Beam management for multi-TRP via beam-group reporting

Abstract

Various aspects of the present disclosure relate to a user equipment (UE) for wireless communication with at least one memory and at least one processor coupled with the at least one memory and configured to cause the UE to receive a configuration message for a beam management procedure, receive, from a set of transmission-reception points (TRPs), a first set of reference signals via a set of wide beams and during the beam management procedure, wherein the first set of reference signals is associated with a first set of reference signal resources, and wherein each beam of the set of wide beams is associated with a corresponding beam identifier, select at least one candidate narrow beam based at least in part on the first set of reference signals received via the set of wide beams, and transmit a report that indicates the at least one candidate narrow beam to a network entity.

Description

Lenovo Docket No. SMM920240015-WO-PCT 1 BEAM MANAGEMENT FOR MULTI-TRP VIA BEAM-GROUP REPORTING CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 633,462 filed on April 12, 2024, which is hereby incorporated by reference in its entirety. TECHNICAL FIELD

[0002] The present disclosure relates to wireless communications, and more specifically to beam management in a multi-TRP environment. BACKGROUND

[0003] A wireless communications system may include one or multiple network communication devices, such as base stations, which may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE), or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers, or the like). Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G)). SUMMARY

[0004] An article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a,” “at least one,” “one or more,” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of”) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 2 AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.

[0005] A UE, processor and method for wireless communication is described. The UE may be configured to, capable of, or operable to perform one or more operations as described herein. For example, the UE may be configured to, capable of, or operable to receive a configuration message for a beam management procedure, receive, from a set of transmission-reception points (TRPs), a first set of reference signals via a set of wide beams and during the beam management procedure, wherein the first set of reference signals is associated with a first set of reference signal resources, and wherein each beam of the set of wide beams is associated with a corresponding beam identifier, select at least one candidate narrow beam based at least in part on the first set of reference signals received via the set of wide beams, and transmit a report that indicates the at least one candidate narrow beam to a network entity.

[0006] In some implementations of the UE, the processor, and the method described herein, the first indication separately indicates the at least one candidate narrow beam of each TRP of the set of TRPs

[0007] In some implementations of the UE, the processor, and the method described herein, the report indicates at least one of a received power and a signal-to-interference- and-noise-ratio (SINR) associated with each candidate narrow beam.

[0008] In some implementations of the UE, the processor, and the method described herein, the report indicates a plurality of beam groups, each beam group comprising candidate narrow beams associated with respective TRPs of the set of TRPs. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 3

[0009] In some implementations of the UE, the processor, and the method described herein, the configuration message indicates a first UE codebook for wide beam transmissions and a second UE codebook for narrow beam transmissions.

[0010] In some implementations of the UE, the processor, and the method described herein, the UE is operable to receive a second set of reference signals from a set of narrow beam groups comprising narrow beams from the set of TRPs, measure power values of the set of narrow beams groups, and transmit a second indication to the network entity indicating at least a narrow beam group of the set of narrow beam groups with a highest power value.

[0011] In some implementations of the UE, the processor, and the method described herein, the second indication indicates a plurality of narrow beam groups.

[0012] In some implementations of the UE, the processor, and the method described herein, the second indication is provided in a channel state information (CSI) report comprising at least one of a resource indicator associated with at least one of the narrow beam groups, received power of the second reference signals and received SINR of the second reference signals.

[0013] In some implementations of the UE, the processor, and the method described herein, the second reference signal resources are associated with one or more of a set of non-zero power CSI resources, a set of resources configured with a joint transmission parameter, and a set of demodulation reference signals (DMRSs).

[0014] In some implementations of the UE, the processor, and the method described herein, the first set of reference signal resources are associated with one or more of a synchronization signal (SS) block, a tracking reference signal (TRS), and a first set of non- zero power CSI resources.

[0015] In some implementations of the UE, the processor, and the method described herein, the is operable to UE to receive a third set of reference signals from a single narrow beam group including one or more narrow beam each associated with a TRP of a second set of TRPs, and select a receive beam for communicating with the second set of TRPs from a plurality of receive beams. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 4

[0016] In some implementations of the UE, the processor, and the method described herein, the plurality of receive beams include at least one narrow receive beam and at least one wide receive beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 illustrates an example of a wireless communications system in accordance with aspects of the present disclosure.

[0018] Figure 2 illustrates an example of a wireless communication system that supports beam management in accordance with aspects of the present disclosure.

[0019] Figure 3 illustrates an example of a UE receiving narrow beam groups from TRPs in accordance with aspects of the present disclosure.

[0020] Figure 4 illustrates an example of selecting a receive beam for communicating with TRPs in accordance with aspects of the present disclosure.

[0021] Figure 5 illustrates an example of a user equipment (UE) 500 in accordance with aspects of the present disclosure.

[0022] Figure 6 illustrates an example of a processor 600 in accordance with aspects of the present disclosure.

[0023] Figure 7 illustrates an example of a network equipment (NE) 700 in accordance with aspects of the present disclosure.

[0024] Figure 8 illustrates a flowchart of a method performed by a UE in accordance with aspects of the present disclosure. DETAILED DESCRIPTION

[0025] Beamforming is a technique in which an array of transmit antennas focuses the transmit power in a specific spatial direction by adjusting phases and amplitudes of symbols transmitted from its antenna elements. In this way the transmitter carries a maximized power to a target device at a specific direction and minimizes the interference imposed on other devices. If the target device has multiple antennas, it can similarly Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 5 perform beamforming by combining the received signals at its antennas with coefficients adjusted in phase and amplitude to maximize received power in a specific spatial direction. The two types of beamforming are referred to as transmit and receive beamforming, respectively. Transmit beamforming may involve transmitting one or more beam in a certain direction while receive beamforming may involve tuning a receiver to a certain direction.

[0026] Beamforming can be done in digital and analog domains, or a combination of both which is known as hybrid beamforming. Digital beamforming enables higher beam resolution as well as spatial multiplexing, but it requires a larger number of radio frequency (RF) chains, equal to the number of antenna elements and has high power consumption. When this number is high, digital beamforming is complex and expensive. On the other hand, analog beamforming can work with one RF chain at a time at the cost of lower beam resolution and spatial multiplexing.

[0027] The use of each beamforming type and their hybrid depends on the character of the communication scenario and its requirements. In lower bands where bandwidth is more scarce and where fewer antennas are employed at the transmit / receive array, digital beamforming offers higher spectral efficiency enabled by spatial multiplexing and therefore is preferred. In higher bands, where bandwidth is abundant and more transmit / receive antennas are employed (due to smaller wavelength and denser packing of more antennas), analog beamforming has lower cost and is typically preferred. In most scenarios an optimal trade-off between spatial resolution and cost / complexity is achieved by using hybrid beamforming.

[0028] When communicating with analog beams, it is important for the transmitter and receiver to agree on a pair of transmit / receive beams through which the channel enjoys a high aggregate power and therefore is suitable for communication. The process of obtaining such a beam pair and recovering it when lost is known as beam management (BM). In 5G NR, the beam pair acquisition part of BM is broadly carried out by “sweeping” a number of beam pairs, measuring the received power for each beam pair in terms of L1-RSRP, and reporting the best beam pair(s) and their received power(s) from the receiver to the transmitter. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 6

[0029] A new feature of enhanced massive multiple-input multiple-output (MIMO) in 5G NR is multi-transmission-and-reception-point (multi-TRP), in which a gNB uses more than one array of antennas located at generally different locations to transmit to a user equipment (UE). The TRPs can cooperate in a coherent fashion by sending the same data to the UE by coherent joint transmission (CJT) or transmitting different data, i.e., different layers, to the UE by non-coherent joint transmission (NCJT). In both ways, multi-TRP provides higher channel diversity, better interference management, and a more uniform channel quality to cell-center and cell-edge UEs.

[0030] With multi-TRP, downlink BM amounts to finding a group of transmit beams and a receive beam such that the aggregate channel of the transmit beams and the receive beam has high quality. The legacy BM framework is designed for a single transmitter and receiver and cannot be directly applied to multi-TRP. This is because measuring power by sweeping beams consecutively for each TRP consumes a long time. As an example, if M TRPs are each capable of forming N analog beams, and a UE is capable of forming K analog beams, the UE has to measure M×N×K received L1-RSRPs, each corresponding to one beam pair. This can be a large number especially when many TRPs are involved (M≫1).

[0031] A solution for the downlink BM problem with multi-TRP consists of extending the legacy P-1, P-2, P-3 procedure to multiple transmitters. In this case, first an initial beam pair is established between the UE and each of the TRPs. Then, by determining the beam pairs the network identifies a number of beam groups containing refined / adjusted beams, each of which corresponds to a different TRP. Finally, the UE measures L1-RSRP for each of these beam groups and reports a number of them with the highest L1-RSRP to the network.

[0032] In more detail, BM consists of a process of establishing, keeping and recovering a pair of beams between a transmitter and a receiver that together provide a channel with high quality. In downlink the transmitter is a gNB and the receiver is a UE, and in uplink the transmitter is a UE and the receiver is a gNB. The established beam pair in downlink may or may not be used for uplink, based on the property known as beam correspondence between downlink and uplink channels. Although the discussion in this disclosure is Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 7 primarily presented from the perspective of downlink BM, embodiments are not limited to downlink BM and can extend to uplink BM as well.

[0033] Conventional downlink BM consists of three procedures, known as P-1, P-2, P- 3.

[0034] In P-1, the UE establishes an initial beam pair with the gNB by exchanging initial access synchronization signal (SS) and random access channel (RACH) preamble. The gNB transmits an “SS burst” consisting of several SS blocks, where each block is associated with a different transmit beam. The UE receives SS burst sequentially with its receive beams, measures the L1-RSRP per beam pair and reports the index of the “best” transmit beam to the gNB by sending a RACH preamble on a RACH occasion associated with the SS block carried by that beam. The SS block beams are typically wide to cover a larger angular span when the UE is still in idle mode and therefore the initially acquired beam pair consists of wide beams.

[0035] In P-2, the gNB refines the transmit beam by transmitting a set of channel state information reference signals (CSI-RS) which are carried with narrower beams. These beams are chosen to cover the same angular span of the selected wide transmit beam in P-1, therefore attempting to refine the spatial focus of the transmit beam. At the same time, the UE measures the transmitted CSI-RS with a fixed receive beam. Then the UE reports the indices and L1-RSRPs of up to four strongest refined beams to the gNB.

[0036] In P-3, the gNB fixes a transmit beam and CSI-RS to the UE, while the UE sweeps its receive beams and measures L1-RSRP. The UE chooses the best receive beam based on these measurements.

[0037] One problem with such an approach is that there are an excessive number of candidate beam groups that the network has to transmit at P-2 in a multi-TRP environment. This is because there can be a large number of TRPs and each TRP may have a large number of candidate refined / adjusted beams to transmit with. The large number of candidate beam groups results in a large overhead in measurement and reporting.

[0038] Embodiments of the present disclosure relate to a low-complexity BM method for multi-TRP. Some implementations include two analog beam codebooks at both the Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 8 TRPs and the UE, where one codebook consists of “wide” beams and the other consists of “narrow” beams. Wide beams have lower spatial resolution and cover a larger spatial aperture, while narrow beams have higher spatial resolution and cover a smaller spatial aperture. While both codebooks may cover the same spatial span, the number of wide beams is less than that of narrow beams.

[0039] BM may be performed in three stages. In a first stage, each TRP sends reference signals (RS) to the UE by sweeping its wide transmit beams. The UE receives the transmitted RS by each wide beam using each of its wide receive combining beams. The UE uses these measurements to determine a set of narrow transmit beam groups which are then reported to the network.

[0040] In a second stage, the network transmits RS jointly by the narrow beams included in the beam group, for a set of beam groups that correspond to the set reported by the UE. The UE measures the L1-RSRP of the signal received for each beam group and reports an indication of a number of beam groups with the highest L1-RSRP to the network.

[0041] In a third stage, the network chooses one beam group and transmits RS over multiple symbols while the UE sweeps its narrow receive combining beams and chooses the one that receives the highest power.

[0042] As a part of the first stage, the UE may identify candidate narrow transmit beam groups from measurements on wide transmit / receive beams by exploiting channel sparsity. This reduces overhead because the number of wide beams at the transmitters and the receiver can be much lower than the number of narrow beams. The reporting of candidate narrow transmit beam groups from the UE to the network also suggests an efficient solution for BM in multi-TRP systems, where the number of candidate transmit beam groups is generally so high it is not feasible to sweep them all and choose the best group.

[0043] Embodiments of the present disclosure reduce the overhead associated with BM by reporting a set of candidate beam groups from the UE to the network in the first stage, which substantially limits the set of beam groups to be measured and reported and hence decreases overhead. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 9

[0044] Aspects of the present disclosure are described in the context of a wireless communications system.

[0045] Figure 1 illustrates an example of a wireless communications system 100 in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more NE 102, one or more UE 104, and a core network (CN) 106. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a NR network, such as a 5G network, a 5G-Advanced (5G-A) network, or a 5G ultrawideband (5G-UWB) network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G, for example, 6G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA), frequency division multiple access (FDMA), or code division multiple access (CDMA), etc.

[0046] The one or more NE 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the NE 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a network function, a network entity, a radio access network (RAN), a NodeB, an eNodeB (eNB), a next-generation NodeB (gNB), or other suitable terminology. An NE 102 and a UE 104 may communicate via a communication link, which may be a wireless or wired connection. For example, an NE 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

[0047] An NE 102 may provide a geographic coverage area for which the NE 102 may support services for one or more UEs 104 within the geographic coverage area. For example, an NE 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc.) according to one or Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 10 multiple radio access technologies. In some implementations, an NE 102 may be moveable, for example, a satellite associated with a non-terrestrial network (NTN). In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas may be associated with different NE 102.

[0048] The one or more UE 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples.

[0049] A UE 104 may be able to support wireless communication directly with other UEs 104 over a communication link. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

[0050] An NE 102 may support communications with the CN 106, or with another NE 102, or both. For example, an NE 102 may interface with other NE 102 or the CN 106 through one or more backhaul links (e.g., S1, N2, N2, or network interface). In some implementations, the NE 102 may communicate with each other directly. In some other implementations, the NE 102 may communicate with each other or indirectly (e.g., via the CN 106. In some implementations, one or more NE 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC). An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs). Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 11

[0051] The CN 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN 106 may be an evolved packet core (EPC), or a 5G core (5GC), which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management functions (AMF)) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc.) for the one or more UEs 104 served by the one or more NE 102 associated with the CN 106.

[0052] The CN 106 may communicate with a packet data network over one or more backhaul links (e.g., via an S1, N2, N2, or another network interface). The packet data network may include an application server. In some implementations, one or more UEs 104 may communicate with the application server. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the CN 106 via an NE 102. The CN 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server using the established session (e.g., the established PDU session). The PDU session may be an example of a logical connection between the UE 104 and the CN 106 (e.g., one or more network functions of the CN 106).

[0053] In the wireless communications system 100, the NEs 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communications). In some implementations, the NEs 102 and the UEs 104 may support different resource structures. For example, the NEs 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the NEs 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the NEs 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures). The NEs 102 and the UEs 104 may support various frame structures based on one or more numerologies. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 12

[0054] One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., ^^^^=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., ^^^^=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., ^^^^=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., ^^^^=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., ^^^^=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., ^^^^=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

[0055] A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames). Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

[0056] Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., ^^^^=0, ^^^^=1, ^^^^=2, ^^^^=3, ^^^^=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., OFDM symbols). In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing), a slot may include 12 Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 13 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., ^^^^=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

[0057] In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz – 7.125 GHz), FR2 (24.25 GHz – 52.6 GHz), FR3 (7.125 GHz – 24.25 GHz), FR4 (52.6 GHz – 114.25 GHz), FR4a or FR4-1 (52.6 GHz – 71 GHz), and FR5 (114.25 GHz – 300 GHz). In some implementations, the NEs 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the NEs 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data). In some implementations, FR2 may be used by the NEs 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

[0058] FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies). For example, FR1 may be associated with a first numerology (e.g., ^^^^=0), which includes 15 kHz subcarrier spacing; a second numerology (e.g., ^^^^=1), which includes 30 kHz subcarrier spacing; and a third numerology (e.g., ^^^^=2), which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies). For example, FR2 may be associated with a third numerology (e.g., ^^^^=2), which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., ^^^^=3), which includes 120 kHz subcarrier spacing.

[0059] Multi-TRP operation refers to the use of several TRPs to transmit or receive data in the network. The multiple TRPs are geographically separated and may correspond to current cell sites or access points in a distributed or cell-free antenna system. Advantages of multi-TRP include increased channel power due to coherent beamforming among several transmitters (or receivers), increased channel robustness against blockage and fading due to Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 14 spatial diversity and enhanced spatial multiplexing by sending different data layers from different transmitters.

[0060] In NR, multi-TRP operation in downlink consists of two broad schemes. The first scheme is (a) transmission of different data from multiple TRPs, which is known as non-coherent joint transmission (NCJT). This results in increased UE data rate due to spatial multiplexing and is beneficial for enhanced mobile broadband (eMBB) applications. In terms of scheduling, the data can be transmitted either as different layers of the same PDSCH using a single downlink control information (DCI) carried by a single physical downlink control channel (PDCCH) from one TRP or as different PDSCHs using multiple DCIs carried by multiple PDCCHs from multiple TRPs. NCJT is suited for use in lower bands, first because in higher bands it is difficult for the UE to simultaneously receive data from different directions, and second because the spectral efficiency gain given by NCJT is more helpful in lower bands than in higher bands. There is however no restriction on using NCJT in higher bands.

[0061] The second scheme is (b) transmission of the same data from multiple TRPs, for the purpose of enhancing channel reliability and beamforming gain. First, the same data can be transmitted on different times (time multiplexing) or different frequencies (frequency multiplexing), which is a way of repeating data so that in the case of severe blockage or fading in the channel of one TRP, data is received from a second TRP. This leads to ultra- reliable low latency communications (URLLC) benefits. In addition, the same data can be transmitted in the same resource set by multiple TRPs with close time and frequency synchronization which is known as coherent joint transmission (CJT). CJT increases the received power and beamforming gain, which is particularly suited to higher bands where power is limited.

[0062] Embodiments of the present disclosure provide a solution for determining a group of transmit beams, each transmitted by a TRP and a receive beam at the UE, such that the combined channel between the TRPs and the UE has high quality. A beam may be determined by a beamsteering vector consisting of phase and amplitude coefficients with which each array antenna port transmits or receives a signal. If the array has ^^^^ ports, thenthe beamsteering vector may be a vector ^^^^ ∈ ℂ^^^^. Consider the case in which a signalAttorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 15 carrying a symbol ^^^^ is impinging the array with an angle of arrival (AoA) ^^^^ and the array combines the signal with the vector ^^^^. In the absence of noise, the received signal is given by ^^^^(^^^^) = √^^^^^^^^^^^^^^^^(^^^^)s, where ^^^^ denotes the symbol power and ^^^^(^^^^) ∈ ℂ^^^^ is the array^^^^. Assuming ^^^^ = 1 and ^^^^ = 1 for simplicity, the received power asby ^^^^(^^^^; ^^^^) = ‖^^^^^^^^^^^^(^^^^)‖22. The same holds for thetransmitted power of an array with ^^^^ antenna ports.

[0063] The purpose of beamforming is to focus the received / transmitted power in a region around a certain AoA or angle of departure (AoD). As an example, the beams can be chosen based on discrete Fourier transform (DFT) vectors which are associated with a uniformly spaced grid of AoAs / AoDs. The half power beam width (HPBW) is defined as the angular span in which the magnitude of the radiation pattern (denoted here by ^^^^(^^^^; ^^^^))decreases by 3dB from the peak of the main beam.

[0064] The terms “wide” and “narrow” beams in this disclosure refer to a wide beam having a larger HPBW than a narrow beam. To cover a certain angular span, an array uses fewer wide beams than narrow beams.

[0065] The following discussion relates to downlink BM of a network consisting of ^^^^ TRPs and a single UE. For simplicity of explanation, the following discussion may assume that each TRP is equipped with the same number of^^^^^^^^^^^^2 dual-polarized antennas and the UE is equipped with^^^^^^^^^^^^2 dual-polarized antennas. Ina UE and a TRP each has two sets ofvector codebooks.

[0066] Each TRP may use one codebook representing wide transmit beams denoted by ℱ(1) (1)^^^^ … ^^^^(1)and another codebook narrow transmit beams denotethe wide and narrow transmit beam codebooks may be the same across the TRPs, such that ℱ(1) ( )^^^^ = ℱ (1) and ℱ 2^^^^ = ℱ (2) for all ^^^^ = 1, … ,^^^^. The dimension of the elements of eachAttorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 16 codebook may be equal to the number of transmit antenna ports at the TRP, namely ^^^(^^^^)^^^^^,^^^^∈ ℂ^^^^^^^^^^^^ for all ^^^^, ^^^^,^^^^.

[0067] The UE may use one codebook representing wide receive beams denoted by ^^^^(1) ≜�^^^^(1)(1)1, … ,^^^^^^^^(1)� and another codebook representing narrow receive beams denoted ^^^^denote the number of wide and narrow the elements of each codebook is equal tothe number of receive antenna ports at the UE, namely ^^^^(^^^^)^^^^ ∈ ℂ^^^^^^^^^^^^ for all ^^^^, ^^^^.

[0068] As an example, wide beams may correspond to beams used for transmitting or receiving a synchronization signal block (SSB) from a TRP to the UE in idle mode. These beams may cover a larger angular span and are fewer in number compared to narrow beams. On the other hand, narrow beams may correspond to refined beams used for transmitting / receiving CSI-RS from a TRP to the UE in connected mode. These beams are more focused on a smaller angular span and are more numerous than wide beams. Therefore the number of narrow beams is more than that of wide beams, i.e., ^^^^(2)(1)^^^^ ≥ ^^^^^^^^and ^^^^(2) ≥ ^^^^(1)^^^^. In addition, the discussion assumes without loss of generalityvectors have unit norm, such that�^^^(^^^) ( )^^^^^^,^^^^� =�^^^^ ^^^^^^^^ � = 1 for all ^^^^, ^^^^,^^^^.

[0069] The transmission andcodebooks may be available at the UE, but in some embodiments the network may not have access to the reception beam codebooks ^^^^(1)and ^^^^(2). The transmission beam codebooks may be either explicitly or implicitlya configuration message from the network to the UE. For example, the network may transmit parameters to the UE, and the codebooks may be uniquely determined using the transmitted parameters. The configuration message may be, for example, a CSI configuration setting. The codebooks or their parameters can be alternatively pre- configured at the UE.

[0070] In some embodiments, a UE may use one codebook rather than two which implies ^^^^(1) = ^^^^(2). For example, a UE may only use wide beams because in downlinkmulti-desirable for the UE to be able to simultaneously receive signals from Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 17 multiple directions, and the orientation of a UE may change rapidly in a mobility situation. On the other hand, it can be beneficial to have both narrow and wide beams for transmission at the TRPs because wide beams can be used to quickly establish an initial beam pair with the UE, while narrow beams focus power in a certain direction and cause less interference on other UEs.

[0071] As an example, wide and narrow beams can be designed as follows. In the example, ^^^^^^^^beam vectors of dimension ^^^^ are provided, where ^^^^^^^^can be the number of wide beams or narrow beams and where ^^^^ can be equal to the number of transmit antennas ports ^^^^^^^^^^^^or the number of receive antenna ports ^^^^^^^^^^^^. This can be accomplished using so- called “balance beams” as an example. Let Ψ denote the angular aperture of the transmit or receive antenna array, which includes all spatial directions to which the array can send power. For a planar array, Ψ is a set of 2D azimuth-zenith angle values. Define a uniformgrid over Ψ with ^^^^^^^^ points and denote these points by {^^^^1, … ,^^^^^^^^^^^^}. Then define Δ^^^^ as avector of the same dimension as ^^^^^^^^. This vector indicates a width parameter for the beam in each of the angular (e.g. azimuth and zenith) directions. To obtain the beam vectors the following optimization problem is solved: ^^^^^^^^(1)+ ^^^^^^^^(1) (2^^^^^^^^(2)+ ^^^^^^^^2)^^^^⋆2 ^^^^ = ^^^^^^^^^^^^ ^^^^^^^^^^^^ ^^^^^^^^ ^^^^^^^^Where ^^^^ is the optimization variable vector of dimension ^^^^ / 2, ^^^^^^^^(^^^^) denotes the ^^^^-th element of ^^^^^^^^, ^^^^ (^^^^) is the ^^^^-th element of ^^^^, Δ^^^^(^^^^) the ^^^^-th element of Δ^^^^and ^^^^(^^^^) is the array response vector at an angle ^^^^ of dimension ^^^^ / 2. This problem can be solved by finding the eigenvector corresponding to the largest eigenvalue of the positive-semidefinite matrix: ^^^^^^^^(1)+Δ^^^^(1)2^^^^^^^^(2)+Δ^^^^(2)2^^^^ ).Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 18

[0072] After solving this problem, the ^^^^-th beam is given by the�^^^^^^^^� which is a vector of dimension ^^^^. The beamwidth can be controlled by the vector Δ^^^^. For example, thewidth of wide and narrow beams can have a relationship as Δ^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = ^^^^Δ^^^^ where ^^^^ > 1is a larger than 1 scalar. The number of beams can be set by the variable ^^^^^^^^, and beamdirections can be controlled via setting the grid points {^^^^1, … ,^^^^^^^^^^^^}. However, this is justone example of how wide and narrow beams can be designed, and the network and UE can use other examples for wide and narrow beams.

[0073] Embodiments of a BM method for multi-TRP can be described with respect to three stages. In stage 1, each TRP may transmit a “burst” of reference signal “blocks”, where each block is transmitted using a different wide beam from the set ℱ(1)^^^^. Therefore the burst includes at least ^^^^(1)^^^^blocks, where each block spans aof symbols and subcarriers. For the reference signal can be an SS where each SS block spansfour OFDM symbols and 240 subcarriers and an SS burst set can contain 4, 8, and 64 SSblocks in FR1 (≤ 3 GHz), FR1 ([3 − 7.125] GHz) and FR2 (mmWave), respectively. TheUE may receive each RS block by applying each of its receive wide beams from the set ^^^^(1). With digital beamforming, multiple receive beams can be applied simultaneously, with analog beamforming the UE may sweep its receive beams and apply each receive beam to a different receive symbol.

[0074] Figure 2 illustrates an example of a wireless communication system that supports beam management in accordance with aspects of the present disclosure. For example, the wireless communication system may support beamformed communication between one or more of a TRP 102a, a TRP 102b, and a UE 104, each of which may be examples of corresponding UE or NE as described herein with reference to Figure 1. The TRP 102a may transmit a set of one or more reference signals over a set of one or more wide beams (also referred to herein as wide transmit beams). In the example of Figure 2, the TRP 102a may transmit a reference signal (also denoted as RS in Figure 2) on each of four wide transmit beams. For example, the TRP 102a may transmit RS-1 over a wide transmit beam 301, RS-2 over a wide transmit beam 302, RS-3 over a wide transmit beam 303, and RS-4 over a wide transmit beam 304. Additionally, or alternatively, the TRP 102b Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 19 may transmit a set of one or more reference signals over a set of one or more wide beams. In the example of Figure 2, the TRP 102b may transmit a reference signal on each of four wide transmit beams. For example, the TRP 102b may transmit RS-5 over a wide transmit beam 305, RS-6 over a wide transmit beam 306, RS-7 over a wide transmit beam 307, and RS-8 over a wide transmit beam 308. In some cases, the beamformed communication by one or more of the TRP 102a or the TRP 102b may be in an analog domain, in which case the beamformed communication is performed sequentially (e.g., in time). The sequential beamformed communication is illustrated in Figure 2 with dashed lines.

[0075] The UE 104 may receive a set of one or more reference signals over a set of one or more wide beams (also referred to herein as wide receive beams). In the example of Figure 2, the UE 104 may receive a reference signal on each of three wide receive beams. For example, the UE 104 may receive a corresponding reference signal from one or both of the TRP 102a or the TRP 102b over each of a wide receive beam b1, a wide receive beam b2, and / or a wide receive beam b3. The UE 104 may perform a beam sweep of the set of one or more wide receive beams of the UE 104. For example, in accordance with the beam sweep, the UE 104 may sequentially receive beamformed communication (e.g., in the following order) from each of the TRP 102a and TRP 102b. For example, reference signals RS-1 to RS-4 from the TRP 102a may be firstly received by the wide receive beam b1 of the UE 104, the reference signals RS-1 to RS-4 from the TRP 102a may be secondly received by the wide receive beam b2 of the UE 104, and the signals RS-1 to RS-4 from the TRP 102a may be thirdly received by the wide receive beam b3 of the UE. Additionally, or alternatively, the UE 104 may subsequently perform the beam sweep to receive the reference signals RS-6 to RS-8 associated with the TRP 102b via the three wide receive beams b1 to b3. In some other examples, one or more of the TRP 102a or the TRP 102b may transmit reference signals using different numbers of wide transmit beams, and the UE 104 may also receive the reference signals using different numbers of wide receive beams. It should be understood that other beam sweep operations (e.g., beam sweep sequences) other than the one described above may be used to support beamformed communication. Additionally, it should be understood that although the above examples are described with reference to two TRPs 102, the beam operations (e.g., beam sweeps) may be supported for more than two TRPs, etc. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 20

[0076] When digital beamforming is employed, a TRP 102 may transmit reference signals over its wide beams at the same time, and each TRP 102 may transmit the beams in sequence such that only one TRP 102 transmits reference signals at a time. For example, TRP 102a may transmit wide beams 301, 302, 303 and 304 at the same time, and after those beams are transmitted, TRP 102b may transmit wide beams 305, 306, 307 and 308 at the same time. In an embodiment, all TRPs 102 may sweep their wide beams periodically, which also serves purposes other than beam management, such as enabling initial access for UEs 104 that enter the network. For example, in NR a synchronization signal (SS) burst set may be transmitted with a 20 ms periodicity. During the transmission of each SS burst set, the TRP 102 sweeps a number of beams. In an embodiment, each TRP 102 periodically transmits reference signals by sweeping its wide beams. Each TRP 102 may be associated with a single or multiple cells. The network may determine which TRPs 102 belong to the set of TRPs that transmit wide beams to a particular UE 104.

[0077] The TRPs 102 may use a first set of reference signal resources to transmit the wide beam reference signals. For example, in one embodiment, the reference signal is a set of SSs which are transmitted over physical broadcast channel (PBCH) resources. In another embodiment, the reference signal comprises a set of tracking reference signals (TRSs). In an embodiment, the reference signal is a TRS corresponding to a channel state information (CSI) RS resource set configured with a tracking parameter. Another example of reference signal resources is a first set of non-zero power (NZP) CSI-RS resources. The wide beam transmissions may comprise one or more of these reference signals and reference signal resources, or other reference signals and resources as known in the art.

[0078] The received signal corresponding to the ^^^^-th transmit wide beam of TRP ^^^^ and received by the ℓ-th wide beam of the UE 104 can be expressed as ^^^^ = ^^^^ ^^^^(1)^^^^ℓ ^^^^ ^^^^^(1)^^^,^^^^^^^(1)^^^^^^^^,^^^^,ℓ � ^^^^ ^^^^ ^^^^^,^^^^ + ^^^^ℓ^^^^^^^^,^^^^(1)symbol, ^^^^ ^^^^^^^^,^^^^ ∈ ℂ ^^^^^^^^ isadditive noise, and ^^^^^^^^ ∈ ℂ^^^^^^^^^^^^×^^^^^^^^^^^^ is the channel matrix coefficients of the channelbetween TRP ^^^^ and the UE 104. Without loss of generality, we assume the reference Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 21symbols to be equal to ^^^^^^^^,^^^^ = 1 for all ^^^^,^^^^. The received signal for all transmit andreceive beams for TRP ^^^^ can be represented in matrix form as^^^^^^^^ =�^^^^^^^^^^^^ (1)^^^^^^^^ (1)^^^^^^^^^^^^ + ^^�^^^^^^^^^^ ∈ ℂ ^(^^1^)×^^^^(1)^^^^, (2)combining vectors, ^^^^is the matrix of transmit beamsteering vectors, and ^^�^^elements given by [^^�^^ ] = ^^(1)^^^^^^^^ ℓ,^^^^ ^^ℓ^^^^^^^^,^^^^.

[0079] After obtaining the measurements ^^^^^^^^,^^^^ = 1, … ,^^^^, the UE 104 may estimatethe channel coefficient matrices ^^^^ ,^^^^ = 1, … ,^^^^.may beusing one of the following exemplary channel models. One example channel model is the dual-polarized MIMO channel model. In this model, the dual-polarized multi-path MIMO channel matrix can be modeled as ^^^^^^^^^^^^^^^^^^^^where ^^^^ is the^^^^ 2×2^^^^ ∈ ℂ is aof coefficients between horizontal / vertical polarizations of the transmitter antenna element and the horizontal / vertical polarizations of the receiver antenna element, ^^^^^^^^,^^^^and ^^^^^^^^,^^^^are the angle of arrival (AoA) and the angle of departure (DoA) of path ^^^^, respectively. Here ^^^^(⋅) and ^^^^^^^^(⋅) are array response vectors of the UE 104 and TRP ^^^^, respectively defined as ^^^^ ^^^^2^^^^ ^^^^2^^^^^ ^^^^ �Δ^^^^^^^^^^^^�Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 22 ^^^^ ^^^^2^^^^ 1 ^^^^2^^^^′^ ^^^^ �Δ ′^^^^^^^^^^^^ ,^^^^�^^^^^^^(^^^^) =�^^^^^^^^ �Δ^^^^,1 ,^^^^� , … , ^^^^ ^^^^, 2� Where ^^^^ denotesof element ^^^^ of the UE 104 antenna array, Δ′^^^^,^^^^denotes the 3D coordinates of the ^^^^-th element of the antenna array of TRP ^^^^ and ^⋅,⋅^ denotes Euclidean inner product.

[0080] If the antenna array is a uniform linear array (ULA), the “effective” AoA or AoD is a scalar angle, while if the antenna array may be a uniform planar array (UPA), the effective AoA or AoD may be a two-dimensional vector consisting of azimuth and zenith angles with respect to the array plane. The formulas above include these special cases.

[0081] In a MIMO multipath channel with many transmit and receive antennas, the number of paths ^^^^^^^^is typically much smaller than the channel dimensions, especially in higher bands where pathloss attenuation is stronger, i.e., ^^^^^^^^ ≪ ^^^^^^^^^^^^^^^^^^^^^^^^. This is known aschannel sparsity. Embodiments of the present disclosure may use channel sparsity to estimate narrow beams corresponding to the wide beams transmitted by the TRPs.

[0082] To exploit channel sparsity, the channel can be described in terms of a linear combination of wavefronts corresponding to a dense grid of AoAs and AoDs. To do this, two dense angular grids are defined corresponding to AoAs and AoDs as{^^�^^^^^^} ^^^^^^^^^^^^=1and �^^�^^� ^^^^^^^^^^^^=1 , where ^^^^^^^^ ≫ ^^^^^^^^^^^^ / 2 and ^^^^^^^^ ≫ ^^^^^^^^^^^^ / 2. Typical values for these^^^^^^^^or 3^^^^^^^^^^^^ / 2 and ^^^^^^^^ = 2^^^^^^^^^^^^ / 2 or 3^^^^^^^^^^^^ / 2. Then the channel is expressed^^^^^^^^ = ∑^^^^^^^^^^^^=1 ∑^^^^^^^^^^^^=1 ^^^^′^^^^,^^^^,^^^^ ⊗ (^^^^(^^�^^^^^^) ^^^^�^^�^^^^^^^^^^�) , (4)associated angle of arrival ^^�^^^^^^ and angle of departure ^^�^^^^^^.

[0083] The main difference between the expressions in Equations (3) and (4) is that the non-linear dependence of the channel on AoAs and AoDs is removed. Also, the same grid of AoDs can be used for all TRPs because the vectors ^^^^�^^�^^^^^^�span the ^^^^^^^^^^^^ / 2-dimensionalAttorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 23 space. This expression may be further simplified by defining an AoA-AoD grid as {^^�^^^^^^}^^^^^^^^^^^^=1 ×�^^�^^^^^^� ^^^^^^^^^^^^=1 = {^^^^^^^^ =�^^�^^^^^^ ,^^�^^^^^^�,^^^^ = ^^^^^^^^(^^^^ − 1) + ^^^^, ^^^^ = 1, … ,^^^^^^^^, ^^^^ = 1, … ,^^^^^^^^} and(5)with reduced

[0084] When exploiting channel sparsity a measurement operator may be defined as: ^^^^ ^^^^(1)×^^^(1)( )^^^^:ℂ ^^^^^^^^×^^^^^^^^^^^^ → ℂ^^^^^^^^ ^^^^^ ,^^^^ →�^^^ (1)^^^^1^^^^^^^^^ ^^^^^^^^^^^^which maps theby wide beams atTRP ^^^^ and the UE 104, ^^^^^^^^ = ^^^^^^^^(^^^^^^^^) + ^^�^^^^^^ from Equation (2). If all TRPs use the samewide transmit beams andtransmit power then we have ^^^^1 = ⋯ = ^^^^^^^^. Sincethe channel is sparse, we may estimate it from the measurements by inthe coefficients ^^^^′^^^^,^^^^ ,^^^^ = 1, … ,^^^^^^^^^^^^^^^^. This can be generally formulated as the followingoptimizationfor ^^^^ = 1, … ,^^^^:^^^^^^^^^^^^^^^^2 ^^^^ ^^^^ ^^^^2where ‖ ⋅ ‖which countsnumber of non-zero elements in a vector, and ^^^^ asparsity order parameter. constraint enforces that no more than ^^^^0matrix coefficients have non-zero elements.

[0085] There are other ways of promoting sparsity in the estimated channel coefficients by solving convex optimization problems, for example by using ℓ1-norm minimization and its variants. ℓ1-norm minimization does not enforce a strictly sparse solution but its optimized solution has a few coefficients with large values and the rest of the coefficients close to zero. Another approach is to use a greedy algorithm which sequentially finds non- Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 24 zero coefficients that contribute most to the measurements. One such algorithm is known as orthogonal matching pursuit (OMP).

[0086] A generalized form of OMP may be used that is adjusted to recover matrix coefficients (rather than scalar coefficients), because of its low complexity. This method may be implemented using the following steps: 1. Input: Matrices ^^^^^^^^, {^^^^^^^^}^^^^^^^^^^^^^^^^^^^^=1, the operator ^^^^^^^^(⋅), sparsity order ^^^^02. Set the “residue matrix” as ^^^^0 ← ^^^^^^^^3. Set the “index set” as Λ0 = ∅. This set will store the indices of non-zeromatrix coefficients. 4. Set the iteration counter ^^^^ = 1.5. Find the index of the element in {^^^^^^^^}^^^^^^^^^^^^^^^^^^^^=1that has the highest correlation with the measurements, i.e.^^^^^^^^ = arg^^^^ m∉ Λax|^^^^^^^^^−1,^^^^^^^^(^^^^^^^^)^|. ^^^^−16. Update theUpdate the coefficients estimate: 22^^^^ = ^^^^ .The optimization at this step is a regression problem that can be efficiently solved. 8. Compute the residue matrix as ^^^^ ← ^^^^ ^^ −(^^^^) ^^^^ ^^ � ^^^^^^^^ ⊗ ^^^^^^^^9. Set ^^^^ ← ^^^^ + 1go ^^^^0.Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 25 10. Output: Estimated coefficients�^^�^^^^^^,^^^^ , ^^^^ = 1, … ,^^^^^^^^^^^^^^^^�.

[0087] This algorithm may be run for all1, … ,^^^^. denoting the optimizedcoefficients from running the algorithm above by the estimated channel after running the algorithm above as ^�^^^^^^^ =�^^�^^^^^^,^^^^ ⊗ ^^^^^^^^.^^^^

[0088] The number of^^^^0which is the assumed sparsity order. If it is known that the channel is very sparse, as is the case in higher bands, ^^^^0maybe set to a small value which makes the algorithm above run fast. In the case where ^^^^0 = 1,the algorithm runs for only one iteration.

[0089] After estimating the channel between each TRP and the UE, the UE 104 uses the channel estimates to estimate the received power when narrow beams are applied at the transmitters and the receivers. Similar to Equation (1), the signal transmitted by the ^^^^-th narrow transmit beam from TRP ^^^^ and received by the ℓ-th narrow receive beam at the UE 104 can be expressed as: ^^^^′( )^^^^,^^^^,ℓ =�^^^^^^′^^ ^^^^2 ^^^^ℓ ^^^^^^^^^^^^^(2)^^^,^^^^^^^^^′^^^,^^^^+ ^^^^(2)^^^^ℓ ^^^^^′^^^,^^^^Where ^^^^′is the^^^^ of TRP ^^^^, ^^^^^^^^is transmit power of TRP ^^^^ in sending the reference signal and ^^^^′is a noisethe UE 104 does not have direct access to ^^^^^^^^, it will use the estimated channel to compute the received power for each pair of narrow transmit and receive beams, given by ^^^^^^^^,ℓ,^^^^ = ^^^ ′(2)^^^^^^^^^ ‖^^^^ℓ ^�^^^(2)^^^^ ^^^^^^^^,^^^^‖2

[0090] After estimatingthe UE 104 can use this information to inform the network how the transmit beams should be refined. In the legacy BM framework, the UE 104 reports an indication of the best transmit wide beam to the network. In beam establishment during initial access the indication is reported implicitly: each SS block is associated with a corresponding random access occasion and a preamble. On the other hand, each SS block is associated with a different beam. By sending a random Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 26 access transmission on a specific occasion, the UE 104 can inform the network which transmission beam it prefers, because that occasion is exclusive to one SS block corresponding to that transmission beam.

[0091] For multi-TRP transmission this amounts to reporting one beam per TRP 102. However, refining beams using legacy processes will induce a large overhead since each TRP has to sweep a number of narrow beams that together cover the spatial range of their reported beam.

[0092] Instead, in embodiments of the present disclosure the UE 104 utilizes the information obtained by estimating the power of narrow beam pairs and may report an indication of a number of candidate “beam groups” that may be transmitted by the network in the next round.

[0093] A beam group includes a set of beams, each transmitted from a respective TRP 102. To report candidate beam groups, the UE 104 may first determine the receive wide beam that receives the highest total power from transmitted beams based on the UE 104 estimated powers. The index of this receive beam may be expressed as ℓ⋆ = arg max�^^^^^^^^,ℓ. ℓ,^^^^

[0094] The UE 104 may report antransmit beams that can be received by the beam ℓ⋆. Two examples of reporting an indication are as follows.

[0095] In a first example, the UE 104 transmits indices of ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^beams with the largest estimated power per TRP. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^may be kept small to limit the reporting overhead,e.g. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = 1 or 2. These beams can be selected by sorting the set {^^^^^^^^,ℓ⋆,^^^^,^^^^ =1, … ,^^^^(2)^^^^} for each ^^^^ and obtaining the indices of the ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^The indices of the ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^may be referred to as beam identifiers which are received by the UE 104. This kind of reporting gives the network the flexibility to choose beam groups of arbitrary size based on its capabilities and constraints such as scheduling. For example, when a TRP 102 is using a specific beam for transmission to another UE 104, the network may decline to include that beam in a beam group. In such an embodiment, the UE 104 may transmit an Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 27 indication which separately indicates at least one candidate narrow beam of each TRP 102 of a set of TRPs.

[0096] In a second example, the UE 104 reports a number of ^^^^ beam groups ^^^^(^^^^)1 , … ,^^^^ (^^^^)^^^^^^^^�, ^^^^ = 1, … ,^^^^� where ^^^^^^^^ ≤ ^^^^ is the number of beams within the group and^^^^, ^^^^. The criteria for choosing these beam groups can be theℓ⋆from the beams included in the group. ^^^^ groups with thesum power be reported to the network. In such an embodiment, theUE 104 may transmit an indication to the network which indicates a plurality of beam groups, each beam group comprising candidate narrow beams associated with respective TRPs 102 of the set of TRPs.

[0097] The second example can induce larger overhead compared to the first example, but it may send more information to the network on which beam groups potentially carry the most power. To provide this flexibility in the first example, the UE 104 can additionally send an indication of the estimated power values for each reported beam, or an indication of the ordering of estimated powers for the reported beams. In this way the network can decide which beams to include in a beam group based on which beams transmit the highest power.

[0098] After receiving an indication of the beam groups or an indication of individual beams for each TRP 102 and potentially their estimated power values or estimated power ordering, the network performs the second stage. In this stage, the network transmits a set of beam groups jointly from its TRPs, where each beam group is associated with a part of a reference signal resource set.

[0099] The specific beam groups transmitted by the network may be different from the beam groups reported by the UE 104. For example, the network can include other beams or exclude some of the beams in a group or in general can choose to transmit an entirely different beam group not included in the set of beam groups reported by the UE 104 due, for example, to scheduling constraints. However, in some embodiments, most or all of the beam groups transmitted to the UE 104 include beams reported from the UE 104 to the network. In some instances, the beam groups transmitted by the network may be the same Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 28 as the beam groups reported by the UE 104 to the network. The network may prioritize the beam groups reported by the UE 104 for transmitting beam groups to the UE 104.

[0100] The UE 104 may use the fixed wide beam ℓ⋆discussed above to receive the reference signals from the beam groups. In an embodiment, for each beam group, the UE104 measures the received power and then reports an indication of up to ^^^^^^^^^^^^reference signals, each associated with a beam group, to the network.

[0101] The UE 104 may use a wide receive beam to receive beam groups from TRPs 102 so that the UE 104 can receive beams from more directions, which can be helpful to measure and compare received powers from different transmission beam groups. If a narrow beam is used, the UE 104 may receive power from fewer directions.

[0102] Figure 3 illustrates an example of a UE 104 receiving narrow beam groups (also denoted as BG in Figure 3) from TRPs 102 in accordance with aspects of the present disclosure. In the example of Figure 3, the UE 104 receives four different beam groups BG 1, BG 2, BG 3 and BG 4 from TRP 102a and TRP 102b. Each of the beam groups BG 1, BG 2, BG 3 and BG 4 comprises one narrow beam (which may also be referred to as narrow transmit beams) from each TRP in a set of TRPs 102 that are transmitting beam groups to the UE 104. While Figure 3 only shows two TRPs 102, a larger number of TRPs may transmit narrow beams in the beam groups. That is, each beam group may comprise at least one narrow beam from each of a plurality or set of TRPs 102.

[0103] The narrow beams in beam groups BG 1, BG 2, BG 3 and BG 4 may comprise reference signals transmitted on a second set of reference signal resources. The second set of reference signal resources may be different from those which are used for wide beam transmissions from the TRPs 102 as seen in Figure 2. Examples of the reference signal resources used for the narrow beam transmissions in Figure 3 include a set of NZP CSI-RS resources, a set of reference signal resources configured with a joint transmission parameter, a set of demodulation reference signals (DMRSs), or a combination of these resources. Embodiments are not limited to these specific examples.

[0104] In the embodiment shown in Figure 3, the UE 104 receives narrow beams in beam groups BG 1, BG 2, BG 3 and BG 4 from the TRPs 102 using a wide beam b2. In the Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 29 analog domain, a first TRP 102a transmits one narrow beam of a beam group BG 1 and a second TRP 102b transmits the second narrow beam of beam group BG 1 at the same time so that UE 104 receives the narrow beams from both TRPs simultaneously. Each narrow beam group BG 1, BG 2, BG 3 and BG 4 may be cycled in sequence in the time domain until all beam groups have been transmitted. While only four beam groups are shown in the example of Figure 3, the number of beam groups can be larger or smaller than four.

[0105] In some embodiments, the network may exclude one or more of the TRPs 102 reported by the UE 104 from the TRPs that actually transmit the narrow beam groups. Accordingly, the number of TRPs 102 that transmit narrow beam groups, e.g., a second set of TRPs, may be lower than the number of TRPs associated with the candidate beams reported by the UE 104 to the network.

[0106] In addition, the UE 104 may report an indication of the received power from each reference signal. This power may be the aggregate received power from all the beams in a beam group. The power can be measured, for example, as the L1-RSRP of the received combined signal transmitted from the beams in the beam group. The reporting of received power may be the same as or similar to the legacy beam management specification, wherethe UE reports the L1-RSRP of the strongest beam group and then for each of the ^^^^^^^^^^^^ − 1reported beam groups, the UE reports the difference between the L1-RSRP received from that group and the L1-RSRP of the strongest beam group.

[0107] In some embodiments, each beam group of the one or more beam groups is transmitted over a distinct set of time / frequency resources on a slot / RB layout, such that two different beam groups are transmitted over different time resources, frequency resources, or a combination thereof.

[0108] In an embodiment, the UE transmits a CSI report comprising at least one of a resource indicator associated with a selected beam, a received power of a corresponding reference signal or a received signal to interference plus noise (SINR) of the corresponding reference signal. After receiving feedback from the UE, the network designates a beam group to be used for downlink transmission. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 30

[0109] Figure 4 illustrates an example of selecting a receive beam for communicating with TRPs 102 in accordance with aspects of the present disclosure. After the network has designated at least one beam group for downlink communications, the UE 104 may determine a receive beam for receiving downlink transmissions from multiple TRPs 102 while the transmit beam group is fixed. In the example of Figure 4, only two TRPs 102 are shown, but it should be understood that the number of TRPs may be larger than two. The UE 104 determining a receive beam on which to receive downlink transmissions from a plurality of TRPs 102 may be referred to as the third stage.

[0110] In this stage, the UE 104 may be configured with a set of downlink reference signals that are transmitted by the same beam group. As noted above, a beam group includes at least one narrow beam respectively associated with each TRP 102 of a set of TRPs.

[0111] In the embodiment shown in Figure 4, the UE 104 sweeps its receive beams b1, b-2, b-3 and b4, measuring the received reference signals and chooses the receive beam with the highest L1-RSRP. In various embodiments, the UE 104 may sweep different sets of beams. For example, the UE 104 may sweep the wide receive beams ^^^^(1), or the narrow beams ^^^^(1)or both of ^^^^(1)and ^^^^(2), or a subset of beams that coversspan of the3. Depending on the direction of the transmit beam group and the received power, the UE 104 may establish a connection using a wide or a narrow beam.

[0112] In some embodiments, the UE 104 may skip one or more aspect of determining receive beams as described above. For example, the UE 104 may use the same wide beam used to measure beam groups from the TRPs 102 to measure subsequent downlink transmissions from those TRPs.

[0113] In some embodiments, aspects of the various steps described above may be combined. For example, transmitting / receiving beam groups as shown in Figure 3 (stage two) may be combined with determining a receive beam for the UE 104 as shown in Figure 4 (stage three). In such an embodiment, the UE 104 may sweep a set of receive beams corresponding to the one or more beam groups transmitted over different time and / or Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 31 frequency resources. In one example, the one or more beam groups are transmitted with repetition over a plurality of time slots, wherein the UE 104 applies a distinct receive beam in each slot of the plurality of time slots. The UE 104 may report an index of a selected beam group subsequent to the plurality of time slots, wherein the UE also selects a receive beam to be associated with the selected beam group.

[0114] After determining the best receive beam, the UE 104 may report the receive beam index to the network. This can be useful, for example, in a subsequent uplink transmission in the presence of beam correspondence. In that case, the best receive beam may also be used as the best transmit beam by the UE 104 in uplink and the network will therefore know about the UE’s transmit beam.

[0115] Figure 5 illustrates an example of a UE 500 in accordance with aspects of the present disclosure. The UE 500 may include a processor 502, a memory 504, a controller 506, and a transceiver 508. The processor 502, the memory 504, the controller 506, or the transceiver 508, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

[0116] The processor 502, the memory 504, the controller 506, or the transceiver 508, or various combinations or components thereof may be implemented in hardware (e.g., circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

[0117] The processor 502 may include an intelligent hardware device (e.g., a general- purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof). In some implementations, the processor 502 may be configured to operate the memory 504. In some other implementations, the memory 504 may be integrated into the processor 502. The processor 502 may be configured to execute computer-readable instructions stored in the memory 504 to cause the UE 500 to perform various functions of the present disclosure. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 32

[0118] The memory 504 may include volatile or non-volatile memory. The memory 504 may store computer-readable, computer-executable code including instructions when executed by the processor 502 cause the UE 500 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such the memory 504 or another type of memory. Computer-readable media includes both non- transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

[0119] In some implementations, the processor 502 and the memory 504 coupled with the processor 502 may be configured to cause the UE 500 to perform one or more of the functions described herein (e.g., executing, by the processor 502, instructions stored in the memory 504). For example, the processor 502 may support wireless communication at the UE 500 in accordance with examples as disclosed herein. The UE 500 may be configured to support a means for receiving a configuration message for a beam management procedure, receiving first reference signals over a first set of reference signal resources in wide beam transmissions from a plurality of transmission-reception points (TRPs), determining at least one candidate narrow beam of each TRP of a set of TRPs of the plurality of TRPs, and transmitting a first indication indicating the at least one candidate narrow beam of each TRP of the set of TRPs to a network entity.

[0120] The controller 506 may manage input and output signals for the UE 500. The controller 506 may also manage peripherals not integrated into the UE 500. In some implementations, the controller 506 may utilize an operating system such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some implementations, the controller 506 may be implemented as part of the processor 502.

[0121] In some implementations, the UE 500 may include at least one transceiver 508. In some other implementations, the UE 500 may have more than one transceiver 508. The transceiver 508 may represent a wireless transceiver. The transceiver 508 may include one or more receiver chains 510, one or more transmitter chains 512, or a combination thereof. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 33

[0122] A receiver chain 510 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 510 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 510 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. The receiver chain 510 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 510 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

[0123] A transmitter chain 512 may be configured to generate and transmit signals (e.g., control information, data, packets). The transmitter chain 512 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM). The transmitter chain 512 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 512 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0124] Figure 6 illustrates an example of a processor 600 in accordance with aspects of the present disclosure. The processor 600 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 600 may include a controller 602 configured to perform various operations in accordance with examples as described herein. The processor 600 may optionally include at least one memory 604, which may be, for example, an L1 / L2 / L3 cache. Additionally, or alternatively, the processor 600 may optionally include one or more arithmetic-logic units (ALUs) 606. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses). Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 34

[0125] The processor 600 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 600) or other memory (e.g., random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), static RAM (SRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase change memory (PCM), and others).

[0126] The controller 602 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 600 to cause the processor 600 to support various operations in accordance with examples as described herein. For example, the controller 602 may operate as a control unit of the processor 600, generating control signals that manage the operation of various components of the processor 600. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

[0127] The controller 602 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 604 and determine subsequent instruction(s) to be executed to cause the processor 600 to support various operations in accordance with examples as described herein. The controller 602 may be configured to track memory address of instructions associated with the memory 604. The controller 602 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 602 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 600 to cause the processor 600 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 602 may be configured to manage flow of data within the processor 600. The controller 602 may be configured to control transfer Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 35 of data between registers, arithmetic logic units (ALUs), and other functional units of the processor 600.

[0128] The memory 604 may include one or more caches (e.g., memory local to or included in the processor 600 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 604 may reside within or on a processor chipset (e.g., local to the processor 600). In some other implementations, the memory 604 may reside external to the processor chipset (e.g., remote to the processor 600).

[0129] The memory 604 may store computer-readable, computer-executable code including instructions that, when executed by the processor 600, cause the processor 600 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 602 and / or the processor 600 may be configured to execute computer-readable instructions stored in the memory 604 to cause the processor 600 to perform various functions. For example, the processor 600 and / or the controller 602 may be coupled with or to the memory 604, the processor 600, the controller 602, and the memory 604 may be configured to perform various functions described herein. In some examples, the processor 600 may include multiple processors and the memory 604 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

[0130] The one or more ALUs 606 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 606 may reside within or on a processor chipset (e.g., the processor 600). In some other implementations, the one or more ALUs 606 may reside external to the processor chipset (e.g., the processor 600). One or more ALUs 606 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 606 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 606 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 36 gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 606 may support logical operations such as AND, OR, exclusive-OR (XOR), not-OR (NOR), and not-AND (NAND), enabling the one or more ALUs 606 to handle conditional operations, comparisons, and bitwise operations. The processor 600 may support wireless communication in accordance with examples as disclosed herein. The processor 600 may be configured to or operable to support a means for receiving a configuration message for a beam management procedure, receiving first reference signals over a first set of reference signal resources in wide beam transmissions from a plurality of transmission-reception points (TRPs), determining at least one candidate narrow beam of each TRP of a set of TRPs of the plurality of TRPs, and transmitting a first indication indicating the at least one candidate narrow beam of each TRP of the set of TRPs to a network entity.

[0131] Figure 7 illustrates an example of a NE 700 in accordance with aspects of the present disclosure. The NE 700 may include a processor 702, a memory 704, a controller 706, and a transceiver 708. The processor 702, the memory 704, the controller 706, or the transceiver 708, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

[0132] The processor 702, the memory 704, the controller 706, or the transceiver 708, or various combinations or components thereof may be implemented in hardware (e.g., circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

[0133] The processor 702 may include an intelligent hardware device (e.g., a general- purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof). In some implementations, the processor 702 may be configured to operate the memory 704. In some other implementations, the memory 704 may be integrated into the processor 702. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 37 The processor 702 may be configured to execute computer-readable instructions stored in the memory 704 to cause the NE 700 to perform various functions of the present disclosure.

[0134] The memory 704 may include volatile or non-volatile memory. The memory 704 may store computer-readable, computer-executable code including instructions when executed by the processor 702 cause the NE 700 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such the memory 704 or another type of memory. Computer-readable media includes both non- transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

[0135] In some implementations, the processor 702 and the memory 704 coupled with the processor 702 may be configured to cause the NE 700 to perform one or more of the functions described herein (e.g., executing, by the processor 702, instructions stored in the memory 704). For example, the processor 702 may support wireless communication at the NE 700 in accordance with examples as disclosed herein. The NE 700 may be configured to support a means for receiving a configuration message for a beam management procedure, receiving first reference signals over a first set of reference signal resources in wide beam transmissions from a plurality of transmission-reception points (TRPs), determining at least one candidate narrow beam of each TRP of a set of TRPs of the plurality of TRPs, and transmitting a first indication indicating the at least one candidate narrow beam of each TRP of the set of TRPs to a network entity.

[0136] The controller 706 may manage input and output signals for the NE 700. The controller 706 may also manage peripherals not integrated into the NE 700. In some implementations, the controller 706 may utilize an operating system such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some implementations, the controller 706 may be implemented as part of the processor 702.

[0137] In some implementations, the NE 700 may include at least one transceiver 708. In some other implementations, the NE 700 may have more than one transceiver 708. The Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 38 transceiver 708 may represent a wireless transceiver. The transceiver 708 may include one or more receiver chains 710, one or more transmitter chains 712, or a combination thereof.

[0138] A receiver chain 710 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 710 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 710 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. The receiver chain 710 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 710 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

[0139] A transmitter chain 712 may be configured to generate and transmit signals (e.g., control information, data, packets). The transmitter chain 712 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM). The transmitter chain 712 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 712 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0140] Figure 8 illustrates a flowchart of a method in accordance with aspects of the present disclosure. The operations of the method may be implemented by a UE as described herein. In some implementations, the UE may execute a set of instructions to control the function elements of the UE to perform the described functions.

[0141] At 802, the method may include receiving a configuration message for a beam management procedure. The operations of 802 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 802 may be performed by a UE as described with reference to Figure 5. The configuration message may be, for example, a CSI configuration setting. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 39

[0142] At 804, the method may include receiving, from a set of TRPs, a first set of reference signals via a set of wide beams and during the beam management procedure, wherein the first set of reference signals is associated with a first set of reference signal resources, and wherein each beam of the set of wide beams is associated with a corresponding beam identifier. The operations of 804 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 804 may be performed by a UE as described with reference to Figure 5.

[0143] At 806, the method may include selecting at least one candidate narrow beam based at least in part on the first set of reference signals received via the set of wide beams. The operations of 806 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 806 may be performed a UE as described with reference to Figure 5.

[0144] At 808, the method may include transmitting a report that indicates the at least one candidate narrow beam to a network entity. The operations of 808 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 808 may be performed a UE as described with reference to Figure 5.

[0145] It should be noted that the method described herein describes a possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0146] The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein. Attorney Docket No.793MS0154PC

Claims

Lenovo Docket No. SMM920240015-WO-PCT 40 CLAIMS What is claimed is:

1. A user equipment (UE) for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: receive a configuration message for a beam management procedure; receive, from a set of transmission-reception points (TRPs), a first set of reference signals via a set of wide beams and during the beam management procedure, wherein the first set of reference signals is associated with a first set of reference signal resources, and wherein each beam of the set of wide beams is associated with a corresponding beam identifier; select at least one candidate narrow beam based at least in part on the first set of reference signals received via the set of wide beams; and transmit a report that indicates the at least one candidate narrow beam to a network entity.

2. The UE of claim 1, wherein the first indication separately indicates the at least one candidate narrow beam of each TRP of the set of TRPs.

3. The UE of claim 2, wherein the report indicates at least one of a received power and a signal-to-interference-and-noise-ratio (SINR) associated with each candidate narrow beam.

4. The UE of claim 1, wherein the report indicates a plurality of beam groups, each beam group comprising candidate narrow beams associated with respective TRPs of the set of TRPs.

5. The UE of claim 1, wherein the configuration message indicates a first UE codebook for wide beam transmissions and a second UE codebook for narrow beam transmissions. Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 41 6. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to: receive a second set of reference signals from a set of narrow beam groups comprising narrow beams from the set of TRPs; measure power values of the set of narrow beams groups; and transmit a second indication to the network entity indicating at least a narrow beam group of the set of narrow beam groups with a highest power value.

7. The UE of claim 6, wherein the second indication indicates a plurality of narrow beam groups.

8. The UE of claim 6, wherein the second indication is provided in a channel state information (CSI) report comprising at least one of a resource indicator associated with at least one of the narrow beam groups, received power of the second reference signals and received SINR of the second reference signals.

9. The UE of claim 6, wherein the second reference signals are associated with one or more of: a set of non-zero power CSI resources, a set of resources configured with a joint transmission parameter, and a set of demodulation reference signals (DMRSs).

10. The UE of claim 1, wherein the first set of reference signals are associated with one or more of: a synchronization signal (SS) block, a tracking reference signal (TRS), and a first set of non-zero power CSI resources.

11. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to: receive a third set of reference signals from a single narrow beam group including one or more narrow beam each associated with a TRP of a second set of TRPs; and Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 42 select a receive beam for communicating with the second set of TRPs from a plurality of receive beams.

12. The UE of claim 11, wherein the plurality of receive beams include at least one narrow receive beam and at least one wide receive beam.

13. A processor for wireless communication, comprising: at least one controller coupled with at least one memory and configured to cause the processor to: receive a configuration message for a beam management procedure; receive, from a set of transmission-reception points (TRPs), a first set of reference signals via a set of wide beams and during the beam management procedure, wherein the first set of reference signals is associated with a first set of reference signal resources, and wherein each beam of the set of wide beams is associated with a corresponding beam identifier; select at least one candidate narrow beam based at least in part on the first set of reference signals received via the set of wide beams; and transmit a report that indicates the at least one candidate narrow beam to a network entity.

14. The processor of claim 13, wherein the first indication separately indicates the at least one candidate narrow beam of each TRP of the set of TRPs.

15. A method performed by a user equipment (UE), the method comprising: receiving a configuration message for a beam management procedure; receiving, from a set of transmission-reception points (TRPs), a first set of reference signals via a set of wide beams and during the beam management procedure, wherein the first set of reference signals is associated with a first set of reference signal resources, and wherein each beam of the set of wide beams is associated with a corresponding beam identifier; selecting at least one candidate narrow beam based at least in part on the first set of reference signals received via the set of wide beams; and Attorney Docket No.793MS0154PCLenovo Docket No. SMM920240015-WO-PCT 43 transmitting a report that indicates the at least one candidate narrow beam to a network entity 16. The method of claim 15, further comprising: receiving a second set of reference signals from a set of narrow beam groups comprising narrow beams from the set of TRPs; measuring power values of the set of narrow beams groups; and transmitting a second indication to the network entity indicating at least a narrow beam group of the set of narrow beam groups with a highest power value.

17. The method of claim 16, wherein the report indicates at least one of a received power and a signal-to-interference-and-noise-ratio (SINR) associated with each candidate narrow beam.

18. The method of claim 15, wherein the report indicates a plurality of beam groups, each beam group comprising candidate narrow beams associated with respective TRPs of the set of TRPs.

19. The method of claim 15, wherein the configuration message indicates a first UE codebook for wide beam transmissions and a second UE codebook for narrow beam transmissions.

20. The method of claim 15, further comprising: receiving a second set of reference signals from a set of narrow beam groups comprising narrow beams from the set of TRPs; measuring power values of the set of narrow beams groups; and transmitting a second indication to the network entity indicating at least a narrow beam group of the set of narrow beam groups with a highest power value. Attorney Docket No.793MS0154PC

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