-CSI-RS) trigger or indication to the UE (step 501). The trigger or indication can be included in a DCI (UL-related or DL-related, signaled separately or jointly with aperiodic CSI request / trigger) and indicates the transmission of the AP-CSI-RS in the same (zero time offset) or later time slot / subframe (>0 time offset). Upon receiving the AP-CSI-RS transmitted by the gNB / NW (step 502), the UE measures the AP-CSI-RS and, in turn, computes and reports a “beam metric” (indicating the quality of a specific TX beam hypothesis) (step 503). Examples of such beam reports are the CSI-RS Resource Indicator (CRI) or the SSB Resource Indicator (SSB-RI), and the L1-RSRP / L1-RSRQ / L1-SINR / CQI associated with the resource indicator. Upon receiving the beam report from the UE, the NW can use the beam report to select the UL TX beam for the UE and indicate the UL TX beam selection using the SRI field in the UL-related DCI (which carries the UL grant, such as DCI format 0_1 in NR) (step 504). The SRI corresponds to the “target” SRS resource linked to the reference RS (in this case, the AP-CSI-RS) via the spatial relation information configuration. Upon successfully decoding the UL-related DCI with the SRI, the UE performs the UL transmission (such as data transmission on PUSCH) with the UL TX beam associated with the SRI (step 505).

[0111] Figure 6 A flow diagram 600 of exemplary UL beam management with AP SRS trigger is shown in accordance with one or more embodiments of the present disclosure. Figure 6 The embodiments in the preceding description are merely illustrative. In another example, as Figure 6As shown in FIG. 600, the UL multi-beam operation starts with the gNB / NW signaling an aperiodic SRS (AP-SRS) trigger or request to the UE (step 601). This trigger can be included in a DCI (either UL-related or DL-related). Upon receiving and decoding the AP-SRS trigger (step 602), the UE transmits an AP-SRS to the gNB / NW (step 603) so that the NW (or gNB) can measure the UL propagation channel and select an UL TX beam for the UE. The gNB / NW can then indicate the UL TX beam selection using the SRI field in an UL-related DCI (which carries an UL grant, such as DCI format 0_1 in NR) (step 604). The SRI corresponds to a “target” SRS resource that is linked to a reference RS (in this case, the AP-SRS) via spatial relation information configuration. Upon successfully decoding the UL-related DCI with the SRI, the UE performs UL transmission (such as data transmission on PUSCH) with the UL TX beam associated with the SRI (step 605).

[0112] In the above two example embodiments, only one UL TX beam is indicated to the UE. Extensions for multi-panel UEs can be found, for example, in U.S. Patent No. 10,887,884, which is incorporated herein by reference.

[0113] The SRI used in embodiments 500 and 600 can also be replaced with UL-TCI, where a UL-TCI field can be introduced into the relevant UL-related DCI, in place of or in addition to the SRI field in Rel-15 / 16.

[0114] Figure 5 The aperiodic CSI-RS (along with the associated aperiodic reporting) shown in Figure 6 The aperiodic SRS shown in

[0115] The present disclosure includes the following components. A first component includes example embodiments of methods that implement more efficient UE procedures for UL beam selection. A second component includes example embodiments of methods for configuring and / or utilizing the embodiments in the first component.

[0116] For the first component (i.e., the UE procedures for UL beam selection), the following example embodiments include at least one method for UL beam selection in response to an event that can cause or even necessitate the UE to change the UL TX beam selection. As mentioned above, such an event can occur, for example, when the UE transmission is limited by so-called maximum permissible exposure (MPE) regulations.

[0117] In any of the following embodiments or sub-embodiments, flowcharts are used for illustration purposes. The present disclosure covers any possible variations of the flowcharts as long as at least some components are included. Such components include evaluation of UL conditions and event-dependent UE reporting behavior.

[0118] In one embodiment (I), a UE (referred to as UE-k) is configured to report at least one CRI or SSB-RI, and optionally, along with the associated beam metrics (e.g., L1-RSRP, L1-SINR, or any other beam metrics). The time-domain behavior of such reporting can be configured as aperiodic (AP), semi-persistent (SP), or periodic (P). The UE-k is further configured with at least one DL measurement RS, such as CSI-RS or SSB.

[0119] Figure 7 A flowchart of a method 700 of example UE-initiated beam reporting is shown in accordance with one or more embodiments of the present disclosure. Embodiments of the method 700 are for illustration only and the method 700 can be implemented by a UE, such as the UEs 111-116, Figure 1 In one sub-embodiment (I.1), as shown in the method 700, Figure 7 The UE-k (configured by the NW / gNB) is configured to report N REI / beam metric pairs (N > 1, step 701). As mentioned above, in NR, any REI can be a CRI or SSB-RI. The beam metrics can represent the link quality associated with data (PDSCH) and / or dedicated control (PDCCH). Examples of beam metrics include L1-RSRP, L1-SINR, CQI, or assumed BLER, possibly accompanied by at least one measurement RS resource index / indicator. The REI indicates the DL measurement RS resource index with the corresponding beam metric. The UE-k is configured with at least N DL measurement RS resources (such as CSI-RS or SSB) by the NW / gNB. This configuration can be performed via higher layer (RRC) signaling. Optionally, the NW / gNB can dynamically signal / update a (sub)set of DL measurement RS resources via L1 or L2 DL control (PDCCH or MAC CE). The UE-k uses these resources to perform measurements and compute beam metrics.

[0120] Subsequently, the UE-k can measure the DL measurement RS (step 702), and optionally, evaluate the UL conditions (step 703) to determine whether the event of interest occurs (step 704). For example, if the event is related to MPE regulations, the UE-k can compare the REI / metric with the power spectral density (PSD) to the directional profile that reflects compliance with the MPE regulations. The UE-k can maintain the knowledge about the directions associated with the configured DL measurement RS resources, e.g., acquired during the most recent DL beam training procedure.

[0121] If the event is declared negative, the UE-k continues to report the most recently computed N REI / metric pairs (when time comes, depending on the time domain behavior), as the UE-k normally does (step 705). If the event is declared positive (e.g., at least one of the computed N REI / metric pairs does not satisfy the MPE regulation), the UE-k continues to report N REI / metric pairs (when time comes, depending on the time domain behavior), where at least one REI / metric pair is determined based on the event (step 706). For example, if the event is related to the MPE regulation, M < N REI / metric pairs are selected / determined such that the DL measurement RS resources associated with the M REIs comply with the MPE regulation. The value of M can be fixed, pre-defined, or configured via higher layer (e.g., RRC) signaling. Alternatively, the value of M can be dynamically signaled / updated via MAC CE (L2) or PDCCH (L1). Which M pairs among the N pairs can be determined by a fixed or pre-defined rule (e.g., if M = 1, M can be specified as the first pair among the N pairs), or configured via higher layer (e.g., RRC) signaling, or dynamically signaled / updated via MAC CE (L2) or PDCCH (L1).

[0122] Note that in this sub-embodiment, the NW / gNB does not necessarily know that the event has occurred. In one example, when N > 1, the NW / gNB can know that the event has occurred by comparing the beam metric values. For example, when the N REI / metric pairs are ordered in a decreasing value of the beam metric, and the first M of the N REI / metric pairs can be reported based on the event, the beam metric value of at least one of the first M REI / metric pairs can be smaller than at least one of the remaining (N-M) REI / metric pairs, thus the NW / gNB can know that the event has occurred.

[0123] Figure 8 A flowchart of an example UE-initiated beam reporting is shown in accordance with one or more embodiments of the present disclosure. Embodiments of the method 800 are for illustration only and the method 800 can be implemented by a UE, such as the UEs 111-116, Figure 1 Figure 8 ​The method 800 is shown as follows. UE-k (configured by NW / gNB) is configured to report N REI / beam metric pairs (N > 1, step 801). As mentioned above, in NR, any REI can be CRI or SSB-RI. The beam metric can represent the link quality associated with data (PDSCH) and / or dedicated control (PDCCH). Examples of beam metrics include L1-RSRP, L1-SINR, CQI, or assumed BLER, possibly accompanied by at least one measured RS resource index / indicator. REI indicates the DL measured RS resource index with the corresponding beam metric. UE-k (configured by NW / gNB) is configured with at least N DL measured RS resources (e.g., CSI-RS or SSB). This configuration can be performed via higher layer (RRC) signaling. Optionally, NW / gNB can dynamically signal / update the (sub)set of DL measured RS resources via L1 or L2 DL control (PDCCH or MAC CE). UE-k uses these resources to perform measurements and compute beam metrics.

[0124] Subsequently, UE-k can measure the DL measured RS (step 802) and evaluate the UL condition (step 803) to determine whether the event of interest occurs (step 804). For example, if the event is related to MPE regulation, UE-k can compare the REI / metric with the power spectral density (PSD) to the directional profile that reflects compliance with MPE regulation. UE-k can maintain the knowledge about the direction associated with the configured DL measured RS resources, e.g., acquired during the most recent DL beam training procedure.

[0125] If the event is declared negative, UE-k continues to report the N REI / metric pairs of the most recent computation (when time comes, depending on the time-domain behavior), as UE-k normally does (step 805).

[0126] If the event is declared positive (e.g., at least one of the N REI / metric pairs computed does not satisfy the MPE regulation), UE-k continues to report a pre-notification message to indicate to NW / gNB that the event occurs (step 806). An example of this pre-notification message can be a message of “MPE event occurred”. This message can be sent on one of the reserved UL resources (on PUCCH, PUSCH, PRACH, or any combination) or on the same resource used for the configured beam reporting. This message can be signaled as part of the CSI parameters and beam reporting that always exist (their existence is configured via RRC signaling), where the message can be reported / signaled by UE jointly with another existing CSI or beam reporting parameter or as a new parameter alone. Optionally, the message can only appear and be reported when the event occurs.

[0127] Optionally, the pre-notification message can be accompanied by a report of P > 1 REI / measure pairs. The value of P can be fixed or predetermined (e.g., P can be set to 1, or can be set to N), or configured via higher layer (e.g., RRC) signaling. Optionally, the value of P can be dynamically signaled via a MAC CE (L2) or PDCCH (L1). Optionally, the value of P can be reported by the UE jointly with the pre-notification message (or existing CSI or beam reporting parameters), or separately as a new parameter. The P REI / measure pairs are selected / determined such that the DL measurement RS resources associated with the P REIs comply with the MPE regulation. The P REI / measure pairs can be transmitted in the same UL slot as the pre-notification message (thus multiplexed together as part of the UCI), or in X slots after the pre-notification message (where X > 0). In one example, the value X can be fixed or configured from a set of fixed X values, where the configuration can be via RRC or / and MAC CE or / and DCI. In one example, the value X can depend on the channel used to report the pre-notification message or / and the P REI / measure pairs. If the P REI / measure pairs are reported in the same slot as the pre-notification message, a one-part or two-part UCI can be used. For example, if a two-part UCI is used, part 1 includes the pre-notification message. If the pre-notification message indicates that an event has occurred, the P REI / measure pairs are reported in part 2. Otherwise, N REI / measure pairs are typically included in part 2 (step 805).

[0128] In one example, the parameter P is used to jointly indicate the pre-notification message and the number of REI / measure pairs corresponding to the event being positive. For example, a value P = 0 corresponds to (indicates) the absence of a pre-notification message (i.e., no pre-notification message is signaled), while a value P > 1 corresponds to (indicates) the presence of a pre-notification message (i.e., a pre-notification message is signaled) and the number of REI / measure pairs in response to the event being declared positive.

[0129] Optionally, the pre-notification message can be accompanied by a report of P > 1 REIs (without beam metrics). Again, the value of P can be fixed or pre-configured (e.g., P can be set to 1, or can be set to N), or configured via higher layer (e.g., RRC) signaling. Optionally, the value of P can be dynamically signaled via a MAC CE (L2) or PDCCH (L1). Optionally, the value of P can be reported by the UE jointly with the pre-notification message (or existing CSI or beam reporting parameters), or separately as a new parameter. The P REIs are selected / determined such that the DL measurement RS resources associated with the P REIs comply with the MPE regulation. The P REIs can be transmitted in the same UL slot as the pre-notification message (hence multiplexed together as part of the UCI), or in X slots after the pre-notification message (where X > 0). In one example, the value X can be fixed or configured from a set of fixed X values, where the configuration can be via RRC or / and MAC CE or / and DCI. In one example, the value X can depend on the channel used to report the pre-notification message or / and the P REIs. If the P REIs are reported in the same slot as the pre-notification message, one-part or two-part UCI can be used. For example, if two-part UCI is used, part 1 includes the pre-notification message. If the pre-notification message indicates that an event has occurred, the P REIs are reported in part 2. Otherwise, N REI / metric pairs are typically included in part 2 (step 805).

[0130] In one example, the parameter P is used to jointly indicate the pre-notification message and the number of REIs corresponding to the event being positive. For example, the value P = 0 corresponds to (indicates) the absence of a pre-notification message (i.e., no pre-notification message is signaled), while the value P > 1 corresponds to (indicates) the presence of a pre-notification message (i.e., a pre-notification message is signaled) and the number of REIs in response to the event being declared positive.

[0131] Note that in this sub-embodiment, the NW / gNB knows that an event has occurred.

[0132] For all the above sub-embodiments of Embodiment I, if the UL-TCI state definition is used to link (via QCL relationship) the UL TCI state with the REI of interest (i.e., the CRI or SSB-RI utilized as described above), the REI in the above description can also refer to the UL-TCI indicating the UL TCI state associated with the DL measurement RS resource.

[0133] In another embodiment (II), a UE (referred to as UE-k) is configured with L > 1 SRS resources. The NW / gNB can use these K SRS resources to measure the UL channel conditions along L different spatial directions (represented by the precoding operation performed at the UE-k which is transparent to the NW / gNB).

[0134] Figure 9 A flowchart of an example UE-initiated beam selection is shown in accordance with one or more embodiments of the present disclosure. Embodiments of the method 900 are for illustration only and the method 900 can be implemented by a UE such as the UEs 111-116 Figure 1 Figure 9 The method 900, as shown in accordance with one or more embodiments of the present disclosure, the UE-k is configured (by the NW / gNB) to report M UL-TCIs (M > 1, step 901). Here, the UL-TCI represents the UL TCI states (via higher layer signaling) as configured in the UL TCI state definition, where the TCI states are linked / associated to the measurement RSs that can be used to represent the UL "directions" (i.e., UL TX beams). In this sub-embodiment, the UL TCI states are linked to the SRS resource indices (SRIs) that represent the configured SRS resources, since SRS is used to measure the link quality of the UL channel. The UE-k is also configured (by the NW / gNB) with L > 1 SRS resources. This configuration can be performed via higher layer (RRC) signaling. Optionally, the NW / gNB can dynamically signal / update the (sub)set of SRS resources via L1 or L2 DL control (PDCCH or MAC CE). The UE-k uses these resources to enable the NW / gNB to perform UL channel measurements.

[0135] Subsequently, the UE-k can transmit SRS (step 902) and evaluate the UL conditions (step 903) to determine if the event of interest occurs (step 904). For example, if the event is related to the MPE regulations, the UE-k can compare the precoder with the power spectral density (PSD) applied to the L SRS resources with the direction profile that reflects compliance with the MPE regulations. The UE-k maintains knowledge about the directions associated with the configured SRS resources used in the most recent SRS transmission.

[0136] If the event is declared negative, the UE-k continues with the SRS-based UL operation as the UE-k normally does, which entails not reporting any UL-TCI (step 905). This can include, for example, receiving an UL grant from the NW / gNB, where the associated UL-related DCI includes at least one UL-TCI or SRI DCI field.

[0137] ​If the event is declared positive (e.g., at least one configured LSRS resource does not satisfy the MPE regulation), UE-k continues to report a pre-notification message to indicate to the NW / gNB that the event has occurred. (Step 906). An example of this pre-notification message can be a “MPE event has occurred” message. This message can be sent on one of the reserved UL resources (on PUCCH, PUSCH, PRACH, or any combination) or on the same resources used for configured CSI and / or beam reporting. This message can be signaled as part of the always present CSI parameters and beam reporting, whose presence is configured via RRC signaling, where the message can be reported / signaled by the UE jointly with another existing CSI or beam reporting parameter or as a new parameter separately. Optionally, the message can only occur and be reported when the event has occurred.

[0138] Optionally, the pre-notification message can be accompanied by a report of P > 1 UL-TCIs. The value of P can be fixed or predetermined (e.g., P can be set to 1) or configured via higher layer (e.g., RRC) signaling. Optionally, the value of P can be dynamically signaled via a MAC CE (L2) or PDCCH (L1). Optionally, the value of P can be reported by the UE jointly with the pre-notification message (or an existing CSI or beam reporting parameter) or as a new parameter separately. The P UL-TCIs are selected / determined such that the SRS resources associated with the P UL-TCIs satisfy the MPE regulation. The P UL-TCIs can be sent in the same UL slot as the pre-notification message (thus multiplexed together as part of the UCI) or X slots after the pre-notification message (where X > 0). In one example, the value X can be fixed or configured from a set of fixed X values, where the configuration can be via RRC or / and MAC CE or / and DCI. In one example, the value X can depend on the channel used to report the pre-notification message or / and UL-TCIs. If the P UL-TCIs are reported in the same slot as the pre-notification message, one or two part UCI can be used. For example, if two part UCI is used, part 1 includes the pre-notification message. If the pre-notification message indicates that the event has occurred, the P UL-TCIs are reported in part 2 (in addition to the regular content of part 2 UCI). Otherwise, no additional content is added to part 2 UCI (Step 905).

[0139] In one example, the parameter P is used to jointly indicate the number of pre-notification messages and UL-TCIs corresponding to the event being positive. For example, the value P = 0 corresponds to (indicates) the absence of a pre-notification message (i.e., no pre-notification message is signaled), while the value P > 1 corresponds to (indicates) the presence of a pre-notification message (i.e., a pre-notification message is signaled) and the number of UL-TCIs in response to the event being declared positive.

[0140] Note that in this sub-embodiment, the NW / gNB is aware that an event has occurred.

[0141] For all the above sub-embodiments of Embodiment II, UL-TCI can also be replaced by SRI, e.g., if UL TCI is not defined / specified and / or replaced by Rel-15 / 16 spatial relation information.

[0142] For all the above sub-embodiments of Embodiment II, UL-TCI or SRI reporting can also be accompanied by some indications in the reported / recommended UL-TCI states that indicate how far they are from not satisfying the MPE regulation or how far they are from violating the MPE.

[0143] It should be noted that for this particular embodiment, the occurrence of events (such as “MPE events”) can be reduced by more frequent or UE-initiated SRS triggering, where UE-k can reconfigure the precoding applied to the L SRS resources whenever needed, so that the occurrence of events can be minimized, if not avoided.

[0144] For the second component (i.e., configuration for UL beam selection), this component can be used together with the embodiments and sub-embodiments of the first component. This is particularly relevant when more than one embodiment / sub-embodiment of the first component is utilized.

[0145] In one embodiment (III.1), the scheme can be configured via higher layer (e.g., RRC) signaling, either implicitly or explicitly using RRC parameters. For example, an example RRC parameter scheme can be used to select between at least sub-embodiment I.2 and sub-embodiment II.1. Optionally, two example RRC parameters MPE-CRI and MPE-UL TCI can be used to turn on / off sub-embodiment I.2 and sub-embodiment II.1, respectively. In one example, the configuration is subject to UE capability reported by the UE. For example, the UE reports one or both of sub-embodiment I.2 and sub-embodiment II.1 in the UE’s capability. Alternatively, one of sub-embodiment I.2 and sub-embodiment II.1 is the default scheme (supported by all UEs) and whether the UE can support the other scheme is reported by the UE in the UE’s capability signaling.

[0146] Optionally, if sub-embodiment I.2 and sub-embodiment II.1 are supported, the selected scheme can be determined by another system configuration, such as whether beam correspondence is used or the level of beam correspondence supported by the UE. For example, if beam correspondence is used and / or the UE supports the highest level of beam correspondence, sub-embodiment I.2 is configured. Otherwise, if beam correspondence is not used and / or the UE supports the lowest level of beam correspondence, sub-embodiment II.1 is configured. Such implicit configuration can also be combined with whether the MPE mitigation scheme is used. That is, the two options are relevant when the RRC parameter that regulates the use of the MPE mitigation scheme is turned on.

[0147] Any of the above variant embodiments can be used independently or in combination with at least one other variant embodiment.

[0148] Figure 10 A flowchart of an example method 1000 is shown in accordance with embodiments of the present disclosure, in which a UE receives configuration information for a plurality of measurement RS resources and a beam report. For example, the method 1000 can be performed by the UE 116. Figure 10 The embodiments of the method 1000 shown are for illustration. Variations and modifications are possible in the step sequences shown.

[0149] The method 1000 starts with a UE (referred to as UE-k) receiving from a base station configuration information for a plurality (M>1) of measurement reference signal (RS) resources, and configuration information for a beam report (step 1001). The UE measures the M measurement RS resources (step 1002), and computes a beam report based on such measurements (step 1003). For the measurement RS resources, at least one of the measurement RS resources is a synchronization signal block (SSB) or a channel state information RS (CSI-RS). The beam report can include at least one resource indicator and an associated layer 1 RS received power (L1-RSRP) for that resource indicator. For an SSB, the resource indicator would be an SSB-RI, while for a CSI-RS, the resource indicator would be a CRI. Optionally, the beam report includes at least one resource indicator and an associated layer 1 signal to interference noise ratio (L1-SINR) for that resource indicator. Optionally, the beam report includes at least one resource indicator and an associated uplink transmission configuration indication (UL TCI) for that resource indicator.

[0150] The UE determines whether the maximum permissible exposure (MPE) limit is satisfied or not (step 1004), whether before, after or in parallel with the computation of the beam report. In addition to the aforementioned resource indicators and the associated beam metrics (e.g. L1-RSRP or L1-SINR) of the resource indicators, the beam report can include an indicator that takes a first value when the MPE limit is satisfied and a second value when the MPE limit is not satisfied. The indicator can be a one-bit flag that takes a value of 1 or 0. The UE then transmits the beam report (step 1005), where the content of the beam report depends on whether the MPE limit is satisfied or not. For example, if L1-SINR is used as the beam metric, the beam report can include at least one resource indicator and the associated L1-RSRP of the resource indicator, such that the MPE limit is satisfied.

[0151] Figure 11 A flowchart illustrating an example method 1100 is shown, in which a BS generates configuration information to a UE (labeled as UE-k) regarding multiple measurement RS resources and a beam report, according to embodiments of the disclosure. For example, the method 1100 can be performed by the BS 102. Figure 11 The embodiment of the method 1100 illustrated is for purposes of example only.

[0152] The method 1100 starts with the BS generating configuration information to the UE-k regarding multiple measurement RS resources and a beam report (step 1101). The BS transmits the configuration information to the UE-k (step 1102). The BS also receives a beam report from the UE-k, which includes interference measurements based on two CSI-IM resources (step 903).

[0153] For the measurement RS resources, at least one of the measurement RS resources is a synchronization signal block (SSB) or a channel state information RS (CSI-RS). The beam report can include at least one resource indicator and the associated layer 1 RS received power (L1-RSRP) of the resource indicator. For SSB, the resource indicator would be SSB-RI, while for CSI-RS, the resource indicator would be CRI. Optionally, the beam report includes at least one resource indicator and the associated layer 1 signal to interference noise ratio (L1-SINR) of the resource indicator. Optionally, the beam report includes at least one resource indicator and the associated uplink transmission configuration indication (UL TCI) of the resource indicator.

[0154] Further, the content of the beam report depends on whether a maximum permissible exposure (MPE) limit is satisfied or not. For example, if L1-SINR is used as a beam metric, the beam report can include at least one resource indicator and an associated L1-RSRP of the resource indicator, such that the MPE limit is satisfied. In addition to the aforementioned resource indicator and the associated beam metric (such as L1-RSRP or L1-SINR) of the resource indicator, the beam report can include an indicator that takes a first value when the MPE limit is satisfied and a second value when the MPE limit is not satisfied. The indicator can be a one-bit flag that takes a value of 1 or 0.

[0155] Figure 12 A base station according to an embodiment of the disclosure is illustrated.

[0156] Reference Figure 12 The base station 1200 can include a processor 1210, a transceiver 1220, and a memory 1230. However, all of the illustrated components are not essential. The base station 1200 can be implemented by more or less components than those illustrated. Figure 12 Further, according to another embodiment, the processor 1210 and the transceiver 1220 and the memory 1230 can be implemented as a single chip.

[0157] The base station 1200 can correspond to the gNB described above. For example, the base station 1200 can correspond to the gNB 102 illustrated in FIG. 2.

[0158] The aforementioned components will now be described in detail.

[0159] The processor 1210 can include one or more processors or other processing devices that control the proposed functions, processes, and / or methods. Operations of the base station 1200 can be implemented by the processor 1210.

[0160] The transceiver 1220 can include an RF transmitter for up-converting and amplifying a transmitted signal, and an RF receiver for down-converting a frequency of a received signal. However, according to another embodiment, the transceiver 1220 can be implemented by more or less components than those illustrated in the components.

[0161] The transceiver 1220 can be connected to the processor 1210, and transmit and / or receive a signal. The signal can include control information and data. Further, the transceiver 1220 can receive a signal through a wireless channel and output the signal to the processor 1210. The transceiver 1220 can transmit a signal output from the processor 1210 through a wireless channel.

[0162] The memory 1230 can store control information or data included in a signal obtained by the base station 1200. The memory 1230 can be connected to the processor 1210 and store at least one instruction or a protocol or a parameter for the proposed functions, procedures, and / or methods. The memory 1230 can include read-only memory (ROM) and / or random access memory (RAM) and / or a hard disk and / or a CD-ROM and / or a DVD and / or other storage devices.

[0163] Figure 13 A user equipment (UE) according to an embodiment of the disclosure is illustrated.

[0164] Reference Figure 13 The UE 1300 can include a processor 1310, a transceiver 1320, and a memory 1330. However, all of the illustrated components are not essential. The UE 1300 can be implemented by more or less components than those illustrated. Figure 13 In addition, according to another embodiment, the processor 1310 and the transceiver 1320 and the memory 1330 can be implemented as a single chip.

[0165] The foregoing components will now be described in detail.

[0166] The processor 1310 can include one or more processors or other processing devices that control the proposed functions, procedures, and / or methods. The operations of the UE 1300 can be implemented by the processor 1310.

[0167] The transceiver 1320 can include an RF transmitter for up-converting and amplifying a transmitted signal, and an RF receiver for down-converting a frequency of a received signal. However, according to another embodiment, the transceiver 1320 can be implemented by more or less components than those illustrated in the components.

[0168] The transceiver 1320 can be connected to the processor 1310 and transmit and / or receive a signal. The signal can include control information and data. In addition, the transceiver 1320 can receive a signal through a wireless channel and output the signal to the processor 1310. The transceiver 1320 can transmit a signal output from the processor 1310 through a wireless channel.

[0169] The memory 1330 can store control information or data included in a signal obtained by the UE 1300. The memory 1330 can be connected to the processor 1310 and store at least one instruction or a protocol or a parameter for the proposed functions, procedures, and / or methods. The memory 1330 can include read-only memory (ROM) and / or random access memory (RAM) and / or a hard disk and / or a CD-ROM and / or a DVD and / or other storage devices.

[0170] AlthoughFigure 10 and Figure 13 respectively illustrate examples of methods for receiving configuration information and configuring a UE, but various changes can be made to Figure 10 and Figure 13 For example, while shown as a series of steps, various of the steps in each figure could overlap, occur in parallel, occur in a different order, occur multiple times, or not occur at all, in one or more embodiments.

[0171] While this disclosure has been described with examples, it should be apparent that many modifications can be made to the disclosures herein. Where desired, the disclosure can be summarized in other specific terms. Nothing herein is intended to be construed as implying any particular element, step, or function is essential to the practice of the claims. The scope of the patent topic is defined by the claims.

Claims

1. A user equipment, UE, comprising: a transceiver; and a processor, operably connected to the transceiver, the processor configured to: receive, from a base station, BS, configuration information including information about one or more measurement reference signal, RS, resources and information about a beam report, measure the one or more measurement RS resources, compute a beam report based on the measurement, determine whether a maximum permissible exposure, MPE, limit is satisfied, in response to determining that the MPE limit is not satisfied, send the beam report to the BS, wherein the beam report includes information indicating how far away from the MPE limit being satisfied, and in response to determining that the MPE limit is satisfied, determine not to send the beam report to the BS.

2. The UE of claim 1, wherein, At least one of the one or more measurement RS resources is a synchronization signal block, SSB, or a channel state information RS, CSI-RS.

3. The UE of claim 1, wherein, The beam report includes at least one resource indicator and a layer 1 RS received power, L1-RSRP, associated with the at least one resource indicator.

4. The UE of claim 1, wherein, The information in the beam report further indicates how far away from the MPE limit being satisfied associated with a beam reported in the beam report based on the measurement.

5. The UE of claim 1, wherein, The beam report includes at least one resource indicator and a layer 1 signal to interference and noise ratio, L1-SINR, associated with the at least one resource indicator.

6. The UE of claim 1, wherein, The beam report includes at least one resource indicator and an uplink transmission configuration indication, UL TCI, associated with the at least one resource indicator.

7. A base station, BS, comprising: a transceiver; and a processor, operably connected to the transceiver, the processor configured to: send, to a user equipment, UE, configuration information including information about one or more measurement reference signal, RS, resources and information about a beam report; and determine whether a maximum permissible exposure, MPE, limit is satisfied based on whether a beam report is received, wherein the beam report is received when the MPE limit is not satisfied and is not received when the MPE limit is satisfied, and wherein, when received, the beam report includes information indicating how far away from the MPE limit being satisfied.

8. The BS of claim 7, wherein, At least one of the one or more measurement RS resources is a synchronization signal block, SSB, or a channel state information RS, CSI-RS.

9. The BS of claim 7, wherein, The beam report includes at least one resource indicator and a layer 1 RS received power, L1-RSRP, associated with the at least one resource indicator.

10. The BS of claim 7, wherein, The information in the beam report further indicates how far away from the MPE limit being satisfied associated with a beam reported in the beam report.

11. The BS of claim 7, wherein, The beam report includes at least one resource indicator and a layer 1 signal to interference and noise ratio, L1-SINR, associated with the at least one resource indicator.

12. A method for operating a user equipment, UE, the method comprising: receiving, from a base station, BS, configuration information including information about one or more measurement reference signal, RS, resources and information about a beam report; measuring the one or more measurement RS resources; computing a beam report based on the measurement; determining whether a maximum permissible exposure, MPE, limit is satisfied; determining whether to send a beam report to the BS based on whether the MPE limit is satisfied; in response to determining that the MPE limit is not satisfied, sending the beam report to the BS, wherein the beam report includes information indicating how far away from the MPE limit being satisfied; in response to determining that the MPE limit is satisfied, determining not to send the beam report to the BS.

13. The method of claim 12, wherein, At least one of the one or more measurement RS resources is a synchronization signal block, SSB, or a channel state information RS, CSI-RS.

14. The method of claim 12, wherein, The beam report includes at least one resource indicator and a layer 1 RS received power, L1-RSRP, associated with the at least one resource indicator.

15. The method of claim 12, wherein, The information in the beam report is further based on the measurement to indicate how far away from satisfying the MPE limit is associated with a beam reported in the beam report.

16. The method of claim 12, wherein, The beam report includes at least one resource indicator and a layer 1 signal to interference noise ratio, L1-SINR, associated with the at least one resource indicator.

17. The method of claim 12, wherein, The beam report includes at least one resource indicator and an uplink transmission configuration indication, UL TCI, associated with the at least one resource indicator.

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