Multi-trp beam management via beam group reporting

Abstract

Various aspects of the present disclosure relate to a user equipment (UE) for wireless communication having 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) via a set of wide beams, a set of first reference signals during the beam management procedure, wherein the set of first reference signals is associated with a set of first 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 set of first reference signals received via the set of wide beams, and transmit, to a network entity, a report indicating the at least one candidate narrow beam.

Description

Cross-citation of related applications

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

[0002] This disclosure relates to wireless communications, and more specifically, to beam management in multi-TRP environments. Background Technology

[0003] A wireless communication system may include one or more network communication devices, such as base stations, which can support wireless communication with one or more user communication devices, which may also be referred to as user equipment (UE) or other suitable terms. The wireless communication system can support wireless communication with one or more user communication devices by utilizing the resources of the wireless communication system (e.g., time resources (e.g., symbols, time slots, subframes, frames, etc.) or frequency resources (e.g., subcarriers, carriers, etc.)). Furthermore, the wireless communication system can support wireless communication across various radio access technologies, including third-generation (3G), fourth-generation (4G), fifth-generation (5G), and other suitable radio access technologies beyond 5G (e.g., sixth-generation (6G)). Summary of the Invention

[0004] The article “a” preceding an element is not limited and should be understood to refer to “at least one” or “one or more” of those elements. The terms “a,” “at least one,” “one or more,” and “at least one of one or more” are interchangeable. As used herein, including as used in the claims, the word “or” used in a list of items (e.g., a list of items preceding phrases such as “at least one of,” “one or more of,” or “one or both of”) indicates an inclusive list, such that a list of at least one of, for example, A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase “based on” should not be understood to refer to a closed set of conditions. For example, without departing from the scope of this disclosure, an exemplary step described as “based on condition A” may be based on both condition A and condition B. In other words, as used herein, the phrase “based on” should also be interpreted as the phrase “at least partially based on.” Furthermore, as used herein, including as used in the claims, a “set” may contain one or more elements.

[0005] A UE, processor, and method for wireless communication are described. The UE may be configured, enabled, or operable to perform one or more operations as described herein. For example, the UE may be configured, enabled, or operable to receive configuration messages for a beam management procedure; during the beam management procedure, receive a first set of reference signals from a set of transmit-receive points (TRPs) via a wide beam set, wherein the first set of reference signals is associated with a first set of reference signal resources, and wherein each beam in the wide beam set 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 wide beam set; and transmit a report indicating the at least one candidate narrow beam to a network entity.

[0006] In some embodiments of the UE, processor, and method described herein, the first indication individually indicates the at least one candidate narrow beam for each TRP in the TRP set.

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

[0008] In some implementations of the UE, processor, and methods described herein, the report indicates multiple beam groups, each beam group including candidate narrow beams associated with a corresponding TRP in the TRP set.

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

[0010] In some embodiments of the UE, processor, and method described herein, the UE is operable to receive a second reference signal set from a narrow beam set, the narrow beam set including narrow beams from the TRP set; measure the power value of the narrow beam set; and transmit a second indication to the network entity, the second indication indicating at least one narrow beam set in the narrow beam set having the highest power value.

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

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

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

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

[0015] In some embodiments of the UE, processor, and method described herein, the UE is operable to receive a third reference signal set from a single narrow beam group, the single narrow beam group comprising one or more narrow beams each associated with a TRP in the second TRP set, and a receive beam selected from a plurality of receive beams for communicating with the second TRP set.

[0016] In some embodiments of the UE, processor, and method described herein, the plurality of receive beams include at least one narrow receive beam and at least one wide receive beam. Attached Figure Description

[0017] Figure 1 Examples of wireless communication systems according to various aspects of this disclosure are shown.

[0018] Figure 2 Examples of wireless communication systems supporting beam management according to various aspects of this disclosure are shown.

[0019] Figure 3 An example is shown of a UE receiving a narrow beam group from a TRP according to various aspects of this disclosure.

[0020] Figure 4 An example of selecting a receiving beam for communication with TRP according to various aspects of this disclosure is shown.

[0021] Figure 5 An example of a user equipment (UE) 500 according to various aspects of this disclosure is shown.

[0022] Figure 6 An example of a processor 600 according to various aspects of this disclosure is shown.

[0023] Figure 7 Examples of network equipment (NE) 700 according to various aspects of this disclosure are shown.

[0024] Figure 8 A flowchart illustrating a method performed by a UE according to various aspects of this disclosure is shown. Detailed Implementation

[0025] Beamforming is a technique in which a transmitting antenna array concentrates transmitted power in a specific spatial direction by adjusting the phase and amplitude of symbols transmitted from its antenna elements. In this way, the transmitter delivers maximum power to a target device in a specific direction while minimizing interference to other devices. If the target device has multiple antennas, it can perform beamforming by combining the signals received at its antennas with phase and amplitude adjusted coefficients, thereby maximizing received power in a specific spatial direction. These two types of beamforming are referred to as transmit beamforming and receive beamforming, respectively. Transmit beamforming may involve transmitting one or more beams in a certain direction, while receive beamforming may involve tuning a receiver to a certain direction.

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

[0027] The use of each beamforming type and its hybrid types depends on the characteristics and requirements of the communication scenario. In lower frequency bands where bandwidth is scarcer and fewer antennas are used at the transmit / receive arrays, digital beamforming offers higher spectral efficiency through spatial multiplexing and is therefore preferred. In higher frequency bands where bandwidth is abundant and more transmit / receive antennas are used (due to shorter wavelengths and denser antenna arrangements), analog beamforming is less costly and is generally preferred. In most scenarios, the optimal trade-off between spatial resolution and cost / complexity is achieved by using hybrid beamforming.

[0028] When communicating using analog beams, it is important for both the transmitter and receiver to agree on a pair of transmit / receive beams. With this pair, the channel achieves higher aggregated power and is therefore suitable for communication. The process of acquiring this beam pair and recovering it in case of loss is called beam management (BM). In 5G NR, the beam pair acquisition portion of BM is generally performed by: "scanning" multiple beam pairs, measuring the received power of each beam pair according to L1-RSRP, and reporting the optimal beam pair and its received power from the receiver to the transmitter.

[0029] A new feature of enhanced massive MIMO in 5G NR is multiple transmit and receive points (multiple TRPs), where the gNB uses more than one antenna array located at generally different locations to transmit to the user equipment (UE). TRPs can cooperate coherently by transmitting the same data to the UE via coherent joint transmission (CJT) or by transmitting different data (i.e., different layers) to the UE via incoherent joint transmission (NCJT). Multiple TRPs provide higher channel diversity, better interference management, and more uniform channel quality for UEs at both the cell center and cell edge in both ways.

[0030] For multiple TRPs, downlink beamforming (BM) is equivalent to finding a set of transmit and receive beams that enable a high-quality aggregation channel for the transmit and receive beams. Traditional BM frameworks are designed for single transmitters and receivers and cannot be directly applied to multiple TRPs. This is because measuring power by continuously scanning the beams for each TRP is very time-consuming. For example, if M TRPs can each form N analog beams, and the UE can form K analog beams, then the UE must measure M × N × K received L1-RSRPs, each L1-RSRP corresponding to a beam pair. This can be a large number, especially when many TRPs are involved (M... 1).

[0031] The solution to the downlink beamforming problem in multi-TRP (Transmitter-Related Platform) scenarios consists of extending the traditional P-1, P-2, P-3 procedures to multiple transmitters. In this scenario, an initial beam pair is first established between the UE and each of the TRPs. Then, by determining the beam pairs, the network identifies multiple beam groups containing modified / adjusted beams, each beam group corresponding to a different TRP. Finally, the UE measures the L1-RSRP of each of these beam groups and reports the number of beam groups with the highest L1-RSRP to the network.

[0032] More specifically, a beam pair consists of the processes of establishing, maintaining, and restoring a pair of beams between a transmitter and a receiver, which together provide a high-quality channel. In the downlink, the transmitter is a gNB and the receiver is a UE; and in the uplink, the transmitter is a UE and the receiver is a gNB. The beam pair established in the downlink may or may not be available for the uplink based on the property known as beam correspondence between the downlink and uplink channels. Although the discussion in this disclosure is primarily from the perspective of a downlink beam pair, embodiments are not limited to downlink beam pairs and can be extended to uplink beam pairs.

[0033] A typical downlink BM consists of three procedures (referred to as P-1, P-2, and P-3).

[0034] In P-1, the UE establishes an initial beam pair with the gNB by exchanging the Initial Access Synchronization (SS) signal and the Random Access Channel (RACH) preamble. The gNB transmits an "SS burst" consisting of several SS blocks, each associated with a different transmit beam. The UE receives the SS bursts sequentially with its receive beam, measures the L1-RSRP of each beam pair, and reports the index of the "optimal" transmit beam to the gNB by sending the RACH preamble at the RACH timing associated with the SS block carried by that beam. When the UE is still in idle mode, the SS block beams are typically wider to cover a larger angular span, and therefore the initially acquired beam pair consists of wide beams.

[0035] In P-2, the gNB improves the transmit beam by transmitting a set of Channel State Information Reference Signals (CSI-RS) carried in a narrower beam. These beams are selected to cover the same angular span as the wide transmit beam selected in P-1, thereby attempting to improve the spatial focusing of the transmit beam. Simultaneously, the UE measures the transmitted CSI-RS with a fixed receive beam. The UE then reports the indices of up to four of the strongest improved beams and the L1-RSRP to the gNB.

[0036] In P-3, the gNB fixes the transmit beam and CSI-RS to the UE, while the UE scans its receive beam and measures the L1-RSRP. The UE selects the optimal receive beam based on these measurements.

[0037] One problem with this approach is that in a multi-TRP environment, there are too many candidate beamsets that the network must transmit at P-2. This is because there may be a large number of TRPs, and each TRP may have a large number of candidate modified / adjusted beamsets for transmission. A large number of candidate beamsets leads to significant overhead in measurements and reporting.

[0038] Embodiments of this disclosure relate to a low-complexity beamforming method for multiple TRPs. Some implementations include two analog beamcodebooks at both the TRP and the UE, one consisting of “wide” beams and the other consisting of “narrow” beams. The wide beams have lower spatial resolution and cover a larger spatial aperture; while the narrow beams have higher spatial resolution and cover a smaller spatial aperture. Although the two codebooks may cover the same spatial span, the number of wide beams is less than the number of narrow beams.

[0039] BM can be performed in three phases. In the first phase, each TRP sends a reference signal (RS) to the UE by scanning its wide transmit beams. The UE uses each of its wider receive combined beams to receive the RS transmitted by each wide beam. The UE uses these measurements to determine the narrow transmit beam set, which it then reports to the network.

[0040] In the second phase, for the beam set corresponding to the beam set reported by the UE, the network jointly transmits RS via the narrow beams contained in the beam set. The UE measures the L1-RSRP of the signal received for each beam set and reports an indication to the network of the number of beam sets with the highest L1-RSRP.

[0041] In the third phase, the network selects a beam group and transmits RS through multiple symbols, while the UE scans its narrow receive combination beam and selects the beam with the highest receive power.

[0042] As part of the first phase, the UE can identify candidate narrow transmit beam groups from measurements on wide transmit / receive beams by leveraging channel sparsity. This reduces overhead because the number of wide beams at the transmitter and receiver may be much smaller than the number of narrow beams. Reporting candidate narrow transmit beam groups from the UE to the network also proposes an efficient solution for BM in multi-TRP systems, where the number of candidate transmit beam groups is typically so high that it is impossible to scan all of them and select the optimal group.

[0043] Embodiments of this disclosure reduce overhead associated with BM by reporting candidate beam sets from the UE to the network in a first phase, which substantially limits the beam sets to be measured and reported, and thus reduces overhead.

[0044] Various aspects of this disclosure are described in the context of wireless communication systems.

[0045] Figure 1 Examples of a wireless communication system 100 according to various aspects of this disclosure are shown. The wireless communication system 100 may include one or more NEs 102, one or more UEs 104, and a core network (CN) 106. The wireless communication system 100 may support various radio access technologies. In some embodiments, the wireless communication system 100 may be a 4G network, such as an LTE network or an LTE-A enhanced network. In some other embodiments, the wireless communication system 100 may be an NR network, such as a 5G network, a 5G-A enhanced network, or a 5G ultra-wideband (5G-UWB) network. In other embodiments, the wireless communication system 100 may be a combination of 4G and 5G networks, or other suitable radio access technologies, including IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), and IEEE 802.20. The wireless communication system 100 may support radio access technologies beyond 5G (e.g., 6G). In addition, the wireless communication system 100 may support technologies such as Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), or Code Division Multiple Access (CDMA).

[0046] One or more NEs 102 may be distributed throughout a geographic area to form a wireless communication system 100. One or more of the NEs 102 described herein may be, include, or be referred to as a network node, base station, network element, network function, network entity, radio access network (RAN), NodeB, eNodeB (eNB), next-generation NodeB (gNB), or other suitable terms. NEs 102 and UEs 104 may communicate via a communication link, which may be a wireless or wired connection. For example, NEs 102 and UEs 104 may perform wireless communication (e.g., receiving signaling, transmitting signaling) via a Uu interface.

[0047] NE 102 can provide a geographic coverage area within which it can support the services of one or more UEs 104. For example, NE 102 and UE 104 can support wireless communication of signals associated with services (e.g., voice, video, packet data, messaging, broadcasting, etc.) based on one or more radio access technologies. In some embodiments, NE 102 can be mobile, such as a satellite associated with a non-terrestrial network (NTN). In some embodiments, different geographic coverage areas 112 associated with the same or different radio access technologies can overlap, but different geographic coverage areas can be associated with different NEs 102.

[0048] One or more UEs 104 may be distributed throughout the geographic area of ​​the wireless communication system 100. UE 104 may include or be referred to as a remote unit, mobile device, wireless device, remote device, subscriber device, transmitter device, receiver device, or any other suitable term. In some embodiments, UE 104 may be referred to as a unit, station, terminal, or client, among other examples. Additionally, or alternatively, UE 104 may be referred to as an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a Machine Type Communication (MTC) device, among other examples.

[0049] UE 104 may be able to support direct wireless communication with other UE 104 via a communication link. For example, UE 104 may support direct wireless communication with another UE 104 via 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, UE 104 may support direct wireless communication with another UE 104 via a PC5 interface.

[0050] NE 102 may support communication with CN 106, communication with another NE 102, or both. For example, NE 102 may connect to other NE 102 or CN 106 interfaces via one or more backhaul links (e.g., S1, N2, N2, or network interfaces). In some embodiments, NE 102 may communicate directly with each other. In some other embodiments, NE 102 may communicate with each other, or indirectly (e.g., via CN 106). In some embodiments, one or more NE 102 may include sub-components, such as access network entities, which may be an example of an Access Node Controller (ANC). The ANC may communicate with one or more UE 104s via one or more other access network transmitting entities, which may be referred to as a radio headend, smart radio headend, or transmit-receive point (TRP).

[0051] CN 106 can support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. CN 106 can be an evolved packet core (EPC) or a 5G core (5GC), and may include control plane entities that manage access and mobility (e.g., Mobility Management Entity (MME), Access and Mobility Management Function (AMF)), and user plane entities that route packets or interconnect with external networks (e.g., Serving Gateway (S-GW), Packet Data Network (PDN) Gateway (P-GW), or User Plane Function (UPF)). In some implementations, the control plane entities can manage non-access stratum (NAS) functions of one or more UEs 104 served by one or more NEs 102 associated with CN 106, such as mobility, authentication, and bearer management (e.g., data bearers, signaling bearers, etc.).

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

[0053] In the wireless communication system 100, NE 102 and UE 104 can use the resources of the wireless communication system 100 (e.g., time resources (e.g., symbols, time slots, subframes, frames, etc.) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communication). In some embodiments, NE 102 and UE 104 may support different resource structures. For example, NE 102 and UE 104 may support different frame structures. In some embodiments, such as in 4G, NE 102 and UE 104 may support a single frame structure. In some other embodiments, such as in 5G and other suitable radio access technologies, NE 102 and UE 104 may support various frame structures (i.e., multiple frame structures). NE 102 and UE 104 may support various frame structures based on one or more parameter sets.

[0054] One or more parameter sets can be supported in the wireless communication system 100, and the parameter sets may include subcarrier spacing and cyclic prefix. The first parameter set (e.g., This can be associated with a first subcarrier spacing (e.g., 15 kHz) and a conventional cyclic prefix. In some implementations, a first set of parameters (e.g., ...) associated with the first subcarrier spacing (e.g., 15 kHz) is... One time slot can be used per subframe. The second parameter set (e.g., This can be associated with the second subcarrier spacing (e.g., 30 kHz) and the regular cyclic prefix. The third parameter set (e.g., This can be associated with the third subcarrier spacing (e.g., 60 kHz) and the regular cyclic prefix or extended cyclic prefix. The fourth parameter set (e.g., This can be associated with the fourth subcarrier spacing (e.g., 120 kHz) and the regular cyclic prefix. The fifth parameter set (e.g., This can be associated with the fifth subcarrier spacing (e.g., 240 kHz) and the regular cyclic prefix.

[0055] Time intervals for resources (e.g., communication resources) can be organized according to frames (also known as radio frames). Each frame may have a duration, such as 10 milliseconds (ms). In some embodiments, each frame may contain multiple subframes. For example, each frame may contain 10 subframes, and each subframe may have a duration, such as 1 ms. In some embodiments, each frame may have the same duration. In some embodiments, each subframe of a frame may have the same duration.

[0056] Alternatively, the time intervals of resources (e.g., communication resources) can be organized according to time slots. For example, a subframe may contain a certain number (e.g., quantity) of time slots. The number of time slots in each subframe may also depend on one or more sets of parameters supported in the wireless communication system 100. For example, the first, second, third, fourth, and fifth sets of parameters (i.e., ...) associated with the corresponding subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz. , , , , The subframe can utilize a single time slot per subframe, two time slots per subframe, four time slots per subframe, eight time slots per subframe, and 16 time slots per subframe, respectively. Each time slot can contain a certain number (e.g., quantity) of symbols (e.g., OFDM symbols). In some implementations, the number (e.g., quantity) of time slots in a subframe can depend on the parameter set. For a regular cyclic prefix, a time slot can contain 14 symbols. For an extended cyclic prefix (e.g., for a 60 kHz subcarrier spacing), a time slot can contain 12 symbols. The relationship between the number of symbols per time slot, the number of time slots per subframe, and the number of time slots per frame for the regular and extended cyclic prefixes can depend on the parameter set. It should be understood that for a first parameter set (e.g., quantity) associated with a first subcarrier spacing (e.g., 15 kHz), The references to ) can be used interchangeably between subframes and time slots.

[0057] In the wireless communication system 100, the electromagnetic (EM) spectrum can be divided into various categories, frequency bands, channels, etc., based on frequency or wavelength. For example, the wireless communication system 100 may support one or more operating frequency bands, such as frequency range identifiers FR1 (410 MHz to 7.125 GHz), FR2 (24.25 GHz to 52.6 GHz), FR3 (7.125 GHz to 24.25 GHz), FR4 (52.6 GHz to 114.25 GHz), FR4a or FR4-1 (52.6 GHz to 71 GHz), and FR5 (114.25 GHz to 300 GHz). In some embodiments, NE 102 and UE 104 may perform wireless communication on one or more of the operating frequency bands. In some embodiments, FR1 may be used by NE 102 and UE 104, as well as other equipment or devices for cellular communication traffic (e.g., control information, data). In some implementations, FR2 may be used by NE 102 and UE 104, as well as other equipment or devices for short-range high data rate capability.

[0058] FR1 can be associated with one or more parameter sets (e.g., at least three parameter sets). For example, FR1 can be associated with the following: the first parameter set (e.g., ), which includes a 15 kHz subcarrier spacing; the second parameter set (e.g., ), which includes a 30 kHz subcarrier spacing; and a third parameter set (e.g., ), which includes a 60 kHz subcarrier spacing. FR2 can be associated with one or more parameter sets (e.g., at least two parameter sets). For example, FR2 can be associated with the following: a third parameter set (e.g., ), which includes a 60 kHz subcarrier spacing; and a fourth parameter set (e.g., It contains a 120 kHz subcarrier spacing.

[0059] Multiple TRP operation refers to using multiple TRPs to transmit or receive data in a network. These multiple TRPs are geographically separated and may correspond to current cell sites or access points in a distributed or cellular-less antenna system. The advantages of multiple TRPs include: increased channel power due to coherent beamforming among several transmitters (or receivers); improved channel robustness against obstruction and fading due to spatial diversity; and enhanced spatial multiplexing by transmitting different data layers from different transmitters.

[0060] In NR, multi-TRP operation in the downlink consists of two main schemes. The first scheme is (a) transmitting different data from multiple TRPs, which is called noncoherent joint transmission (NCJT). This results in increased UE data rates due to spatial multiplexing and is beneficial for enhanced mobile broadband (eMBB) applications. In terms of scheduling, data can be transmitted 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 suitable for lower frequency bands, firstly because it is difficult for UEs to receive data simultaneously from different directions in higher frequency bands, and secondly because the spectral efficiency gain provided by NCJT is more helpful in lower frequency bands than in higher frequency bands. However, there are no limitations on using NCJT in higher frequency bands.

[0061] The second approach (b) involves transmitting the same data from multiple TRPs to enhance channel reliability and beamforming gain. First, the same data can be transmitted at different times (time division multiplexing) or at different frequencies (frequency division multiplexing). This repetitive data transmission allows data to be received from a second TRP even if the channel of one TRP is severely blocked or fading. This provides the benefits of Ultra-Reliable Low-Latency Communication (URLLC). Alternatively, the same data can be transmitted at the same resource concentration by multiple TRPs with close time and frequency synchronization; this is known as Coherent Joint Transmission (CJT). CJT improves received power and beamforming gain, which is particularly suitable for higher frequency bands with power constraints.

[0062] Embodiments of this disclosure provide a solution for determining a set of transmit beams (each transmit beam is transmitted by the TRP) and receive beams at the UE, resulting in a high-quality combined channel between the TRP and the UE. The beams can be determined by beam steering vectors composed of phase and amplitude coefficients, with each array antenna port transmitting or receiving signals using these phase and amplitude coefficients. If the array has… If the port is selected, the beam steering vector can be a vector. Consider the following scenario: carrying symbols The signal is received at the angle of arrival (AoA). Incident on the array, and the array combines the signal with a vector Combination. In the absence of noise, the received signal is composed of... Given, among which Indicates symbolic power, and For AoA The array response vector is given below. For simplicity, assume... and The received power as an AoA function is determined by... Given. The same expression applies to having The transmit power of an array of antenna ports.

[0063] The purpose of beamforming is to concentrate received / transmitted power within a region around a specific AoA or AoD angle. As an example, beamforming can be based on the Discrete Fourier Transform (DFT) vector associated with a uniformly spaced AoA / AoD grid. Half-power beamwidth (HPBW) is defined as the order of magnitude of the radiation pattern (denoted here as...). The angular span from the peak value of the main beam down by 3dB.

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

[0065] The following discussion and... The discussion relates to the downlink BM of a network consisting of individual TRPs and individual UEs. For ease of explanation, the following discussion assumes that each TRP is equipped with the same number of... Dual-polarized antenna, and the UE is equipped with Dual-polarized antenna. In this embodiment, both the UE and the TRP have two sets of beam steering vector codebooks.

[0066] Each TRP can use a codebook representing a wide transmit beam, represented as follows: , and another codebook representing a narrow transmit beam, denoted as ,in It is a TRP index, and and These represent the number of wide transmit beams and narrow transmit beams, respectively. In some embodiments, the wide transmit beam codebook and the narrow transmit beam codebook may be identical on the TRP, such that for all , and The dimension of each element in the codebook can be equal to the number of transmit antenna ports at the TRP, that is, for all... , , , .

[0067] The UE can use a codebook representing a wide receive beam, represented as follows: And another codebook representing a narrow receive beam, denoted as ,in and These represent the number of wide and narrow receive beams, respectively. The dimension of each element in the codebook is equal to the number of receive antenna ports at the UE, i.e., for all... , , .

[0068] As an example, wide beams can correspond to beams used for transmitting or receiving synchronization signal blocks (SSBs) from the TRP to the UE in idle mode. Compared to narrow beams, these beams can cover a larger angular span and are fewer in number. On the other hand, narrow beams can correspond to improved beams used for transmitting / receiving CSI-RS from the 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, there are more narrow beams than wide beams. and Furthermore, without loss of generality, the above discussion assumes that all vectors have a unit norm, such that for all... , , , .

[0069] The transmit and receive beamcodebooks can be obtained at the UE, but in some embodiments, the network may not be able to access the receive beamcodebook. and The transmit beam codebook can be indicated explicitly or implicitly in configuration messages from the network to the UE. For example, the network can transmit parameters to the UE, and the codebook can be uniquely identified using these parameters. The configuration message can be, for example, CSI configuration settings. Alternatively, the codebook or its parameters can be pre-configured at the UE.

[0070] In some embodiments, the UE may use one codebook instead of two codebooks, which means For example, a UE may use only a wide beam because in downlink multi-TRP, the UE may need to be able to receive signals from multiple directions simultaneously, and the UE's orientation may change rapidly in mobility situations. On the other hand, it may be beneficial to transmit with both narrow and wide beams at the TRP, because the wide beam can quickly establish an initial beam pair with the UE, while the narrow beam concentrates power in one direction and causes less interference to other UEs.

[0071] As an example, wide beam and narrow beam designs can be implemented as follows. In the example, the following is provided: Each dimension is The beam vector, where The number can be either wide beams or narrow beams, and among them Can be equal to the number of transmitting antenna ports Or the number of receiving antenna ports As an example, this can be achieved using what is known as "balanced beaming." This represents the angular aperture of a transmitting or receiving antenna array, encompassing all spatial directions from which the array can transmit power. For planar arrays, It is a 2D azimuth-zenith angle value set. The above definition has A uniform grid of points is represented as... Then Defined as with A vector of the same dimension. This vector indicates the beamwidth parameter in each angular direction (e.g., azimuth and zenith angle). To obtain the beam vector, solve the following optimization problem:

[0072]

[0073] The constraints are .

[0074] in It is a dimension of Optimization variable vector, express The element, yes The element, for The element and For angle The dimension is The array response vector. This problem can be solved by finding the eigenvector corresponding to the largest eigenvalue of the positive semi-definite matrix:

[0075] .

[0076] After solving this problem, the first Beam (its dimension is) The beamwidth is given by the vector. Control. For example, the widths of wide and narrow beams can have the following relationship: ,in It is a scalar greater than 1. The number of beams can be determined by variables. To set, and the direction of the beam can be determined by setting grid points. To control. However, this is just one example of how wide and narrow beams can be designed, and networks and UEs can use other examples for wide and narrow beams.

[0077] An embodiment of the BM method for multiple TRPs can be described in terms of three phases. In phase 1, each TRP can transmit a "burst" of a reference signal "block," where each block uses data from the set... Different wide beams are emitted. Therefore, the burst at least includes Each block spans a certain number of symbols and subcarriers. For example, the reference signal could be SS, where each SS block spans four OFDM symbols and 240 subcarriers, and the SS burst sets can be in FR1 ( FR1 The FR2 (millimeter wave) and FR2 (millimeter wave) contain 4, 8, and 64 SS blocks, respectively. The UE can access these blocks through its application. Each RS block is received by receiving each of the wide beams. Digital beamforming allows multiple receive beams to be applied simultaneously, while analog beamforming allows the UE to scan its receive beams and apply each receive beam to different receive symbols.

[0078] Figure 2Examples of wireless communication systems supporting beam management according to various aspects of this disclosure are shown. For example, the wireless communication system may support beamforming communication between one or more of TRP 102a, TRP 102b, and UE 104, each of which may be referenced herein. Figure 1 The described example corresponds to a UE or NE. TRP 102a can transmit one or more sets of reference signals through one or more sets of wide beams (also referred to herein as wide transmit beams). Figure 2 In the example, the TRP102a can transmit a reference signal on each of the four wide transmit beams (in Figure 2 This is also represented as RS. For example, TRP 102a can transmit RS-1 via wide transmit beam 301, RS-2 via wide transmit beam 302, RS-3 via wide transmit beam 303, and RS-4 via wide transmit beam 304. Alternatively, TRP 102b can transmit one or more sets of reference signals via one or more sets of wide beams. Figure 2 In the example, TRP 102b can transmit a reference signal on each of the four wide transmit beams. For example, TRP 102b can transmit RS-5 via wide transmit beam 305, RS-6 via wide transmit beam 306, RS-7 via wide transmit beam 307, and RS-8 via wide transmit beam 308. In some cases, beamforming communication performed by one or more of TRP 102a or TRP 102b can be in the analog domain, in which case the beamforming communication is performed sequentially (e.g., time-wise). Sequential beamforming communication in Figure 2 It is shown in dashed lines.

[0079] UE 104 can receive one or more sets of reference signals through one or more sets of wide beams (also referred to herein as wide receive beams). Figure 2In the example, UE 104 can receive a reference signal on each of the three wide receive beams. For example, UE 104 can receive a corresponding reference signal from one or both of TRP 102a or TRP 102b via each of the wide receive beams b1, b2, and / or b3. UE 104 can perform beam scanning on one or more of the wide receive beams. For example, according to the beam scan, UE 104 can receive beamforming communications sequentially from each of TRP 102a and TRP 102b (e.g., in the following order). For example, reference signals RS-1 to RS-4 from TRP 102a may first be received by the wide receive beam b1 of UE 104, then by the wide receive beam b2 of UE 104, and finally by the wide receive beam b3 of UE 102a. Alternatively, UE 104 may then perform a beam scan to receive reference signals RS-6 to RS-8 associated with TRP 102b via the three wide receive beams b1 to b3. In other examples, one or more of TRP 102a or TRP 102b may use different numbers of wide transmit beams to transmit the reference signals, and UE 104 may also use different numbers of wide receive beams to receive the reference signals. It should be understood that, in addition to the scanning operations described above, other beam scanning operations (e.g., beam scanning sequences) can be used to support beamforming communication. Furthermore, it should be understood that although the above examples are described with reference to two TRPs 102, beam operations (e.g., beam scanning) can support more than two TRPs, etc.

[0080] When digital beamforming is employed, TRP 102 can simultaneously transmit reference signals on its wide beams, and each TRP 102 can transmit beams sequentially, such that only one TRP 102 transmits the reference signal at a time. For example, TRP 102a can simultaneously transmit wide beams 301, 302, 303, and 304, and after transmitting these beams, TRP 102b can simultaneously transmit wide beams 305, 306, 307, and 308. In this embodiment, all TRPs 102 can periodically scan their wide beams, which also serves purposes other than beam management, such as providing initial access for UE 104 entering the network. For example, in NR, synchronization signal (SS) bursts can be transmitted at 20 ms intervals. During each SS burst transmission, TRP 102 scans multiple beams. In this embodiment, each TRP 102 periodically transmits the reference signal by scanning its wide beam. Each TRP 102 may be associated with one or more cells. The network can determine which TRPs 102 belong to the set of TRPs that transmit wide beams to a specific UE 104.

[0081] TRP 102 may use a first set of reference signal resources to transmit wide-beam reference signals. For example, in one embodiment, the reference signal is a set of SS signals transmitted via physical broadcast channel (PBCH) resources. In another embodiment, the reference signal includes a set of tracking reference signals (TRS). In one embodiment, the reference signal is a TRS corresponding to a set of channel state information (CSI) RS resources configured with tracking parameters. Another example of a reference signal resource is a first non-zero power (NZP) CSI-RS resource set. Wide-beam transmission may include these reference signals and reference signal resources, or one or more other reference signals and resources known in the art.

[0082] The received data corresponds to the TRP The Transmitting a wide beam and by UE 104's The signal received by a wide beam can be represented as

[0083] (1)

[0084] in It is TRP The transmission power, It is a reference symbol. It is additive noise, and It is TRP The channel matrix coefficients between the channel and UE 104. Without loss of generality, we assume that for the... , The reference symbol should be equal to TRP The received signals of all transmitting and receiving beams can be represented in matrix form as follows:

[0085] (2)

[0086] in It receives the combined vector matrix. It is the transmit beam steering vector matrix, and It has the characteristics of The given additive noise matrix of the elements.

[0087] In obtaining measurement values , Then, UE 104 can estimate the channel coefficient matrix. , Channel estimation can be performed using one of the following example channel models. One example channel model is a dual-polarization MIMO channel model. In this model, the dual-polarization multipath MIMO channel matrix can be modeled as follows:

[0088] (3)

[0089] in It is the number of paths in a multipath channel environment. It is the coefficient matrix between the horizontal / vertical polarization of the transmitting antenna element and the horizontal / vertical polarization of the receiving antenna element. and These are paths The angle of arrival (AoA) and the angle of departure (DoA). Here and These are UE 104 and TRP. The array response vectors are defined as follows:

[0090]

[0091] and

[0092]

[0093] in Indicates the carrier wavelength. The element representing the UE 104 antenna array 3D coordinates Indicates TRP The antenna array of the first The 3D coordinates of the element, and This represents the Euclidean inner product.

[0094] If the antenna array is a uniform linear array (ULA), then the "effective" AoA or AoD is a scalar angle; if the antenna array is a uniform planar array (UPA), then the effective AoA or AoD can be a two-dimensional vector consisting of the azimuth and zenith angles relative to the array plane. The above formulas cover these special cases.

[0095] In a MIMO multipath channel with multiple transmit and receive antennas, the number of paths... Typically much smaller than the channel size, especially in higher frequency bands where path loss attenuation is significant, i.e. This is known as channel sparsity. Embodiments of this disclosure can use channel sparsity to estimate a narrow beam corresponding to a wide beam transmitted by the TRP.

[0096] To take advantage of channel sparsity, the channel can be described as a linear combination of wavefronts corresponding to dense AoA and AoD grids. For this purpose, the two dense angular grids corresponding to AoA and AoD are defined as follows: and ,in and The typical values ​​for these grids are... or and or Then the channel can be represented as

[0097] (4)

[0098] in It corresponds to the angle of arrival. and starting angle The path coefficient matrix of the associated paths.

[0099] The main difference between the expressions in equations (3) and (4) is that the nonlinear dependence of the channel on AoA and AoD is eliminated. Furthermore, the same AoD grid can be used for all TRPs because the vector... Cross AoA-AoD space. This expression can be achieved by defining the AoA-AoD mesh as... and define , To further simplify, using these definitions, we can write:

[0100] (5)

[0101] in With simplified index same.

[0102] When utilizing channel sparsity, the measurement operator can be defined as:

[0103]

[0104] It will TRP The channel matrix is ​​mapped to the TRP and the measurement values ​​obtained by the wide beam at UE 104, (From equation (2). If all TRPs use the same wide transmit beam and have the same transmit power, then we get...) Since the channel is sparse, we can use the enhancement coefficient... , The sparsity is used to estimate the channel from the measurements. For This can typically be formulated as the following optimization problem:

[0105]

[0106] The constraints are

[0107] in Denotes the Frobenius norm. express The pseudonorm is the number of non-zero elements in its counting vector, and To design sparse order parameters, constraints are required to ensure that the parameter does not exceed [a certain value]. The matrix coefficients have non-zero elements.

[0108] There are ways to solve convex optimization problems, for example, by using... Norm minimization and its variants are other ways to enhance the sparsity of estimated channel coefficients. Norm minimization does not necessarily require a strictly sparse solution, but its optimal solution will have a few coefficients with large values ​​and the rest close to zero. Another approach is to use a greedy algorithm, which sequentially searches for the non-zero coefficients that contribute the most to the measurement. One such algorithm is called Orthogonal Matching Pursuit (OMP).

[0109] A generalized form of OMP, adjusted to recover matrix coefficients (rather than scalar coefficients), can be used due to its lower complexity. This method can be implemented using the following steps:

[0110] 1. Input: Matrix , Operator sparse order

[0111] 2. Set the "Residual Matrix" to...

[0112] 3. Set the "Index Set" to This set will store the indices of the non-zero matrix coefficients.

[0113] 4. Set the iteration counter .

[0114] 5. Find The index of the element that is most correlated with the measured value, i.e.

[0115] .

[0116] 6. Update the index set to .

[0117] 7. Update coefficient estimates:

[0118]

[0119] for , .

[0120] The optimization at this step is for a regression problem that can be solved efficiently.

[0121] 8. Calculate the residual matrix as follows:

[0122]

[0123] 9. Settings Then proceed to step 5. If Then stop.

[0124] 10. Output: Estimated coefficients .

[0125] For all This algorithm can be run. The optimization coefficients obtained by running the above algorithm are expressed as: The channel estimated after running the above algorithm is represented as:

[0126] .

[0127] The number of iterations in this algorithm is This is an assumed sparsity order. If the channel is known to be very sparse, such as in higher frequency bands, This can be set to a smaller value, which allows the algorithm to run quickly. In this case, the algorithm runs only one iteration.

[0128] After estimating the channel between each TRP and the UE, UE 104 uses channel estimation to estimate the received power when a narrow beam is applied at the transmitter and receiver. Similar to Equation (1), derived from the TRP... The Narrow transmit beam and transmitted by the UE at 104. The signal received by a narrow receiving beam can be represented as:

[0129]

[0130] in It uses TRP Narrow beam Reference symbol for launch, It is TRP The transmit power of the reference signal, and It is a noise vector. Because UE 104 cannot directly access... Therefore, it will use the estimated channel to calculate the received power for each pair of narrow transmit and receive power, given by the following formula.

[0131]

[0132] After estimating the power of all narrow beam pairs, UE 104 can use this information to inform the network how to improve the transmit beam. In the traditional BM framework, UE 104 reports an indication to the network of the optimal transmit wide beam. During beamforming in the initial access phase, the indication is implicitly reported: each SS block is associated with a corresponding random access timing and preamble. Alternatively, each SS block is associated with a different beam. By sending a random access transmit at a specific timing, UE 104 can inform the network which transmit beam it prefers, since that timing is dedicated to an SS block corresponding to that transmit beam.

[0133] For multi-TRP transmission, this is equivalent to reporting one beam per TRP 102. However, using conventional procedures to improve beams incurs significant overhead because each TRP must scan many narrow beams that collectively cover the spatial range of its reported beam.

[0134] Conversely, in embodiments of this disclosure, UE 104 utilizes information obtained by estimating the power of narrow beam pairs and can report an indication of the number of candidate “beam groups” that the network may transmit in the next round.

[0135] A beam group comprises a set of beams, each transmitted from a corresponding TRP 102. To report candidate beam groups, UE 104 can first determine the receive wide beam with the highest total power received from the transmitted beams based on the power estimated by UE 104. The index of this receive beam can be represented as...

[0136] .

[0137] UE 104 can report beams Indication of the best transmitted beam received. Below are two examples of report indications.

[0138] In the first example, UE 104 transmits with the maximum estimated power per TRP. The index of each beam. Keep it small to limit reporting costs, for example These beams can be used to target each... collection Perform sorting and obtain Choose from the index of the maximum value. The index can be referred to as the beam identifier received by UE 104. This reporting method gives the network the flexibility to select beam groups of arbitrary sizes based on its capabilities and constraints (such as scheduling). For example, when TRP 102 transmits to another UE 104 using a specific beam, the network can refuse to include that beam in the beam group. In such embodiments, UE 104 can transmit an indication that individually indicates at least one candidate narrow beam for each TRP 102 in the TRP set.

[0139] In the second example, UE 104 reported beam group ,in It is the number of beams within the group, and for all , , The criteria for selecting these beam groups can be beams. The sum of power received from the beams contained in the group. The beam with the highest total transmit power can be selected. The group reports to the network. In such embodiments, UE 104 may transmit an indication to the network indicating multiple beam groups, each beam group including candidate narrow beams associated with a corresponding TRP 102 in the TRP set.

[0140] The second example may incur greater overhead compared to the first example, but it can send more information to the network about which beam groups are likely to carry the maximum power. To provide this flexibility in the first example, UE 104 can additionally send an indication of the estimated power value for each reported beam, or send an indication of the order of the estimated power of the reported beams. In this way, the network can decide which beams to include in the beam group based on which beams transmit the highest power.

[0141] After receiving beamgroup indication or individual beam indication for each TRP 102, along with possible estimated power values ​​or estimated power orderings for the beamgroups or individual beams, the network executes the second phase. In this phase, the network jointly transmits beamgroup sets from its TRPs, where each beamgroup is associated with a portion of a set of reference signal resources.

[0142] A specific beamgroup transmitted by the network may differ from the beamgroup reported by UE 104. For example, the network may include other beams, exclude some beams from the group, or typically select to transmit a completely different beamgroup not included in the set of beamgroups reported by UE 104 due to scheduling constraints, for example. However, in some embodiments, most or all of the beamgroups transmitted to UE 104 include the beams reported from UE 104 to the network. In some cases, the beamgroup transmitted by the network may be the same as the beamgroup reported by UE 104 to the network. The network may preferentially use the beamgroup reported by UE 104 when transmitting beamgroups to UE 104.

[0143] UE 104 can use the fixed wide beam discussed above. The UE 104 receives a reference signal from the beam group. In an embodiment, for each beam group, the UE 104 measures the received power and then reports the maximum power to the network. Indication of each reference signal associated with a beam group.

[0144] UE 104 can use a wide receive beam to receive beam groups from TRP 102, allowing UE 104 to receive beams from more directions. This helps in measuring and comparing received power from different transmit beam groups. If a narrow beam is used, UE 104 can receive power from fewer directions.

[0145] Figure 3 This illustrates how, according to various aspects of this disclosure, UE 104 receives a narrow beam group from TRP 102 (in... Figure 3 This is also represented as an example of BG. Figure 3 In the example, UE 104 receives four different beam groups BG 1, BG 2, BG 3, and BG 4 from TRP 102a and TRP 102b. Each of beam groups BG 1, BG 2, BG 3, and BG 4 includes a narrow beam (also referred to as a narrow transmit beam) from each TRP in the TRP 102 set that transmits the beam group to UE 104. Although Figure 3 Only two TRP102s are shown, but more TRPs can emit narrow beams in a beam group. That is, each beam group may include at least one narrow beam from each of the multiple TRP102s or TRP sets.

[0146] The narrow beams in beamgroups BG 1, BG 2, BG 3, and BG 4 may include reference signals transmitted on a second reference signal resource set. This second reference signal resource set may differ from... Figure 2 The reference signal resources seen herein are used for wide-beam transmission from TRP 102. Figure 3Examples of reference signal resources for medium-narrow beam transmission include NZP CSI-RS resource sets, reference signal resource sets configured with joint transmission parameters, demodulation reference signal (DMRS) sets, or combinations of these resources. Embodiments are not limited to these specific examples.

[0147] exist Figure 3 In the embodiment shown, UE 104 uses a wide beam b2 to receive narrow beams from beamgroups BG1, BG2, BG3, and BG4 from TRP 102. In the analog domain, the first TRP 102a transmits a narrow beam from beamgroup BG1, and the second TRP 102b simultaneously transmits a second narrow beam from beamgroup BG1, so that UE 104 receives narrow beams from both TRPs simultaneously. In the time domain, each narrow beamgroup BG1, BG2, BG3, and BG4 can be sequentially cycled until all beamgroups have been transmitted. Although Figure 3 The example shows only four beam groups, but the number of beam groups can be greater than or less than four.

[0148] In some embodiments, the network may exclude one or more of the TRPs 102 reported by UE 104 from the actual TRPs transmitting narrow beam groups. Therefore, the number of TRPs 102 transmitting 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 UE 104 to the network.

[0149] Additionally, UE 104 can report an indication of the received power from each reference signal. This power can be the aggregated received power from all beams in the beamgroup. For example, the power can be measured as the L1-RSRP of the received combined signal transmitted from the beams in the beamgroup. The method of reporting the received power may be the same as or similar to conventional beam management specifications, where the UE reports the L1-RSRP of the strongest beamgroup, and then for each... The UE reports the difference between the L1-RSRP received from the beam group and the L1-RSRP of the strongest beam group.

[0150] In some embodiments, each of one or more beam groups transmits with different time / frequency resource sets in a time slot / RB layout, such that two different beam groups transmit with different time resources, frequency resources, or combinations thereof.

[0151] In one embodiment, the UE transmits a CSI report, which includes at least one of a resource indicator associated with a selected beam, the received power of a corresponding reference signal, or the received signal and interference-plus-noise (SINR) of a corresponding reference signal. After receiving feedback from the UE, the network designates a beam group to be used for downlink transmission.

[0152] Figure 4 An example of selecting a receive beam for communication with TRP 102 according to various aspects of this disclosure is shown. After the network has assigned at least one beam group for downlink communication, UE 104 can determine a receive beam for receiving downlink transmissions from multiple TRPs 102, while the transmit beam group is fixed. Figure 4 In the example, only two TRPs 102 are shown, but it should be understood that the number of TRPs may be greater than two. UE 104 determines the receive beam used to receive downlink transmissions from multiple TRPs 102, which may be referred to as the third stage.

[0153] During this phase, UE 104 may be configured with a set of downlink reference signals transmitted by the same beam group. As described above, the beam group contains at least one narrow beam associated with each TRP 102 in the TRP set.

[0154] exist Figure 4 In the embodiment shown, UE 104 scans its receive beams b1, b-2, b-3, and b4, measures the received reference signal, and selects the receive beam with the highest L1-RSRP. In various embodiments, UE 104 may scan different beam sets. For example, UE 104 may scan a wide receive beam. or narrow beam or and Both, or coverage Figure 3 The UE104 uses a subset of beams with a fixed angular span for the receiving beam b2. Depending on the direction of the transmit beam group and the receive power, the UE104 can use either a wide or narrow beam to establish a connection.

[0155] In some embodiments, UE 104 may skip one or more aspects of determining the received beam as described above. For example, UE 104 may use the same wide beam used to measure the beam group from TRP 102 to measure subsequent downlink transmissions from those TRPs.

[0156] In some embodiments, aspects of the various steps described above may be combined. For example, such as Figure 3 The transmit / receive beamgroups shown in (Phase Two) can be used in conjunction with determined... Figure 4The receive beam combination of UE 104 shown in (Phase 3) is illustrated. In such embodiments, UE 104 can scan receive beam sets corresponding to one or more beam groups transmitted on different time and / or frequency resources. In one example, one or more beam groups are repeatedly transmitted in multiple time slots, wherein UE 104 applies a different receive beam in each of the multiple time slots. UE 104 can report the index of a selected beam group after multiple time slots, wherein the UE also selects the receive beam associated with the selected beam group.

[0157] After determining the optimal receive beam, UE 104 can report the receive beam index to the network. For example, if a beam mapping exists, this operation can be used for subsequent uplink transmissions. In this case, UE 104 can also use the optimal receive beam as the optimal transmit beam in the uplink, and thus the network will know the UE's transmit beam.

[0158] Figure 5 An example of a UE 500 according to various aspects of this disclosure is shown. The UE 500 may include a processor 502, a memory 504, a controller 506, and a transceiver 508. The processor 502, memory 504, controller 506, or transceiver 508, or various combinations thereof, or various components thereof, may be examples of components for performing various aspects of this disclosure, as described herein. These components may be coupled via one or more interfaces (e.g., operatively, communicatively, functionally, electronically, or electrically).

[0159] Processor 502, memory 504, controller 506, or transceiver 508, or various combinations or components thereof, may be implemented in hardware (e.g., a circuit system). The hardware may include a processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof, configured to or otherwise supporting components for performing the functions described in this disclosure.

[0160] Processor 502 may include intelligent hardware devices (e.g., a general-purpose processor, DSP, CPU, ASIC, FPGA, or any combination thereof). In some embodiments, processor 502 may be configured to operate memory 504. In some other embodiments, memory 504 may be integrated into processor 502. Processor 502 may be configured to execute computer-readable instructions stored in memory 504 to cause UE 500 to perform various functions of this disclosure.

[0161] Memory 504 may comprise volatile or non-volatile memory. Memory 504 may store computer-readable, computer-executable code, including instructions that, when executed by processor 502, cause UE 500 to perform various functions as described herein. The code may be stored in non-transitory computer-readable media, such as memory 504 or other types of memory. Computer-readable media includes both non-transitory computer storage media and communication media, including any media that facilitates the transfer of computer programs from one location to another. Non-transitory storage media may be any available media accessible to a general-purpose computer or a special-purpose computer.

[0162] In some implementations, processor 502 and memory 504 coupled to processor 502 may be configured to cause UE 500 to perform one or more of the functions described herein (e.g., processor 502 executing instructions stored in memory 504). For example, processor 502 may support wireless communication of UE 500 according to the examples disclosed herein. UE 500 may be configured to support components for performing: receiving configuration messages for beam management procedures, receiving a first reference signal on a first reference signal resource set in wide-beam transmission from multiple transmit-receive points (TRPs), determining at least one candidate narrow beam for each TRP in a set of multiple TRPs, and transmitting a first indication to a network entity indicating at least one candidate narrow beam for each TRP in the set of TRPs.

[0163] Controller 506 manages the input and output signals of UE 500. Controller 506 can also manage peripheral devices not integrated into UE 500. In some embodiments, controller 506 may utilize an operating system such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some embodiments, controller 506 may be implemented as part of processor 502.

[0164] In some embodiments, UE 500 may include at least one transceiver 508. In other embodiments, UE 500 may have more than one transceiver 508. Transceiver 508 may represent a wireless transceiver. Transceiver 508 may include one or more receiver chains 510, one or more transmitter chains 512, or a combination thereof.

[0165] Receiver chain 510 may be configured to receive signals (e.g., control information, data, data packets) via wireless media. For example, receiver chain 510 may include one or more antennas for receiving signals over the air or wireless media. Receiver chain 510 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. Receiver chain 510 may include at least one demodulator configured to demodulate the received signal and obtain the transmitted data by reversing the modulation technique applied during signal transmission. Receiver chain 510 may include at least one decoder for decoding the demodulated signal to receive the transmitted data.

[0166] Transmitter chain 512 can be configured to generate and transmit signals (e.g., control information, data, data packets). 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). 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 a wireless medium. Transmitter chain 512 may also include one or more antennas for transmitting the amplified signal over the air or into the wireless medium.

[0167] Figure 6 An example of a processor 600 according to various aspects of this disclosure is shown. Processor 600 may be an example of a processor configured to perform various operations according to the examples described herein. Processor 600 may include a controller 602 configured to perform various operations according to the examples described herein. Processor 600 may optionally include at least one memory 604, for example, said at least one memory may be an L1 / L2 / L3 cache. Additionally, or alternatively, processor 600 may optionally include one or more arithmetic logic units (ALUs) 606. One or more of these components may be electronically communicated or otherwise coupled (e.g., operationally, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses).

[0168] Processor 600 may be a processor chipset and includes a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receive, acquire, retrieve, transmit, output, forward, store, determine, identify, access, write, read) according to the examples described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to the processor chipset (e.g., processor 600) or contained within the processor chipset) 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), etc.).

[0169] The controller 602 can be configured to manage and coordinate various operations of the processor 600 (e.g., signal transmission, reception, acquisition, retrieval, transmission, output, forwarding, storage, determination, identification, access, writing, and reading) to enable the processor 600 to support various operations according to the examples described herein. For example, the controller 602 can operate as a control unit of the processor 600, generating control signals to manage the operation of various components of the processor 600. These control signals include enabling or disabling functional units, selecting data paths, initiating memory accesses, and coordinating the timing of operations.

[0170] Controller 602 may be configured to fetch (e.g., fetch, retrieve, receive) instructions from memory 604 and determine subsequent instructions to be executed, enabling processor 600 to support various operations according to the examples described herein. Controller 602 may be configured to track the memory addresses of instructions associated with memory 604. Controller 602 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, controller 602 may be configured to interpret instructions and determine control signals to be output to other components of processor 600, enabling processor 600 to support various operations according to the examples described herein. Additionally, or alternatively, controller 602 may be configured to manage data flow within processor 600. Controller 602 may be configured to control data transfers between registers, arithmetic logic unit (ALU), and other functional units of processor 600.

[0171] Memory 604 may include one or more caches (e.g., memory or other memory located locally in or included in the processor 600, such as RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc.). In some embodiments, memory 604 may reside inside or on the processor chipset (e.g., locally in the processor 600). In some other embodiments, memory 604 may reside outside the processor chipset (e.g., remotely from the processor 600).

[0172] Memory 604 may store computer-readable, computer-executable code, including instructions that, when executed by processor 600, cause processor 600 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium (e.g., system memory or another type of memory). Controller 602 and / or processor 600 may be configured to execute the computer-readable instructions stored in memory 604 to cause processor 600 to perform various functions. For example, processor 600 and / or controller 602 may be coupled to or coupled to memory 604, and processor 600, controller 602, and memory 604 may be configured to perform the various functions described herein. In some examples, processor 600 may include multiple processors, and memory 604 may include multiple memories. One or more of the multiple processors may be coupled to one or more of the multiple memories, which may be individually or collectively configured to perform the various functions described herein.

[0173] One or more ALUs 606 can be configured to support various operations according to the examples described herein. In some embodiments, one or more ALUs 606 may reside within or on a processor chipset (e.g., processor 600). In some other embodiments, one or more ALUs 606 may reside outside the processor chipset (e.g., processor 600). One or more ALUs 606 can perform one or more calculations on data, such as addition, subtraction, multiplication, and division. For example, one or more ALUs 606 can receive input operands and operation codes that determine the operation to be performed. One or more ALUs 606 are configured with various logic and arithmetic circuitry, including adders, subtractors, shifters, and logic gates, to process and manipulate data according to the operation. Alternatively, one or more ALU 606s may support logical operations such as AND, OR, XOR, NOR, and NAND, thereby enabling one or more ALU 606s to handle conditional operations, comparisons, and bitwise operations.

[0174] Processor 600 may support wireless communication according to the examples disclosed herein. Processor 600 may be configured or operable to support components for performing the following operations: receiving configuration messages for beam management procedures, receiving a first reference signal on a first set of reference signal resources in a wide-beam transmission from a plurality of transmit-receive points (TRPs), determining at least one candidate narrow beam for each TRP in a set of TRPs among the plurality of TRPs, and transmitting to a network entity a first indication indicating at least one candidate narrow beam for each TRP in the set of TRPs.

[0175] Figure 7 Examples of NE 700 according to various aspects of this disclosure are shown. NE 700 may include a processor 702, a memory 704, a controller 706, and a transceiver 708. The processor 702, memory 704, controller 706, or transceiver 708, or various combinations thereof, or various components thereof, may be examples of components for performing various aspects of this disclosure described herein. These components may be coupled via one or more interfaces (e.g., operating, communicating, functional, electronic, or electrical).

[0176] Processor 702, memory 704, controller 706, or transceiver 708, or various combinations or components thereof, may be implemented in hardware (e.g., a circuit system). The hardware may include a processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof, configured to or otherwise supporting components for performing the functions described in this disclosure.

[0177] Processor 702 may include intelligent hardware devices (e.g., a general-purpose processor, DSP, CPU, ASIC, FPGA, or any combination thereof). In some embodiments, processor 702 may be configured to operate memory 704. In some other embodiments, memory 704 may be integrated into processor 702. Processor 702 may be configured to execute computer-readable instructions stored in memory 704 to cause NE 700 to perform various functions of this disclosure.

[0178] Memory 704 may comprise volatile or non-volatile memory. Memory 704 may store computer-readable, computer-executable code, including instructions that, when executed by processor 702, cause NE 700 to perform the various functions described herein. The code may be stored in non-transitory computer-readable media, such as memory 704 or other types of memory. Computer-readable media includes both non-transitory computer storage media and communication media, wherein the communication media includes any media that facilitates the transfer of a computer program from one place to another. Non-transitory storage media may be any available media accessible to a general-purpose computer or a special-purpose computer.

[0179] In some implementations, processor 702 and memory 704 coupled to processor 702 may be configured to cause NE 700 to perform one or more of the functions described herein (e.g., processor 702 executing instructions stored in memory 704). For example, processor 702 may support wireless communication at NE 700 according to the examples disclosed herein. NE 700 may be configured to support components for performing: receiving configuration messages for beam management procedures, receiving a first reference signal on a first set of reference signal resources in wide-beam transmission from a plurality of transmit-receive points (TRPs), determining at least one candidate narrow beam for each TRP in a set of TRPs, and transmitting a first indication to a network entity indicating at least one candidate narrow beam for each TRP in the set of TRPs.

[0180] Controller 706 manages the input and output signals of NE 700. Controller 706 can also manage peripheral devices not integrated into NE 700. In some embodiments, controller 706 may utilize an operating system such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some embodiments, controller 706 may be implemented as part of processor 702.

[0181] In some embodiments, the NE 700 may include at least one transceiver 708. In other embodiments, the NE 700 may have more than one transceiver 708. The 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.

[0182] Receiver chain 710 may be configured to receive signals (e.g., control information, data, packets) via wireless media. For example, receiver chain 710 may include one or more antennas for receiving the signals via air or wireless media. Receiver chain 710 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. Receiver chain 710 may include at least one demodulator configured to demodulate the received signal and obtain the transmitted data by reversing the modulation technique applied during signal transmission. Receiver chain 710 may include at least one decoder for decoding the demodulated signal to receive the transmitted data.

[0183] Transmitter chain 712 can be configured to generate and transmit signals (e.g., control information, data, data packets). 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). 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 a wireless medium. Transmitter chain 712 may also include one or more antennas for transmitting the amplified signal over the air or into the wireless medium.

[0184] Figure 8 A flowchart illustrating a method according to various aspects of this disclosure is provided. The operation of the method can be implemented by a UE as described herein. In some embodiments, the UE can execute a set of instructions to control functional elements of the UE to perform the described functions.

[0185] At 802, the method may include receiving a configuration message for a beam management procedure. Operation of 802 may be performed according to examples as described herein. In some embodiments, aspects of the operation of 802 may be described by reference to... Figure 5 The UE is described in the following instructions. Configuration messages can be, for example, CSI configuration settings.

[0186] At 804, the method may include receiving a first reference signal set from a TRP set via a wide beam set during a beam management procedure, wherein the first reference signal set is associated with a first reference signal resource set, and wherein each beam in the wide beam set is associated with a corresponding beam identifier. Operation of 804 may be performed according to examples as described herein. In some embodiments, aspects of the operation of 804 may be determined by reference... Figure 5 The UE execution described.

[0187] At 806, the method may include selecting at least one candidate narrow beam based at least in part on a first reference signal set received via a wide beam set. Operation of 806 may be performed according to the examples described herein. In some embodiments, aspects of operation of 806 may be determined by reference... Figure 5 The UE execution described.

[0188] At 808, the method may include transmitting a report to a network entity indicating at least one candidate narrow beam. Operation of 808 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 808 may be described by reference to... Figure 5 The UE execution described.

[0189] It should be noted that the methods described herein describe possible implementations, and the operations and steps may be rearranged or otherwise modified, and other implementations are possible.

[0190] The description provided herein is intended to enable those skilled in the art to make or use this disclosure. Various modifications to this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but is given the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A user equipment (UE) for wireless communication, comprising: At least one memory; and At least one processor, coupled to and configured to enable the UE to: Receive configuration messages for the beam management procedure; During the beam management procedure, a first reference signal set is received from a transmit-receive point (TRP) set via a wide beam set, wherein the first reference signal set is associated with a first reference signal resource set, and wherein each beam in the wide beam set is associated with a corresponding beam identifier. At least one candidate narrow beam is selected based at least in part on the first reference signal set received via the wide beam set; and Transmit a report to the network entity indicating at least one candidate narrow beam.

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

3. The UE of claim 2, wherein the report indicates at least one of the received power and the signal-to-interference-plus-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 a corresponding TRP in the TRP set.

5. The UE according to claim 1, wherein the configuration message indicates a first UE codebook for wide beam transmission and a second UE codebook for narrow beam transmission.

6. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to: Receive a second reference signal set from a narrow beam set, the narrow beam set including narrow beams from the TRP set; Measure the power value of the narrow beam set; and A second instruction is transmitted to the network entity, the second instruction indicating that the narrow beam group focuses on at least one narrow beam group with the 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, the CSI report including at least one of a resource indicator associated with at least one of the narrow beam groups, the received power of the second reference signal, and the received SINR of the second reference signal.

9. The UE of claim 6, wherein the second reference signal is associated with one or more of the following: Non-zero power CSI resource set Resource sets configured with joint launch parameters, and Demodulation reference signal DMRS set.

10. The UE of claim 1, wherein the first reference signal set is associated with one or more of the following: Synchronization signal SS block, Tracking reference signal TRS, and First non-zero power CSI resource set.

11. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to: Receive a third reference signal set from a single narrow beam group, the single narrow beam group comprising one or more narrow beams each associated with a TRP in the second TRP set; and Select a receive beam from a plurality of receive beams for communicating with the second TRP set.

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

13. A processor for wireless communication, comprising: At least one controller, coupled to at least one memory and configured to enable the processor to: Receive configuration messages for the beam management procedure; During the beam management procedure, a first reference signal set is received from a transmit-receive point (TRP) set via a wide beam set, wherein the first reference signal set is associated with a first reference signal resource set, and wherein each beam in the wide beam set is associated with a corresponding beam identifier. At least one candidate narrow beam is selected based at least in part on the first reference signal set received via the wide beam set; and Transmit a report to the network entity indicating at least one candidate narrow beam.

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

15. A method performed by a user equipment (UE), the method comprising: Receive configuration messages for the beam management procedure; During the beam management procedure, a first reference signal set is received from a transmit-receive point (TRP) set via a wide beam set, wherein the first reference signal set is associated with a first reference signal resource set, and wherein each beam in the wide beam set is associated with a corresponding beam identifier. At least one candidate narrow beam is selected based at least in part on the first reference signal set received via the wide beam set; and Transmit a report to the network entity indicating at least one candidate narrow beam.

16. The method of claim 15, further comprising: Receive a second reference signal set from a narrow beam set, the narrow beam set including narrow beams from the TRP set; Measure the power value of the narrow beam set; and A second instruction is transmitted to the network entity, the second instruction indicating that the narrow beam group focuses on at least one narrow beam group with the highest power value.

17. The method of claim 16, wherein the report indicates at least one of the received power and the signal-to-interference-plus-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 a corresponding TRP in the TRP set.

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

20. The method of claim 15, further comprising: Receive a second reference signal set from a narrow beam set, the narrow beam set including narrow beams from the TRP set; Measure the power value of the narrow beam set; and A second instruction is transmitted to the network entity, the second instruction indicating that the narrow beam group focuses on at least one narrow beam group with the highest power value.

Images