Patent Description:
However, mobile networks are facing soaring demands for mobile data as consumers increasingly utilize mobile devices to share and consume high-definition multi-media. In addition, as the capabilities of mobile devices continue to grow with advancements such as higher-resolution cameras, <NUM> video, always-connected cloud computing, and virtual/augmented reality, so does the ever-increasing demand for faster and improved connectivity. Enhancing mobile broadband services is one of the driving forces behind a fifth generation (<NUM>) wireless communications technology (which can be referred to as new radio (NR)) that is envisaged to expand and support diverse usage scenarios and applications with respect to current mobile network generations.

One aspect of the <NUM> communications technology includes the use of high-frequency spectrum bands above <NUM>, which may be referred to as millimeter wave (mmW) band, that is emerging as a <NUM> NR technology. The use of these bands is compelling as the large bandwidths available at these high frequencies enable extremely high data rates and significant increases in capacity. However, mmW bands generally lack robustness for mobile broadband applications due to increased propagation loss and susceptibility to blockage (e.g., hand, head, body, foliage, buildings or other structures).

Thus, as the demand for mobile broadband access continues to increase, further improvements in NR communications technology and beyond may be desired. <CIT> discloses a data transmission method for a base station to acquire transmission beam diversity in a wireless communication system. The data transmission method includes selecting at least two transmission beams to be used for data transmission from among multiple transmission beams corresponding to transmission beam information, if receiving the transmission beam information regarding the multiple transmission beams from a terminal, and transmitting data encoded with a predetermined orthogonalization code to the terminal via the selected at least two transmission beams. <CIT> relates to a method and an apparatus for grouping a plurality of beams into a plurality of beam groups in a wireless communication system supporting Multi-Input Multi-Output (MIMO). The method includes determining at least one preferred beam set, based on a channel between a plurality of transmission beams of a Base Station (BS) and a plurality of reception beams of a Mobile Station (MS), transmitting information on the at least one preferred beam set, to the BS, generating information indicating interference that at least one transmission beam of the BS exerts to the MS, based on a preferred reception beam comprised in the at least one preferred beam set, and transmitting the generated interference information to the B
<CIT> discloses a transmitting apparatus forming a plurality of transmission beams by using a plurality of antennas. Transmission beams, the correlation of which is low and the reception quality of which is high, are selected. First data stream is transmitted by using one of the selected transmission beam, and second data stream is transmitted by using the other selected transmission beam.

The underlying problem of the present invention is solved by the subject matter of the independent claims. Aspects of the present disclosure provide techniques to improve reliability and robustness for mmW systems in <NUM> NR communications technology by allowing the base station to group a plurality of mmW beams for communication with the user equipment (UE) such that the selected beam(s) for communication are independent and uncorrelated. Particularly, the techniques outlined herein allow for selection of beams that ensure macro-diversity in that the joint blocking probability of the selected beam(s) may be minimized and the susceptibility to blockage is reduced in comparison to the current systems.

As discussed above, one aspect of the <NUM> NR communications technology includes the use of high-frequency spectrum bands above <NUM>, which may be referred to as mmW. The use of these bands enables extremely high data rates and significant increases in data processing capacity. However, mmW bands are susceptible to rapid channel variations and suffer from severe free-space path loss and atmospheric absorption. In addition, mmW bands are highly vulnerable to blockage (e.g. hand, head, body, foliage, building penetration). Particularly, at mmW frequencies, even small variations in the environment, such as the turn of the head, movement of the hand, or a passing car, can change the channel conditions between the base station and the UE, and thus impact communication performance.

Current mmW <NUM> NR systems leverage the small wavelengths of mmW at the higher frequencies to make use of massive multiple input multiple output (MIMO) antenna arrays to create highly directional beams that focus transmitted radio frequency (RF) energy in order to attempt to overcome the propagation and path loss challenges in both the uplink and downlink links. In some implementations, a base station may transmit a plurality of directional candidate beams towards the desired UE for communication. In turn, the UE may measure Reference Signals Received Power (RSRP) of each candidate beam to identify one or more beams that maximize receiver signal to noise ratio (SNR) per Transmission Configuration Indication (TCI) state. Based on the RSRP measurements, the base station and the UE may select one or more beams from a plurality of candidate beams for use in communication. Cases where multiple TCIs or beams are chosen may be referred to as multi-TCI or multi-beam operation, and this type of operation may be used to increase reliability as the use of multiple TCIs or beams improves robustness and resilience to blocking.

Reliance on the RSRP measurements alone to select a candidate beam, however, fails to enforce beam diversity to ensure robustness against short-term and long-term fading. Specifically, if one or more candidate beams for communication are selected exclusively based on RSRP measurements performed at one instance of time, any variations in channel may cause the selected beam to be blocked from reaching the UE. For example, once a candidate beam is identified and selected, the UE may move to a new location where the selected mmW beam may be blocked by, for example, a tree, building, or even a hand movement. In such instances, not only would the selected beam, but also other beams having similar characteristics may also be blocked, as such beams typically have correlated RSRPs. The blockage of the selected mmW beams may increase communication overhead between the base station and the UE due to retransmissions requirements of the blocked signal(s).

Aspects of the present disclosure provide techniques to improve reliability and robustness for mmW systems in <NUM> NR communications technology by allowing the base station to group a plurality of mmW beams for communication with the UE such that the selected beam(s) for communication have improved independence and reduced correlation. Particularly, the techniques outlined herein allow for selection of beams that ensure macro-diversity in that the joint blocking probability of the selected beam(s) may be minimized and the susceptibility to blockage is reduced in comparison to the current systems.

For example, in one implementation, a user equipment (UE) reports to a base station (e.g., a gNB) beam indices that the UE considers are best to ensure robust reception. In this implementation, the gNB may first request beam indices from the UE for reliability, such as but not limited to via a protocol layer parameter or downlink control information (DCI) and/or a medium access control layer control element (MAC-CE). In response, the UE selects beams depending on UE capabilities and/or hardware limitations, such as based on a reliability metric, parameters, thresholds, or algorithms that may be configured for the UE. Examples of such a reliability metric, parameters, thresholds, or algorithms may be related to beam correlation information for metrics such as, but not limited to, RSRP, angle of arrival (AoA), and/or spatial correlation.

In another example, the gNB may explicitly exercise control over how the UE choses the beams by setting the reliability metric, parameters, thresholds, or algorithms for use by the UE.

In a further example, the gNB may request one or more additional reports from the UE for the purpose of determining beam groupings. The additional report may include correlation metrics or AoA information in addition to RSRPs of the beams. Based on the information in the additional reports, the gNB may group similar (e.g., substantially correlated) TCI states or beams.

Therefore, the present solutions provide for TCI state or beam grouping based on correlation of one or more beam metrics, enabling TCI states or beams to be chosen from different groupings in order to improve reliability of communications between the UE and the gNB.

Various aspects are now described in more detail with reference to the <FIG>. Additionally, the term "component" as used herein may be one of the parts that make up a system, may be hardware, firmware, and/or software stored on a computer-readable medium, and may be divided into other components.

The wireless communications system <NUM> may include one or more base stations <NUM>, one or more UEs <NUM>, and a core network. The core network may provide user authentication, access authorization, tracking, internet protocol (IP) connectivity, and other access, routing, or mobility functions. The base stations <NUM> may perform radio configuration and scheduling for communication with the UEs <NUM>, or may operate under the control of a base station controller (not shown). In various examples, the base stations <NUM> may communicate, either directly or indirectly (e.g., through core network), with one another over backhaul links <NUM> which may be wired or wireless communication links.

The base stations <NUM> may wirelessly communicate with the UEs <NUM> via one or more base station antennas. The base station <NUM> may include a communication management component <NUM> (see <FIG>) for grouping one or more mmW beams based on correlation information to ensure reliability and robustness in multi-TCI or multi-beam operations. To this end, the communication management component <NUM> may include a beam grouping component <NUM> that may either group one or more beams based on the beam indices or based on beam measurement reports received from the UE <NUM> (see <FIG>). In some aspects, the beam grouping may be achieved by identifying one or more of RSRP-correlation by RSRP-correlation component <NUM>, AoA separation by AoA separation component <NUM>, and spatial correlation by spatial correlation component <NUM> based on one or more beam measurement reports. In some aspects, the beam grouping component <NUM> may group one or more beams into a plurality of TCI states based on the characteristics and the similarities (or differences) between the plurality of the beams identified in the beam measurement report(s).

In some examples, base stations <NUM> may be referred to as a base transceiver station, a radio base station, an access point, an access node, a radio transceiver, a NodeB, eNodeB (eNB), gNB, Home NodeB, a Home eNodeB, gNodeB (gNB), a relay, or some other suitable terminology. The geographic coverage area <NUM> for a base station <NUM> may be divided into sectors or cells making up only a portion of the coverage area (not shown). The wireless communication network <NUM> may include base stations <NUM> of different types (e.g., macro base stations <NUM> or small cell base stations <NUM>, described below).

In some examples, the wireless communication network <NUM> may be or include one or any combination of communication technologies, including a NR or <NUM> technology, a Long Term Evolution (LTE) or LTE-Advanced (LTE-A) or MuLTEfire technology, a Wi-Fi technology, a Bluetooth technology, or any other long or short range wireless communication technology. The wireless communication network <NUM> may be a heterogeneous technology network in which different types of base stations provide coverage for various geographical regions. For example, each base station <NUM> may provide communication coverage for a macro cell, a small cell, or other types of cell. The term "cell" is a 3GPP term that can be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g., sector, etc.) of a carrier or base station, depending on context.

A macro cell may generally cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs <NUM> with service subscriptions with the network provider.

A small cell may include a relative lower transmit-powered base station, as compared with a macro cell, that may operate in the same or different frequency bands (e.g., licensed, unlicensed, etc.) as macro cells. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access and/or unrestricted access by UEs <NUM> having an association with the femto cell (e.g., in the restricted access case, UEs <NUM> in a closed subscriber group (CSG) of the base station <NUM>, which may include UEs <NUM> for users in the home, and the like).

The communication networks that may accommodate some of the various disclosed examples may be packet-based networks that operate according to a layered protocol stack and data in the user plane may be based on the IP. A user plane protocol stack (e.g., packet data convergence protocol (PDCP), radio link control (RLC), MAC, etc.), may perform packet segmentation and reassembly to communicate over logical channels. For example, a MAC layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use hybrid automatic repeat/request (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the RRC protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE <NUM> and the base stations <NUM>. The RRC protocol layer may also be used for core network <NUM> support of radio bearers for the user plane data. At the physical (PHY) layer, the transport channels may be mapped to physical channels.

The UEs <NUM> may be dispersed throughout the wireless communication network <NUM>, and each UE <NUM> may be stationary or mobile. The UEs <NUM> may include a beam diversity selection component <NUM> (see <FIG> and <FIG>) to perform one or more functions of beam selection in accordance with aspects of the present disclosure. In some examples, as described with reference to <FIG> and <FIG> (infra), the beam diversity selection component <NUM> may include an RSRP-correlation component <NUM> for measuring RSRP correlation between a plurality of mmW beams. The beam diversity selection component <NUM> may further include an AoA separation component <NUM> for determining AoAs of beams and identifying whether two or more beams satisfy an AoA separation threshold. The beam diversity selection component <NUM> may further include a spatial correlation component <NUM> for determining spatial correlation of beams and ensuring that two or more beams are statistically independent and distributed. Depending on the implementation, the beam diversity selection component <NUM> may include all of RSRP-correlation component <NUM>, AoA separation component <NUM>, and spatial correlation component <NUM>, while in other implementations only a subset may be included. Thus, the beam diversity selection component <NUM> operates to identify substantially uncorrelated beams such that multiple independent channels with substantially uncorrelated characteristics can be created and be used for either transmitting multiple data streams or increasing the reliability (e.g., in terms of low bit error rate).

A UE <NUM> may also include or be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. A UE <NUM> may be a cellular phone, a smart phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a smart watch, a wireless local loop (WLL) station, an entertainment device, a vehicular component, a customer premises equipment (CPE), or any device capable of communicating in wireless communication network <NUM>. Additionally, a UE <NUM> may be Internet of Things (IoT) and/or machine-to-machine (M2M) type of device, e.g., a low power, low data rate (relative to a wireless phone, for example) type of device, that may in some aspects communicate infrequently with wireless communication network <NUM> or other UEs. A UE <NUM> may be able to communicate with various types of base stations <NUM> and network equipment including macro eNBs, small cell eNBs, macro gNBs, small cell gNBs, gNB, relay base stations, and the like.

UE <NUM> may be configured to establish one or more wireless communication links <NUM> with one or more base stations <NUM>. The wireless communication links <NUM> shown in wireless communication network <NUM> may carry uplink (UL) transmissions from a UE <NUM> to a base station <NUM>, or downlink (DL) transmissions, from a base station <NUM> to a UE <NUM>. Each wireless communication link <NUM> may include one or more carriers, where each carrier may be a signal made up of multiple sub-carriers (e.g., waveform signals of different frequencies) modulated according to the various radio technologies described above. Each modulated signal may be sent on a different sub-carrier and may carry control information (e.g., reference signals, control channels, etc.), overhead information, user data, etc. In an aspect, the wireless communication links <NUM> may transmit bidirectional communications using frequency division duplex (FDD) (e.g., using paired spectrum resources) or time division duplex (TDD) operation (e.g., using unpaired spectrum resources). Frame structures may be defined for FDD (e.g., frame structure type <NUM>) and TDD (e.g., frame structure type <NUM>). Moreover, in some aspects, the wireless communication links <NUM> may represent one or more broadcast channels.

In some aspects of the wireless communication network <NUM>, base stations <NUM> or UEs <NUM> may include multiple antennas for employing antenna diversity schemes to improve communication quality and reliability between base stations <NUM> and UEs <NUM>. Additionally or alternatively, base stations <NUM> or UEs <NUM> may employ multiple input multiple output (MIMO) techniques that may take advantage of multi-path environments to transmit multiple spatial layers carrying the same or different coded data.

Wireless communication network <NUM> may also support operation on multiple cells or carriers, a feature which may be referred to as carrier aggregation (CA) or multi-carrier operation. A carrier may also be referred to as a component carrier (CC), a layer, a channel, etc. The terms "carrier," "component carrier," "cell," and "channel" may be used interchangeably herein. A UE <NUM> may be configured with multiple downlink CCs and one or more uplink CCs for carrier aggregation. The base stations <NUM> and UEs <NUM> may use spectrum up to Y MHz (e.g., Y = <NUM>, <NUM>, <NUM>, or <NUM>) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x = number of component carriers) used for transmission in each direction. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL).

The wireless communication network <NUM> may further include base stations <NUM> operating according to Wi-Fi technology, e.g., Wi-Fi access points, in communication with UEs <NUM> operating according to Wi-Fi technology, e.g., Wi-Fi stations (STAs) via communication links in an unlicensed frequency spectrum (e.g., <NUM>). When communicating in an unlicensed frequency spectrum, the STAs and AP may perform a clear channel assessment (CCA) or listen before talk (LBT) procedure prior to communicating in order to determine whether the channel is available.

Additionally, one or more of base stations <NUM> and/or UEs <NUM> may operate according to millimeter wave (mmW or mmWave) technology. For example, mmW technology includes transmissions in mmW frequencies and/or near mmW frequencies. Extremely high frequency (EHF) is part of the radio frequency (RF) in the electromagnetic spectrum. For example, the super high frequency (SHF) band extends between <NUM> and <NUM>, and may also be referred to as centimeter wave. Communications using the mmW and/or near mmW radio frequency band has extremely high path loss and a short range. As such, base stations <NUM> and/or UEs <NUM> operating according to the mmW technology may utilize beamforming in their transmissions to compensate for the extremely high path loss and short range.

<FIG> illustrates a spectrum diagram <NUM> that illustrates aspects of the frequency range in which some of the communications described herein are performed in accordance with aspects of the present disclosure. Spectrum diagram <NUM> may include the following components: electromagnetic spectrum <NUM> and environment <NUM>.

In some examples, electromagnetic spectrum <NUM> may include the following components: ultra-violet (UV) radiation <NUM>, visible light <NUM>, infrared radiation <NUM>, and radio waves <NUM>. The mmW (or extremely high frequency (EHF)) portion of the electromagnetic spectrum corresponds to electromagnetic radiation with a frequency of <NUM>-<NUM> and a wavelength between <NUM> and <NUM>. Near MMW may extend down to a frequency of <NUM> with a wavelength of <NUM> millimeters.

In some examples, radio waves <NUM> may include the following components: EHF band <NUM>, super high frequency (SHF) band <NUM>, ultra-high frequency (UHF) band <NUM>, very high frequency (VHF) band <NUM>, high frequency (HF) band <NUM>, medium frequency (MF) band <NUM>, low frequency (LF) band <NUM>, and very low frequency (VLF) band <NUM>. The EHF band <NUM> lies between the SHF band <NUM> and the far infrared band <NUM>. The SHF band <NUM> may also be referred to as the centimeter wave band. In some examples, environment <NUM> may include the following components: mmW radiation <NUM>, atmosphere <NUM>, rain <NUM>, obstacle <NUM>, and foliage <NUM>.

In some examples, the wireless communication system <NUM> may be a mmW communication system. The mmW communication systems may include transmissions in mmW frequencies and/or near mmW frequencies. In mmW communication systems (e.g., access network <NUM>), a line of sight (LOS) may be needed between a transmitting device (e.g., base station <NUM>) and a receiving device (e.g., UE <NUM>), or between two UEs <NUM>. Frequency is very high in mmW communication systems which means that beam widths are very small, as the beam widths are inversely proportional to the frequency of the waves or carriers transmitted by an antenna of the transmitting device. Beam widths used in mmW communications are often termed as "pencil beams. " The small wavelengths may result in many objects or materials acting as obstacles including even oxygen molecules. Therefore, LOS between the transmitter and receiver may be required unless a reflected path is strong enough to transmit data. Further, in some examples, base stations may track UEs <NUM> to focus beams for communication.

During LOS situations, tracking of the UE <NUM> may be performed by the base station <NUM> or another UE <NUM> by focusing a beam onto the tracked UE <NUM>. However, if the receiving UE <NUM> is in a Non-Line of Sight (NLOS) position, then a transmitter of the base station <NUM> may need to search for a strong reflected path which is not always available. An example of a UE <NUM> being in a NLOS position may include a first UE <NUM> located within a vehicle. When the first UE <NUM> is located within the vehicle, a base station <NUM> may have difficulty retaining LOS and the difficulty of retaining LOS may further increase when the vehicle is moving.

Further, compared to lower frequency communication systems, a distance between base stations <NUM> in a mmW communication system may be very short (e.g., <NUM> - <NUM> meters between gNBs). The short distances may result in a short amount of time required for a handover between base stations <NUM>. The short distance and the fast handovers may cause difficulty to the base station <NUM> in maintaining a LOS beam on a UE <NUM> when the UE <NUM> is, for example, located within a vehicle as even small obstacles like a user's finger on the UE <NUM> or the vehicle windows or windshield act as obstacles to maintaining the LOS.

Thus, as discussed above, communications using the mmW and/or near mmW radio frequency band may have extremely high path loss and a short range. Specifically, while the use of these bands is compelling as the large bandwidths available at these high frequencies enable extremely high data rates and significant increases in capacity, mmW bands are highly susceptible to rapid channel variations and suffer from severe free-space path loss and atmospheric absorption, including blockage (e.g. hand, head, body, foliage, building penetration). In other words, at mmW frequencies, even small variations in the environment, such as the turn of the head, movement of the hand, or a passing car can change the channel conditions between the base station and the UE, and thus impact performance.

As such, base stations <NUM> and/or UEs <NUM> operating according to the mmW technology may utilize beamforming (see <FIG>) in their transmissions to compensate for the extremely high path loss and short range. Particularly, the <NUM> NR systems may leverage the massive MIMO antenna arrays to create highly directional beams of small wavelengths that focus transmitted RF energy in order to attempt to overcome the propagation and path loss challenges in both the uplink and downlink. In some aspects of the wireless communication network <NUM>, base stations <NUM> or UEs <NUM> may include multiple antennas for employing antenna diversity schemes to improve communication quality and reliability between base stations <NUM> and UEs <NUM>. Thus, the base stations <NUM> or UEs <NUM> may employ MIMO techniques that may take advantage of multi-path environments to transmit multiple spatial layers carrying the same or different coded data.

<FIG> illustrates a schematic diagram <NUM> that supports beam grouping and selection procedure to ensure beam diversity in accordance with the very scope of protection of the appended set of claims. Specifically, beamforming is a technique for directional signal transmission and reception. Schematic diagram <NUM> illustrates an example of beamforming operations, and may include a base station <NUM>, beamforming array <NUM>, and UE <NUM>.

In some examples, the beamforming array <NUM> of the base station <NUM> may include one or more antennas <NUM> for employing MIMO techniques that may take advantage of multi-path environments to transmit multiple spatial layers carrying the same or different coded data. Beamforming at a transmitter (e.g., base station <NUM> or UE <NUM>) may involve phase-shifting the signal produced at different antennas <NUM> in an array to focus a transmission in a particular direction. The phase-shifted signals may interact to produce constructive interference in certain directions and destructive interference in other directions. By focusing the signal power, a transmitter may improve communication throughput while reducing interference with neighboring transmitters.

Similarly, beamforming at a receiver may involve phase-shifting a signal received from different antennas <NUM>. When combining the phase shifted signals, the receiver may amplify a signal from certain directions and reduce the signal from other directions. In some cases, receivers and transmitters may utilize beamforming techniques independently of each other. In other cases, a transmitter and receiver may coordinate to select a beam direction. The use of beamforming may depend on factors such as the type of signal being transmitted and the channel conditions. For example, directional transmissions may not be useful when transmitting to multiple receivers, or when the location of the receiver is unknown. Thus, beamforming may be appropriate for unicast transmissions, but may not be useful for broadcast transmissions. Also, beamforming may be appropriate when transmitting in a high frequency radio band, such as in the mmW band.

Since the beamforming array <NUM> size is proportional to the signal wavelength, smaller devices (e.g., UEs) may also be capable of beamforming in high frequency bands. Also, the increased receive power may compensate for the increased path loss at these frequencies. In some examples, beamforming pattern <NUM> may include one or more beams <NUM>, which may be identified by individual beam IDs (e.g., first beam <NUM>-a, second beam <NUM>-b, third beam <NUM>-c, etc.).

Generally, in systems such as <NUM> NR mmW systems, a base station <NUM> may transmit a plurality of directional candidate beams <NUM> (e.g., <NUM>-a, <NUM>-b, <NUM>-c) towards the desired UE <NUM> for communication. In turn, the UE <NUM> may measure RSRP of each candidate beam <NUM> to identify one or more beams that maximize receiver SNR per TCI state. Based on the RSRP measurements, the base station <NUM> and the UE <NUM> may select one or more beams (e.g., first beam <NUM>-a) from a plurality of candidate beams <NUM>. Cases where multiple TCIs or beams are chosen may be referred to as multi-TCI or multi-beam operation, and this type of operation may be used to increase reliability as the use of multiple TCIs or beams improves robustness and resilience to blocking.

However, as noted above, reliance on the RSRP measurements alone to select a candidate beam fails to enforce beam diversity to ensure robustness against short-term and long-term fading, as RSRP measurements alone do not identify a correlation, e.g., a similarity or difference of RSRP over time or of AoA or of spatial characteristics, between the TCI states or beams. Specifically, if one or more candidate beams <NUM> for communication are selected based on RSRP measurements performed at one instance of time, any variations in channel condition may cause the selected beams to be blocked from reaching the UE. For example, once a candidate beam is identified and selected (e.g., first beam <NUM>-a), the UE may move to a location such that the selected mmW beam may be blocked by a tree, building, or even a hand movement. In such instance, not only the selected beam <NUM>-a, but also other beams having similar characteristics (e.g., second beam <NUM>-b) that were identified as providing improved SNR may also be blocked. For example, regarding the impact of blocking, depending on the blockage model, multiple beam clusters may be affected by a single blocker and/or correlated blockers. In this case, for instance, two good/top beams may get blocked. Further, in this type of blocking situation, the effective number of beam clusters and AoA may be different before and after blocking. In any case, the blockage of the selected mmW beams in multi-TCI or multi-beam operation may increase communication overhead between the base station and the UE due to retransmissions of the blocked signal.

Aspects of the present invention provide techniques to improve reliability and robustness for mmW systems by allowing the base station <NUM> to group a plurality of mmW beams for communication with the UE <NUM> such that the selected beam(s) for communication are independent and uncorrelated. These techniques may be particularly effective in multi-TCI or multi-beam operation. It should be appreciated by those of ordinary skill in the art that the present invention is not just limited to mmW, but may also include any other frequencies used for wireless communication.

In the present embodiment of the claimed invention, in order to facilitate beam grouping per TCI state, the base station <NUM> requests beam indices from the UE for beam reliability. Moreover, the base station <NUM> requests beam measurement reports from the UE in order to facilitate beam grouping at the base station. Based on the beam indices and/or measurement reports that are received from the UE <NUM>, the base station groups one or more mmW beams into one or more TCI states. In some examples, a TCI state may indicate to a UE a transmission configuration which identifies the one or more mmW beams that the UE may configure for communication with the base station. Additionally, the TCI state may include QCL-relationships between the downlink reference signals and the Physical Downlink Shared Channel (PDSCH) demodulation reference signal (DMRS) ports. In some aspects, a single UE may be RRC configured with a plurality of M candidate TCI states for the purposes of QCL indication.

In the present embodiment of the claimed invention, in order to group the one or more mmW beams while ensuring robustness and diversity, the base station <NUM> transmits a beam diversity request <NUM> to the UE <NUM>. The beam diversity request <NUM> may include either a request for the UE to identify one or more beam indices (e.g., beam IDs) that are independent and uncorrelated such that a joint blocking probability of the selected beams is minimized. In some aspects, the UE <NUM> may select one or more beam indices from the beamforming pattern <NUM> that includes one or more beams <NUM>, which may be identified by individual beam IDs (e.g., first beam <NUM>-a, second beam <NUM>-b, third beam <NUM>-c, etc.).

Upon receiving the beam diversity request <NUM>, the UE <NUM>, and more particularly the beam diversity selection component <NUM> (see <FIG>) of the modem <NUM> in the UE <NUM>, may determine one or more of factors that may contribute towards robustness and diversity of beam selection. In the present embodiment of the claimed invention, the one or more factors include RSRP correlation and may include also angle of arrival (AoA) separation, and/or spatial correlation of the one or more beams <NUM>.

Determining RSRP correlation <NUM> may include the RSRP-correlation component <NUM> (see <FIG>) measuring, at the UE <NUM>, the RSRP of each received beam <NUM> in the beamforming pattern <NUM> at multiple instances of time during a monitoring period <NUM> (<FIG>). In some examples, the "monitoring period" may be periodic such that the measurements may be performed over time to confirm that channel conditions have not varied such that selection of new beam mav be necessitated. In contrast to the current systems that select a beam <NUM> based on a single RSRP measurement that offers the greatest SNR, features of the present disclosure measure RSRP of each received beam <NUM> over a period of time in order to identify correlation between the plurality of beams <NUM>. For example, referring to <FIG>, the UE <NUM> at a first time period (T<NUM>) may measure RSRP of the first beam <NUM>-a as <NUM> decibel (db), the second beam <NUM>-b as <NUM> db, and third beam <NUM>-c at <NUM> db. In current systems, the UE <NUM> may select the second beam <NUM>-b for communication given that the second beam <NUM>-b at the first time period provides the highest RSRP of the plurality of beams <NUM>. However, features of the present disclosure provide improvements on this system by conducting subsequent RSRP measurements of each beam <NUM> at the second time period (T<NUM>) in order to identify RSRP correlation between the beams <NUM>.

In the illustrated instance, during the second time period (T<NUM>), the RSRP measurements of the first beam <NUM>-a may be <NUM> db (Δ = -3db), the second beam <NUM>-b may be <NUM> db (Δ = -16db), and third beam <NUM>-c may be <NUM> db (Δ = -4db). Given the steep decline in the RSRP measurement between the first time period and the second time period for the second beam <NUM>-b, the UE <NUM> may be able to determine that the second beam <NUM>-b, while initially offering the strongest RSRP measurements, may be susceptible to path loss or blockage. As such, the UE <NUM> may identify the first beam <NUM>-a and the third beam <NUM>-c as beams that offer greater reliability and diversity. In some aspects, the base station <NUM> may configure the RSRP-correlation threshold and provide the RSRP-correlation threshold information to the UE <NUM>. Accordingly, the UE may report beam indices of one or more beams <NUM> that satisfy the RSRP-correlation threshold (e.g., report beams whose correlation is below the RSRP-correlation threshold).

Additionally the UE <NUM>, and more particularly the AoA separation component <NUM> (see <FIG>) of the UE <NUM>, may determine AoA separation of the two or more beams. AoA separation may include identifying two or more beams that satisfy an AoA separation threshold in order to ensure that the AoA of the first beam <NUM>-a and the third beam <NUM>-c, for example, is sufficiently different such that if the first beam <NUM>-a is blocked due to an obstacle there is a high probability of the third beam <NUM>-c may successfully reach the UE <NUM>. Indeed, if multiple beams <NUM> present similar (or close to similar) AoA (e.g., the separation is less than the AoA separation threshold), there may be a greater likelihood of joint blocking of multiple beams that may adversely impact communication performance. In some aspects, the base station <NUM> may configure the AoA separation threshold and provide the AoA separation threshold information to the UE <NUM>. Accordingly, the UE may report beam indices of one or more beams <NUM> that satisfy the AoA separation threshold (e.g., the AoA of a beam exceeds the AoA separation threshold configured by the base station <NUM> for the UE <NUM>).

Spatial correlation may refer to a signal's spatial direction and the average received signal gain of the two or more beams <NUM>. Particularly, spatial correlation may ensure that the two or more beams <NUM> are statistically independent and distributed such that multiple independent channels with identical characteristics can be created and be used for either transmitting multiple data streams or increasing the reliability (e.g., in terms of low bit error rate). To this end, spatial correlation component <NUM> (see <FIG>) may identify the spatial correlation between the two or more beams <NUM>. In some aspects, the base station <NUM> may configure the spatial-correlation threshold and provide the spatial-correlation threshold information to the UE <NUM>. Accordingly, the UE may report beam indices of one or more beams <NUM> that satisfy the spatial-correlation threshold (e.g., the UE <NUM> may report beam indices for beams whose spatial correlation is less than the spatial-correlation threshold).

Based on the calculations of one or more of RSRP correlation, AoA separation, and the spatial correlation, the UE <NUM> may identify one or more beams that the UE may consider to provide robust reception. Accordingly, UE <NUM> reports the identified beams in a beam diversity response <NUM> to the base station <NUM> such that the base station <NUM> may group the identified beams (e.g., first beam <NUM>-a and third beam <NUM>-c) into separate TCI states. The base station <NUM> further transmits TCI state information to the UE <NUM> in order allow the UE <NUM> to be configured for subsequent communication based on the beams <NUM> identified in the TCI states. It should be noted that in some examples, the UE <NUM> may be configured with multiple TCI states, each TCI state identifying one or more different beams <NUM>. In some examples, the selection of the one or more beams <NUM> based on combination of RSRP correlation, AoA separation, and the spatial correlation may be controlled by the base station <NUM> by setting one or more thresholds (e.g., RSRP-correlation threshold, AoA separation threshold, or spatial-correlation threshold) such that the reliability metrics are satisfied.

In another example, the base station <NUM> requests the UE <NUM> to provide measurement reports to the base station <NUM> that identify beam indices based on a base station-defined configuration to identify the one or more beam indices that provide greatest robustness. In such implementation, the base station <NUM> and not the UE <NUM> controls the selection and grouping of the beams into one or more TCI states based on the measurement reports that are received from the UE <NUM>. In such instance, the base station <NUM> transmits a beam diversity request <NUM> to the UE <NUM> that may request the UE <NUM> to provide beam measurement reports to the base station <NUM>. In some examples, the beam measurement reports may include one more identifiers of which metric, threshold, parameter, and/or algorithm to use, such as corresponding to the measured RSRP correlation metrics, spatial correlation metrics, and/or AoA separation or correlation of the one or more beams <NUM>. The UE <NUM> may perform measurements on each received beam <NUM> based on base station-defined metric, threshold, parameter, and/or algorithm and provide a beam measurement report in the UE beam diversity response <NUM> to the base station <NUM> via the measurement reporting component <NUM> (see <FIG>). In some instances, the UE beam diversity response <NUM> may further include information associated with the UE <NUM> hardware capabilities and limitations to assist the base station <NUM> in grouping the beams <NUM> in one or more TCI states. For example, in one option, the base station <NUM> configures an angle threshold and the UE <NUM> reports beam indices that differ by more than that configured threshold. In another option, for example, the base station <NUM> configures a threshold for RSRP-correlation and the UE <NUM> reports beams whose correlation is below the threshold. In a further option, for example, the base station <NUM> configures a threshold for a spatial correlation metric and the UE <NUM> reports beams whose correlation is below the threshold. Based on the measurement reports, the base station groups the one or more beams <NUM> into one or more TCI states in order to ensure robustness of each scheduled UE <NUM> in the coverage area <NUM> of the base station <NUM>. In some aspects, beams with "similar" characteristics (e.g., similar AoA, RSRP correlation, and/or spatial-correlation) may be grouped together into the same TCI state.

<FIG> illustrates a hardware components and subcomponents of a device that may be a UE <NUM> for implementing one or more methods (e.g., method <NUM>) described herein in accordance with various aspects of the present disclosure. For example, one example of an implementation of the UE <NUM> may include a variety of components, some of which have already been described above, but including components such as one or more processors <NUM>, memory <NUM> and transceiver <NUM> in communication via one or more buses <NUM>, which may operate in conjunction with the beam diversity selection component <NUM> to perform functions described herein related to including one or more methods (e.g., <NUM>) of the present disclosure.

In some examples, the beam diversity selection component <NUM> may include an RSRP-correlation component <NUM> for measuring RSRP correlation between a plurality of mmW beams. The beam diversity selection component <NUM> may further include an AoA separation component <NUM> for identifying whether the two or more beams satisfy AoA separation threshold configured by the base station <NUM>. The beam diversity selection component <NUM> may further include a spatial correlation component <NUM> for ensuring that the two or more beams are statistically independent and distributed such that multiple independent channels with identical characteristics can be created and be used for either transmitting multiple data streams or increasing the reliability (e.g., in terms of low bit error rate).

The one or more processors <NUM>, modem <NUM>, memory <NUM>, transceiver <NUM>, RF front end <NUM> and one or more antennas <NUM>, may be configured to support voice and/or data calls (simultaneously or non-simultaneously) in one or more radio access technologies. In an aspect, the one or more processors <NUM> can include a modem <NUM> that uses one or more modem processors. The various functions related to beam diversity selection component <NUM> may be included in modem <NUM> and/or processors <NUM> and, in an aspect, can be executed by a single processor, while in other aspects, different ones of the functions may be executed by a combination of two or more different processors. For example, in an aspect, the one or more processors <NUM> may include any one or any combination of a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receiver processor, or a transceiver processor associated with transceiver <NUM>. In other aspects, some of the features of the one or more processors <NUM> and/or modem <NUM> associated with beam diversity selection component <NUM> may be performed by transceiver <NUM>.

The memory <NUM> may be configured to store data used herein and/or local versions of application(s) <NUM> or beam diversity selection component <NUM> and/or one or more of its subcomponents being executed by at least one processor <NUM>. The memory <NUM> can include any type of computer-readable medium usable by a computer or at least one processor <NUM>, such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, the memory <NUM> may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes defining beam diversity selection component <NUM> and/or one or more of its subcomponents, and/or data associated therewith, when the UE <NUM> is operating at least one processor <NUM> to execute beam diversity selection component <NUM> and/or one or more of its subcomponents.

The transceiver <NUM> may include at least one receiver <NUM> and at least one transmitter <NUM>. The receiver <NUM> may include hardware, firmware, and/or software code executable by a processor for receiving data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). The receiver <NUM> may be, for example, a radio frequency (RF) receiver. In an aspect, the receiver <NUM> may receive signals transmitted by at least one UE <NUM>. Additionally, receiver <NUM> may process such received signals, and also may obtain measurements of the signals, such as, but not limited to, Ec/Io, SNR, RSRP, RSSI, etc. The transmitter <NUM> may include hardware, firmware, and/or software code executable by a processor for transmitting data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). A suitable example of the transmitter <NUM> may including, but is not limited to, an RF transmitter.

Moreover, in an aspect, transmitting device may include the RF front end <NUM>, which may operate in communication with one or more antennas <NUM> and transceiver <NUM> for receiving and transmitting radio transmissions, for example, wireless communications transmitted by at least one base station <NUM> or wireless transmissions transmitted by UE <NUM>. The RF front end <NUM> may be connected to one or more antennas <NUM> and can include one or more low-noise amplifiers (LNAs) <NUM>, one or more switches <NUM>, one or more power amplifiers (PAs) <NUM>, and one or more filters <NUM> for transmitting and receiving RF signals.

In an aspect, the LNA <NUM> can amplify a received signal at a desired output level. In an aspect, the RF front end <NUM> may use one or more switches <NUM> to select a particular LNA <NUM> and its specified gain value based on a desired gain value for a particular application.

Further, for example, one or more PA(s) <NUM> may be used by the RF front end <NUM> to amplify a signal for an RF output at a desired output power level. In an aspect, the RF front end <NUM> may use one or more switches <NUM> to select a particular PA <NUM> and its specified gain value based on a desired gain value for a particular application.

Also, for example, one or more filters <NUM> can be used by the RF front end <NUM> to filter a received signal to obtain an input RF signal. In an aspect, the RF front end <NUM> can use one or more switches <NUM> to select a transmit or receive path using a specified filter <NUM>, LNA <NUM>, and/or PA <NUM>, based on a configuration as specified by the transceiver <NUM> and/or processor <NUM>.

As such, the transceiver <NUM> may be configured to transmit and receive wireless signals through one or more antennas <NUM> via the RF front end <NUM>. In an aspect, the transceiver <NUM> may be tuned to operate at specified frequencies such that transmitting device can communicate with, for example, one or more base stations <NUM> or one or more cells associated with one or more base stations <NUM>. In an aspect, for example, the modem <NUM> can configure the transceiver <NUM> to operate at a specified frequency and power level based on the configuration of the transmitting device and the communication protocol used by the modem <NUM>.

In an aspect, the modem <NUM> can be a multiband-multimode modem, which can process digital data and communicate with the transceiver <NUM> such that the digital data is sent and received using the transceiver <NUM>. In an aspect, the modem <NUM> can be multiband and be configured to support multiple frequency bands for a specific communications protocol. In an aspect, the modem <NUM> can be multimode and be configured to support multiple operating networks and communications protocols. In an aspect, the modem <NUM> can control one or more components of transmitting device (e.g., RF front end <NUM>, transceiver <NUM>) to enable transmission and/or reception of signals from the network based on a specified modem configuration. In an aspect, the modem configuration can be based on the mode of the modem <NUM> and the frequency band in use. In another aspect, the modem configuration can be based on UE configuration information associated with transmitting device as provided by the network during cell selection and/or cell reselection.

<FIG> is a flowchart of an example method <NUM> for wireless communications in accordance with aspects of the present disclosure. The method <NUM> may be performed using the UE <NUM>. Although the method <NUM> is described below with respect to the elements of the UE <NUM>, other components may be used to implement one or more of the steps described herein.

At block <NUM>, the method <NUM> may include receiving, at the UE, a beam diversity request from a base station. For example, in an aspect, transceiver <NUM> may receive the beam diversity request from the RF front end <NUM> and forward the received message to the modem <NUM> of the UE <NUM>. In some examples, the beam diversity request triggers the UE to identify one or more beams that may provide robustness connectivity based on beam characteristic correlation information. In some examples, the beam diversity request from the base station may include information associated with one or more of RSRP-correlation threshold, AoA separation threshold, or spatial-correlation threshold that the beam measurements must satisfy to be included in the beam diversity response. The information associated with the one or more thresholds may be used to configure the UE to report beams that satisfy the thresholds configured by the base station. Aspects of block <NUM> may be performed by transceiver <NUM> described with reference to <FIG>.

At block <NUM>, the method <NUM> may include performing beam measurements for a plurality of directional candidate beams transmitted by the base station towards the UE based in part on the beam diversity request. In some examples, the beam measurements may include beam characteristic correlation information for the plurality of directional candidate beams. The beam characteristic correlation information for the plurality of directional candidate beams may include one or more of RSRP correlation information, AoA separation information, or spatial correlation information for the plurality of directional candidate beams. It should be appreciated that additional factors that may affect correlation in the UE receiving a beam from the base station may also be considered in beam measurements. Aspects of block <NUM> described above may be performed by beam diversity selection component <NUM> described with reference to <FIG>. Specifically, the beam diversity selection component <NUM> may include an RSRP-correlation component <NUM> to measure the RSRP of each received beam over a plurality of time periods in order to identify RSRP correlation between a plurality of beams.

In some examples, performing the beam measurements may include determining whether the one or more candidate beams satisfy the AoA separation threshold. For example, the method may include identifying a first AoA for a first candidate beam from the plurality of directional candidate beams, and identifying a second AoA for a second candidate beam from the plurality of directional candidate beams. The method may further include selecting, at the UE, the first candidate beam and the second candidate beam based on a determination that the first AoA and the second AoA satisfies the AoA separation threshold. In some examples, the AoA separation component <NUM> may perform the beam measurements associated with AoA separation.

In another example, performing the beam measurements may include determining whether the one or more candidate beams satisfy the RSRP correlation threshold. In such instance, the UE may identify a first RSRP for a first candidate beam from the plurality of directional candidate beams during a first time period, and identify a second RSRP for the first candidate beam during a second time period. The UE may further calculate RSRP correlation between the first RSRP and the second RSRP, and select, at the UE, the first candidate beam based on a determination that the RSRP correlation is less than the RSRP-correlation threshold. In some examples, selecting the first candidate beam may include reporting the beam ID associated with the first candidate beam to the base station such that the base station may configure the TCI states. In some examples, the RSRP correlation component <NUM> may perform the beam measurements associated with the RSRP correlation for the plurality of candidate beams.

In yet another example, performing the beam measurements may include determining whether the one or more candidate beams satisfy the spatial correlation threshold. In such instance, the method may include determining whether a spatial correlation between a first candidate beam and a second candidate beam from the plurality of directional candidate beams satisfies the spatial-correlation threshold. The method may further include selecting, at the UE, the first candidate beam and the second candidate beam based on a determination that spatial correlation is less than the spatial-correlation threshold.

In some examples, performing the beam measurements may include performing a first beam measurement for one or more uplink beams, performing a second beam measurement for one or more downlink beams, and generating the beam diversity response that reports the first beam measurement for the one or more uplink beams separate from the second beam measurement for the one or more downlink beams. Specifically, in some examples, the UE may report beams for diversity as a separate report for uplink beams and a separate report for downlink beams. For instance, the UE may report {SSB <NUM>, <NUM>} for DL beams, while {SSB <NUM>, SSB <NUM>} for UL beams. Thus, in cases where downlink beam may be considered good (e.g., satisfies channel condition threshold), but the uplink beam derived from downlink may not be good (e.g., due to maximum power emission (MPE ), the base station may request the UE to provide reports associated with a set of diverse beams for downlink beams which the base station can use for transmitting PDCCH, and a separate set of UE uplink beams for receiving PUCCH.

In some examples, the spatial correlation component <NUM> may perform the beam measurements associated with determining whether one or more candidate beams satisfy spatial correlation.

At block <NUM>, the method <NUM> may optionally include selecting, at the UE, one or more beams from the plurality of directional candidate beams transmitted by the base station that satisfy a beam diversity threshold. For example, in an aspect, aspects of block <NUM> may also be performed by beam diversity selection component <NUM> described with reference to <FIG>.

At block <NUM>, the method <NUM> may include transmitting a beam diversity response based on the beam measurements. In some examples, the beam diversity response may include beam indices of the one or more beams selected from the plurality of directional candidate beams. In other examples, instead of beam indices, the beam diversity response may include a beam measurement report associated with one or more of the RSRP correlation, AoA separation, or the spatial correlation for the plurality of directional candidate beams. As such, the base station <NUM> may group one or more beams based on the beam measurement report. Aspects of block <NUM> may be performed by transceiver <NUM> in conjunction measurement reporting component <NUM> with described with reference to <FIG>.

At block <NUM>, the method <NUM> may optionally include receiving identification of a plurality of TCI states, wherein the plurality are uncorrelated beams each selected from different groupings of correlated beams based on the beam diversity response. Aspects of block <NUM> may be performed by transceiver <NUM> described with reference to <FIG>.

At block <NUM>, the method may include communicating based on the identified plurality of TCI states. Aspects of block <NUM> may be performed by transceiver <NUM> in conjunction measurement reporting component <NUM> with described with reference to <FIG>.

<FIG> illustrates a hardware components and subcomponents of a device that may be a base station <NUM> for implementing one or more methods (e.g., method <NUM>) described herein in accordance with various aspects of the present disclosure. For example, one example of an implementation of the base station <NUM> may include a variety of components, some of which have already been described above, but including components such as one or more processors <NUM>, memory <NUM> and transceiver <NUM> in communication via one or more buses <NUM>, which may operate in conjunction with the communication management component <NUM> to perform functions described herein related to including one or more methods (e.g., <NUM>) of the present disclosure.

In some examples, the communication management component <NUM> may include a beam grouping component <NUM> may that may group one or more beams into one or more TCI states based on the beam indices or beam measurement reports received from the UE <NUM>. In the instance where the base station <NUM> may receive the beam measurement reports in lieu of beam indices selected by the UE <NUM>, the beam grouping component <NUM> may employ one or more RSRP-correlation component <NUM>, AoA separation component <NUM>, and/or spatial correlation component <NUM> to group one or more beams based on RSRP correlation measurements, AoA separation measurements, and/or spatial correlation measurements that may be received in the beam measurement reports from the UE <NUM>.

The one or more processors <NUM>, modem <NUM>, memory <NUM>, transceiver <NUM>, RF front end <NUM> and one or more antennas <NUM>, may be configured to support voice and/or data calls (simultaneously or non-simultaneously) in one or more radio access technologies. In an aspect, the one or more processors <NUM> can include a modem <NUM> that uses one or more modem processors. The various functions related to communication management component <NUM> may be included in modem <NUM> and/or processors <NUM> and, in an aspect, can be executed by a single processor, while in other aspects, different ones of the functions may be executed by a combination of two or more different processors. For example, in an aspect, the one or more processors <NUM> may include any one or any combination of a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receiver processor, or a transceiver processor associated with transceiver <NUM>. In other aspects, some of the features of the one or more processors <NUM> and/or modem <NUM> associated with communication management component <NUM> may be performed by transceiver <NUM>.

The memory <NUM> may be configured to store data used herein and/or local versions of application(s) <NUM> or communication management component <NUM> and/or one or more of its subcomponents being executed by at least one processor <NUM>. The memory <NUM> can include any type of computer-readable medium usable by a computer or at least one processor <NUM>, such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, the memory <NUM> may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes defining communication management component <NUM> and/or one or more of its subcomponents, and/or data associated therewith, when the UE <NUM> is operating at least one processor <NUM> to execute communication management component <NUM> and/or one or more of its subcomponents.

As such, the transceiver <NUM> may be configured to transmit and receive wireless signals through one or more antennas <NUM> via the RF front end <NUM>. In an aspect, the transceiver <NUM> may be tuned to operate at specified frequencies such that transmitting device can communicate with, for example, one or more UEs <NUM> or one or more cells associated with one or more base stations <NUM>. In an aspect, for example, the modem <NUM> can configure the transceiver <NUM> to operate at a specified frequency and power level based on the configuration of the transmitting device and the communication protocol used by the modem <NUM>.

<FIG> is a flowchart of an example method <NUM> for wireless communications in accordance with aspects of the present disclosure. The method <NUM> may be performed using the base station <NUM>. Although the method <NUM> is described below with respect to the elements of the base station <NUM>, other components may be used to implement one or more of the steps described herein.

At block <NUM>, the method <NUM> may include transmitting a beam diversity request to a UE, wherein the beam diversity request is associated with a plurality of directional candidate beams transmitted by the base station towards the UE. In some examples, the beam diversity request from the base station includes information associated with beam diversity threshold. In some examples, beam diversity threshold may comprise of one or more of RSRP-correlation threshold, AoA separation threshold, or spatial-correlation threshold that the beam measurements must satisfy to be included in the beam diversity response. Aspects of block <NUM> may be performed by transceiver <NUM> described with reference to <FIG>.

At block <NUM>, the method <NUM> may include receiving, from the UE, a beam diversity response based on the beam diversity request. In some examples, the beam diversity response may include beam indices of the one or more beams selected from the plurality of directional candidate beams. In another example, the beam diversity response includes a beam measurement report associated with one or more of the RSRP correlation, AoA separation, or the spatial correlation for the plurality of directional candidate beams. Aspects of block <NUM> may also be performed by transceiver <NUM> described with reference to <FIG>.

At block <NUM>, the method <NUM> may include grouping one or more beams from the plurality of directional candidate beams into a plurality of TCI states, wherein the one or more beams are selected based on beam characteristic correlation information for the plurality of directional candidate beams. In some examples, beam characteristic correlation information for the plurality of directional candidate beams may include on one or more of RSRP correlation, AoA separation, or spatial correlation for the plurality of directional candidate beams. Aspects of block <NUM> may also be performed by beam grouping component <NUM>, and more particularly one or more of RSRP - correlation component <NUM>, AoA separation component <NUM>, and/or spatial correlation component <NUM> described with reference to <FIG>.

At block <NUM>, the method <NUM> may optionally include transmitting identification of a plurality of TCI states, wherein the plurality are uncorrelated beams each selected from different groupings of correlated beams based on the beam diversity response. Aspects of block <NUM> may be performed by transceiver <NUM> described with reference to <FIG>.

At block <NUM>, the method may include communicating based on the identified plurality of TCI states. Aspects of block <NUM> may be performed by transceiver <NUM> with described with reference to <FIG>.

Claim 1:
A method (<NUM>) for wireless communications implemented by a user equipment, UE, (<NUM>) comprising:
receiving (<NUM>), at the UE, a beam diversity request (<NUM>) from a base station (<NUM>);
performing (<NUM>) beam measurements for a plurality of directional candidate beams (<NUM>-a, <NUM>-b, <NUM>-c) transmitted by the base station towards the UE based in part on the beam diversity request, wherein the beam measurements comprise beam characteristic correlation information for the plurality of directional candidate beams; and
transmitting (<NUM>) a beam diversity response (<NUM>) based on the beam measurements;
wherein performing the beam measurements for the plurality of directional candidate beams transmitted by the base station towards the UE is characterized by comprising:
identifying a first reference signals received power, RSRP, for each candidate beam from the plurality of directional candidate beams during a first time period;
identifying a second RSRP for each candidate beam during a second time period;
calculating RSRP correlation as the difference between the first RSRP and the second RSRP; and
selecting, at the UE, each respective candidate beam based on a determination that the RSRP correlation is less than a RSRP-correlation threshold.