Beam quality metric based on Gram matrix

Abstract

This application is concerned with selecting a transmit-receive beam pair at a first apparatus (e.g. a UE) based on a beam quality value. The first apparatus determines the quality value for each of a

Description

FIELD

[0001] Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, apparatuses and computer readable storage medium for beam quality determination based on Gram matrix of a Multiple Input Multiple Output (MIMO) Channel. BACKGROUND

[0002] Conventionally, in beam management procedures, the network may configure / activate frequent periodic or semi-persistent beam reporting or trigger frequent aperiodic beam reporting to timely acquire the best / preferred beam for data / control transmissions. On the other hand, given that use equipment (UE) has better and more-timely knowledge of beam quality changes, UE-initiated beam reporting procedures are introduced to provided more timely beam reports with reduced reporting overhead. SUMMARY

[0003] In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: determine a channel matrix based on at least one reference signal, the at least one reference signal being transmitted using at least one transmission beam among a set of transmission beams by a second apparatus and received using at least one reception beam among a set of reception beams by the first apparatus; determine a Gram matrix associated with a channel capacity based on the channel matrix; and determine a beam quality for at least one of the at least one transmission beam or the at least one reception beam based on the Gram matrix.

[0004] In a second aspect of the present disclosure, there is provided a method. The method comprises: determining a channel matrix based on at least one reference signal, the at least one reference signal being transmitted using at least one transmission beam among a set of transmission beams by a second apparatus and received using at least one reception beam among a set of reception beams by the first apparatus; determining a Gram matrix associated with a channel capacity based on the channel matrix; and determining a beam quality for at least one of the at least one transmission beam or the at least one reception beam based on the Gram matrix.

[0005] In a third aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for determining a channel matrix based on at least one reference signal, the at least one reference signal being transmitted using at least one transmission beam among a set of transmission beams by a second apparatus and received using at least one reception beam among a set of reception beams by the first apparatus; means for determining a Gram matrix associated with a channel capacity based on the channel matrix; and means for determining a beam quality for at least one of the at least one transmission beam or the at least one reception beam based on the Gram matrix.

[0006] In a fourth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the second aspect.

[0007] It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0009] FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0010] FIGS. 2A to 2C illustrate schematic diagrams of impacts of different transmission (TX) beams on channel matrix, respectively;

[0011] FIG. 3 illustrates a signaling flow for determining a beam quality based on Gram matrix according to some example embodiments of the present disclosure;

[0012] FIG. 4 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

[0013] FIG. 5 illustrates a signaling flow for transmission of a beam report according to some example embodiments of the present disclosure;

[0014] FIG. 6 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

[0015] FIG. 7 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

[0016] FIG. 8 illustrates a signaling flow for transmission of a beam report according to some example embodiments of the present disclosure;

[0017] FIG. 9 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

[0018] FIG. 10 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

[0019] FIG. 11 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0020] FIG. 12 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0021] Throughout the drawings, the same or similar reference numerals represent the same or similar element. DETAILED DESCRIPTION

[0022] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0023] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0024] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0025] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0026] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0027] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0029] As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0030] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) 5 accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0031] As used herein, the term “communication network” refers to a network following 10 any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation 15 communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0032] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

[0033] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0034] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0035] FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure can be implemented. In the communication environment 100, a plurality of communication devices, including a first apparatus 110 and a second apparatus 120 can communicate with each other.

[0036] In the example of FIG. 1, the second apparatus 120 has a certain coverage range, which may be called as a serving area or a source cell. The first apparatus 110 is located in the cell managed by the second apparatus 120. In the communication environment 100, the second apparatus 120 may communicate data and control information with the first apparatus 110.

[0037] In some example embodiments, if the first apparatus 110 is a terminal device and the second apparatus 120 is a network device, a link from the second apparatus 120 to the first apparatus 110 is referred to as a downlink (DL), while a link from the first apparatus 110 to the second apparatus 120 is referred to as an uplink (UL). In DL, the second apparatus 120 is a transmitting (TX) device (or a transmitter) and the first apparatus 110 is a receiving (RX) device (or a receiver). In UL, the first apparatus 110 is a TX device (or a transmitter) and the second apparatus 120 is a RX device (or a receiver).

[0038] It is to be understood that the number of apparatuses and their connections shown in FIG. 1 are only for the purpose of illustration without suggesting any limitation. The communication environment 100 may include any suitable number of apparatuses configured to implementing example embodiments of the present disclosure.

[0039] In the following, for purpose of illustration, some example embodiments are described with the first apparatus 110 operating as a terminal device and the second apparatus 120 operating as a network device. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other device.

[0040] Communications in the communication environment 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G), the sixth generation (6G), and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0041] In 3GPP specs, one finds metrics such as Layer 1 reference signal received power (Ll-RSRP) or Layer 1 interference plus noise ratio (Ll-SINR) for determining beam quality. However, in some scenarios (e.g., environments with rich scattering, many reflectors, etc.), selecting a beam based on such metrics may be suboptimal, e.g., it may not allow fully exploiting the MIMO channel capacity via spatial multiplexing.

[0042] FIGS. 2A to 2C illustrate schematic diagrams of impacts of different TX beams (bA, bn, be) on channel matrix, respectively. Specifically, FIGS. 2A to 2C illustrate examples of how beam selection in Frequency Range 2 (FR2) may impact the ability to perform spatial multiplexing. In the examples, the physical radio channel between TRP and UE has three main signal propagation paths (m, 712,113), including a line of sight (LOS) path (ni) and two additional Non-Line of Sight (NLOS) paths (712, 713) via corresponding reflectors.

[0043] In FIG. 2A, a narrow, high-gain TX beam (bA) is selected, focusing most of the TX power towards the LOS path (711). Such beam selection may be motivated by a desire to maximize Ll-RSRP and / or Ll-SINR. For example, the network may sweep a set of Channel State Information - Reference Signals (CSLRSs) using a set of narrow, high-gain TX beams, and the UE may report bA as the TX beam with largest Ll-RSRP.

[0044] In FIG. 2B, a wider TX beam (bn) is selected, with some TX power radiated towards the LOS path (711) and some TX power radiated towards a nearby reflector (712). As a result of the lower beamforming gain (compared to bA), the wider TX beam (bn) may not maximize Ll-RSRP. However, a spatial multiplexing gain may be achieved under certain conditions, potentially resulting in a higher channel capacity. In this case, the reflector is relatively close to the TRP, thus the angular separation between the LOS path (711) and the reflected path (712), as seen from the UE, is small. As a result, the received signals (e.g., on each polarization) may be subject to correlated fading, making spatial multiplexing challenging.

[0045] In FIG. 2C, another wide TX beam (be) is selected, with some TX power radiated towards the LOS path (tti) and some TX power radiated towards a remote reflector (713), e.g., located in the proximity of the UE. In this case, the angular separation between the LOS path (711) and the reflected path (713), as seen from the UE, is larger. As a result, the received signals (e.g., on each polarization) are less likely to be subject to correlated fading. Thus, selecting this wider TX beam (be) instead of the narrow TX beam (b \) may be beneficial, e.g., if the spatial multiplexing gain is greater than the loss due to a lower beamforming gain.

[0046] This example illustrates that beam selection in environments with rich scattering may be enhanced by carefully considering the tradeoff between maximizing RSRP / SNR / SINR (e.g., by using narrower beams) and exploiting the rich scattering offered by the radio channel for spatial multiplexing (e.g., by using wider beams).

[0047] As shown in right sides of FIGS. 2A to 2C, different TX beams (Ba, bn, be) may impact or alter the nrxnt channel matrix (Ha, Hb, He) observed by the UE in different ways (here, to draw simple examples we assume nt = nr = 2 antenna ports). For example, a narrow TX beam (bA) may result in a rank-1 channel matrix (Ha) (thus preventing spatial multiplexing), whereas a wider TX beam (bs, be) may result in a rank-2 channel matrix (Hb, He). A higher rank may allow for a larger number of transmission layers to be spatially multiplexed. However, the rank alone may not be sufficient to determine whether a particular TX beam is more desirable than others. For example, TX beams bs and be may both result in a rank-2 channel matrix (i.e., rank(HB) = rank(Hc) = 2). However, the column vectors (hi.B, h2.B) of Hb may be at a smaller angle to each other (i.e., closer to being parallel, or linearly dependent) than the column vectors (hi,c, h2,c) of He. As a result, it may be desirable to select TX beam be rather than TX beam bB for multiplexing two transmission layers, possibly achieving a higher throughput compared to TX beam bA corresponding to the largest Ll-RSRP.

[0048] An nr- nt channel matrix H having full rank n = min(nt, nr) (e.g., Hb, He, but not Ha) may be viewed as having an associated n-dimensional parallelotope (e g., a 2D parallelogram P(Hb), P(Hc) in the example of Figure 1), whose n-dimensional volume depends on the n linearly independent column vectors of H (if nt <nr), or Hn (if nt >nr). The larger the magnitude of the vectors and their angular separation, the larger the volume of the parallelotope. This motivates selecting a beam (be) that maximizes the volume of the parallelotope (P(Hc)) associated with the resulting channel matrix. Such a beam may maximize the capacity of the MIMO channel.

[0049] The channel capacity C (bit / s / Hz), in the absence of CSI at the transmitter, may be written as C = log2(det(Inr + qHH^)) = log2(det(Int + qH^H)) (1) where q >0 is some non-negative scalar, lnr and Int are identity matrices, and HH and HhH are Gram matrices. Note that this constitutes a lower bound with respect to the channel capacity that may be achieved when CSI is available at the transmitter (i.e., via CSI reports from the UE).

[0050] In the special case nt = nr = 2, we can use the identity det(A + B) = det(A) + det(B) + tr(A) tr(B) - tr(AB) (2) to obtain det(Inr + qHH77) = det(Inr) + det(qHH77) + tr(Lr) tr(qHH^) - trQnrqHH77) (3) which simplifies to det(Inr + q H H") = 1 + q2 det(HH") + q tr(HHH) (4)

[0051] Thus, when nt = nr = 2, the channel capacity (C) may be maximized by maximizing the sum q2 det(HH") + q tr(HH") (5)

[0052] If tr(HH77) « q det(HH77), this may be achieved by maximizing the Gram determinant det(HH77). This illustrates that, under certain conditions (i.e., high SNR and not too small Gram determinant), the Gram determinant may be a good approximation of the channel capacity.

[0053] In the special (rank-1) cases of Single-Input Single-Output (SISO) (nt = nr = 1), Multi-Input Single-Output (MISO) (nt >1, nr = 1) and Single-Input Multiple-Output (SIMO) (nt = 1, nr >1), the Gram matrices H U (when nt = 1 <nr) and HH77 (when nt >1 = nr) are scalar (1><1) and the following holds for any two channel matrices (Hi, H2) of the same size (nr I or lxnt): when nt = 1 <nr, if Hi ll 1 >II2 H2. then C(Hi) >C(Hz), and when nt >1 = nr, if H1H177 >H2H277, then C(Hi) >C(H2), where C(Hin) denotes the above-defined channel capacity C corresponding to channel matrix Hm. Thus, in such cases, maximizing the Gram determinant (det(H"H) = HH and de^HH77) = HH77, respectively) results in maximizing the SNR, and consequently the channel capacity.

[0054] Embodiments of the present disclosure provide a new beam quality metric (Qm) for beam selection and / or beam reporting among a set of beams (bm, m = 1, ... , M), that can be beneficial in environments with rich scattering (e.g., a factory floor or dense urban areas). The new metric (Qm) identifies how “good” or effective such a rank is in eventually maximizing the throughput, e.g., distinguishing the scenarios in FIG. 2B and FIG. 2C, by taking into account the “volume” of the radio channel Hm (determined by the Gram matrix H Hm orHHm77) resulting from applying a particular beam (bm). In one example, the metric (Qm) is based on the channel capacity in the absence of CSI at the TX side (which constitutes a lower bound of the capacity when CSI is available at the TX side).

[0055] As discussed above, conventional beam quality metrics (e.g., Ll-RSRP, Li SINR) for beam selection and / or beam reporting in FR2 may be suboptimal in radio environments that allow for spatial multiplexing to be exploited to increase channel capacity. The proposed metric of the beam quality addresses this limitation by considering how a particular beam impacts or alters the “volume” of the channel, i.e., the ability to spatially multiplex multiple data streams along linearly independent directions of the resulting channel.

[0056] Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0057] FIG. 3 illustrates a signaling flow 300 for determining a beam quality based on Gram matrix according to some example embodiments of the present disclosure. For the purposes of discussion, the signaling flow 300 will be discussed with reference to FIG. 1, for example, by using the first apparatus 110 and the second apparatus 120. In some embodiments the first apparatus 110 may be discussed with a terminal device, e.g., a UE, and the second apparatus 120 may be discussed with a network device, e.g., a gNB.

[0058] In the signaling flow 300, the first apparatus 110 determines (315) a channel matrix based on at least one reference signal, for example, CSI-RS. The at least one reference signal may be transmitted using at least one transmission beam among a set of transmission beams by a second apparatus and received using at least one reception beam among a set of reception beams by the first apparatus 110.

[0059] The channel matrix may be associated with several factors, which may include, but not limited to, a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams, and / or the like.

[0060] In some example embodiments, for each TX beam in a set of TX beams (bm, m = 1, ... , M) applied by the second apparatus 120, e.g., a gNB (which may be referred to as the network), the first apparatus 110, e.g., a UE may determine a corresponding channel matrix (Hm, m = 1, ... , M). This can be based on existing channel sounding and channel estimation methods, e.g., relying on (periodic, semi-persistent and / or aperiodic) multiport CSI-RS(s). For example, the network may transmit periodically on each TX beam (bm) a (wideband) 2-port CSI-RS (RSm), with each of nt = 2 TX antenna ports corresponding to one polarization of a cross-polarized antenna panel at the network side. The UE may perform measurements on the transmitted CSI-RS(s) on nr = 2 RX antenna ports, each corresponding to one polarization of a cross-polarized antenna panel at the UE side. Based on the measurements, the UE may estimate the nr nt = 2x2 channel matrix Hm for each TX beam bm.

[0061] In some embodiments, the UE may perform the measurements using different RX beams from a set of RX beams (ci, 1 = 1, ... , L) and determine a channel matrix Hm,i for each TX / RX beam pair (bm, ci) of several possible TX / RX beam pairs. For example, this may be enabled by the network transmitting CSI-RS with repetition enabled (repetition = ‘ON’). In this case, the term “beam quality” used herein may be understood as the quality of a particular TX / RX beam pair.

[0062] In some embodiments, the network may be able to use more than one TX beam simultaneously for transmission to a same UE (e.g., multi-TRP operation). For example, the network may transmit using 2 TX beams simultaneously, each with 2 polarizations, thus allowing up to 4 spatially multiplexed transmission layers. In this case, the UE (e.g., multi-panel, multi-RX) may perform measurements to determine a nrxnt = 4x4 channel matrix Hmi,m2 for each TX beam pair (bmi, bm2) of several possible TX beam pairs (or more generally TX beam “groups”, as in “Group Based Beam Reporting”, GBBR). In this case, the term “beam quality” used herein may be understood as the quality of a particular TX beam pair (group). Moreover, the UE may perform such measurements using different RX beam pairs (more generally, RX beam “groups”), and determine a nrxnt = 4x4 channel matrix Hmi,m2,11,12 for each of several possible combinations of a TX beam pair (bmi, bm2) and a RX beam pair (cu, C12). In this case, the term “beam quality” used herein may be understood as the quality of a particular combination of a TX beam pair (group) and a RX beam pair (group).

[0063] In some example embodiments, the number of TX antenna ports and / or RX antenna ports per TX beam may be larger than 2.

[0064] Based on the channel matrix, the first apparatus 110 determines (320) a Gram matrix associated with a channel capacity.

[0065] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception. Alternatively, or in addition, the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0066] For example, in the case where the nrxnt channel matrix Hm has full rank r = min(nt, nr), the Gram matrix may be determined as HmHHm if nt <nr, and determined as HmHmHz / nt>nr,

[0067] On the basis of the Gram matrix, the first apparatus 110 determines (325) the beam quality for the at least one transmission beam and / or the at least one reception beam. The beam quality may be determined in a variety of ways. In some example embodiments, the first apparatus 110 may further determine the beam quality based on a determinant of the Gram matrix.

[0068] In some example implementations, based on the channel matrix Hm for each TX beam bm, the first apparatus 110, e.g., the UE, may determine a beam quality Qm by calculating a determinant. The same applies to the cases described above of a channel matrix Hm,i for a TX / RX beam pair (with quality Qm.i), a channel matrix Hmi,m2 for a TX beam pair (group) (with quality Qmi,m2), or a channel matrix Hmi,m2,11,12 for a combination of a TX beam pair (group) and a RX beam pair (group) (with quality Qmi,m2,n,i2). It is to be understood that, although this example focuses on the case of a channel matrix Hm corresponding to a TX beam bm, what follows applies equally well to the other cases described above.

[0069] In some cases, when the nrxnt channel matrix Hm has full rank r = min(nt, nr), the beam quality Qm may be calculated: when nt <nr, based on the Gram determinant Tm = det(Htn / / Hm), and when nt >nr, based on the Gram determinant T’m = detlHmHm"), corresponding to the (squared) r-dimensional volume of the parallelotope, P(Hm) or P(Hmff), generated by the r (linearly independent) column vectors of Hm or HmH, respectively.

[0070] Alternatively, in some example embodiments, when determining (325) the beam quality, the first apparatus 110 may further determine a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix, and determine the beam quality based on a determinant of the sum. The scaling factor may be determined based on a measured value of a noise and / or interference power.

[0071] Specifically, the beam quality Qm may be calculated based on a determinant of a sum of an identity matrix plus a scaled Gram matrix, e.g., det(Int + qHm^Hm) or det(Inr + wherein the scaling factor (q) depends on a noise power. For example, the scaling factor (q) may be derived from a measured Ll-SINR.

[0072] In other cases, either when the channel matrix Hm has full rank (i.e., r = min(nt, nr)) or when the channel matrix Hm is rank-deficient (i.e., r <min(nt, nr)), the beam quality Qm may be calculated as the product of the squares of the non-zero singular values of Hm. As an example, if oi, 02, ... , Or are the non-zero singular values of Hm, then Qm = 01¾2 ... Or2. Note that the squared singular values (ai2) of Hm are equal to the eigenvalues (Xi) of the Gram matrix IVHm (nt <nr) or (nt >nr).

[0073] In other cases, either when the channel matrix Hm has full rank (i.e., r = min(nt, nr)) or when the channel matrix Hm is rank-deficient (i.e., r <min(nt, nr)), the beam quality Qm may be calculated as Qm = (l+qoi2)(l+qo22) ... (l+qoi2), where 01, 02, ... , Or are the non-zero singular values of Hm, and the scaling factor (q) depends on a noise power.

[0074] In some example embodiments, the first apparatus 110 may further transmit (330) a beam report to the second apparatus based on the determined beam quality. The beam report may indicate the beam quality, a beam corresponding to the beam quality and or other information. In an example implementation, the beam report may include, for example, the value of the beam quality, an index of the corresponding beam, and / or the like.

[0075] In an example, after determining the beam quality Qm for each TX beam bm (m = 1, ... , M), the first apparatus 110, e.g., the UE, may transmit a beam report to the network based on the determined beam qualities. The UE may be configured to do so. In some cases, the UE may be configured to indicate a set of best beams (e.g., N best beams). The beam report may also include the corresponding beam qualities.

[0076] In addition to the above, in some example embodiments, before the determination (315) of the channel matrix, the first apparatus 110 may first receive (310), from the second apparatus, a configuration indicating that a beam report is to be transmitted based on the beam quality. The configuration may have various forms, for example, but not limited to, a CSI report configuration. With the configuration, the first apparatus 110 may be aware that the determined beam quality needs to be transmitted via the beam report and transmit (330) the beam report accordingly.

[0077] The configuration may be transmitted in various ways, for example, via system information, a radio resource control (RRC)signaling, medium access control control element (MAC CE), downlink control information (DCI), and / or the like.

[0078] For example, the network may use a CSI report configuration (e.g., CSI-ReportConfig) to configure the UE to transmit beam reports based on the beam quality metric (Qm) proposed herein, alternatively or additionally to other quality metric(s) (e.g., Ll-RSRP, Ll-SINR).

[0079] In view of the above, by considering how a particular beam impacts or alters the channel capacity, i.e., the ability to spatially multiplex multiple data streams along linearly independent directions of the resulting channel, the proposed metric of the beam quality addresses limitations in conventional radio environments.

[0080] FIG. 4 shows a flowchart of an example method 400 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 400 will be described from the perspective of the first apparatus 110 in FIG. 1.

[0081] At block 410, the first apparatus 110 determines a channel matrix based on at least one reference signal, the at least one reference signal being transmitted using at least one transmission beam among a set of transmission beams by a second apparatus and received using at least one reception beam among a set of reception beams by the first apparatus.

[0082] At block 420, the first apparatus 110 determines a Gram matrix associated with a channel capacity based on the channel matrix.

[0083] At block 430, the first apparatus 110 determines a beam quality for at least one of the at least one transmission beam or the at least one reception beam based on the Gram matrix.

[0084] In some example embodiments, the first apparatus 110 may further determine the beam quality based on a determinant of the Gram matrix.

[0085] In some example embodiments, the first apparatus 110 may further determine a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix, and determine the beam quality based on a determinant of the sum.

[0086] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, and the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0087] In some example embodiments, the scaling factor is determined based on a measured value of a noise and / or interference power.

[0088] In some example embodiments, the channel matrix is associated with at least one of: a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, or a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

[0089] In some example embodiments, the first apparatus 110 may further transmit a beam report to the second apparatus based on the determined beam quality.

[0090] In some example embodiments, the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

[0091] In some example embodiments, the first apparatus 110 may further receive, from the second apparatus, a configuration indicating that a beam report is to be transmitted based on the beam quality.

[0092] In some example embodiments, the at least one reference signal comprises a CSI-RS, and the configuration comprises a CSI report configuration.

[0093] In some example embodiments, the first apparatus 110 comprises a terminal device, and the second apparatus 120 comprises a network device.

[0094] FIG. 5 illustrates a signaling flow 500 for transmission of a beam report according to some example embodiments of the present disclosure. For the purposes of discussion, the signaling flow 500 will be discussed with reference to FIG. 1, for example, by using the first apparatus 110 and the second apparatus 120. In some embodiments the first apparatus 110 may be discussed with a terminal device, e.g., a UE, and the second apparatus 120 may be discussed with a network device, e.g., a gNB.

[0095] In the signaling flow 500, the first apparatus 110 determines (505) a beam quality based on a Gram matrix associated with a channel capacity. The Gram matrix is determined based on a channel matrix associated with at least one transmission beam among a set of transmission beams of the second apparatus 120 and at least one reception beam among a set of reception beams of the first apparatus 110.

[0096] In some example embodiments, the first apparatus 110 may determine the channel matrix based on at least one reference signal, for example, CSI-RS. The at least one reference signal may be transmitted using at least one transmission beam among a set of transmission beams by a second apparatus and received using at least one reception beam among a set of reception beams by the first apparatus 110.

[0097] The channel matrix may be associated with several factors, which may include, but not limited to, a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams, and / or the like.

[0098] In some example embodiments, for each TX beam in a set of TX beams (bm, m = 1, ... , M) applied by the network, the first apparatus 110, e.g., a UE may determine a corresponding channel matrix (Hm, m = 1, ... , M). This can be based on existing channel sounding and channel estimation methods, e.g., relying on (periodic, semi-persistent and / or aperiodic) multi-port CSI-RS(s). For example, the network may transmit periodically on each TX beam (bm) a (wideband) 2-port CSI-RS (RSm), with each of nt = 2 TX antenna ports corresponding to one polarization of a cross-polarized antenna panel at the network side. The UE may perform measurements on the transmitted CSI-RS(s) on nr = 2 RX antenna ports, each corresponding to one polarization of a cross-polarized antenna panel at the UE side. Based on the measurements, the UE may estimate the nrxnt = 2><2 channel matrix Hm for each TX beam bm.

[0099] In some embodiments, the UE may perform the measurements using different RX beams from a set of RX beams (ci, 1 = 1, ... , L) and determine a channel matrix Hm.i for each TX / RX beam pair (bm, ci) of several possible TX / RX beam pairs. For example, this may be enabled by the network transmitting CSI-RS with repetition enabled (repetition = ‘ON’). In this case, the term “beam quality” used herein may be understood as the quality of a particular TX / RX beam pair.

[0100] In some embodiments, the second apparatus 120, e g., a gNB which may be referred to as the network, may be able to use more than one TX beam simultaneously for transmission to a same UE (e.g., multi-TRP operation). For example, the network may transmit using 2 TX beams simultaneously, each with 2 polarizations, thus allowing up to 4 spatially multiplexed transmission layers. In this case, the UE (e.g., multi-panel, multi-RX) may perform measurements to determine a nrxnt = 4 4 channel matrix Hmi.m2 for each TX beam pair (bmi, bm2) of several possible TX beam pairs (or more generally TX beam “groups”, as in “Group Based Beam Reporting”, GBBR). In this case, the term “beam quality” used herein may be understood as the quality of a particular TX beam pair (group). Moreover, the UE may perform such measurements using different RX beam pairs (more generally, RX beam “groups”), and determine a nrxnt = 4x4 channel matrix Hmi.m2.ii.i2 for each of several possible combinations of a TX beam pair (bmi, bm2) and a RX beam pair (cn, C12). In this case, the term “beam quality” used herein may be understood as the quality of a particular combination of a TX beam pair (group) and a RX beam pair (group).

[0101] In some example embodiments, the number of TX antenna ports and / or RX antenna ports per TX beam may be larger than 2.

[0102] Based on the channel matrix, the first apparatus 110 may determine the Gram matrix associated with a channel capacity. In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception. Alternatively, or in addition, the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0103] For example, in the case where the nrxnt channel matrix Hm has full rank r = min(nt, nr), the Gram matrix may be determined as HmHHm if nt <nr, and determined as H 4L if nt >nr,

[0104] On the basis of the Gram matrix, the first apparatus 110 may determine the beam quality for the at least one transmission beam and / or the at least one reception beam. The beam quality may be determined in a variety of ways. In some example embodiments, the first apparatus 110 may further determine the beam quality based on a determinant of the Gram matrix.

[0105] In some example implementations, based on the channel matrix Hm for each TX beam bm, the first apparatus 110, e.g., the UE, may determine a beam quality Qm by calculating a determinant. The same applies to the cases described above of a channel matrix Hm,i for a TX / RX beam pair (with quality Qm,i), a channel matrix Hmi,m2 for a TX beam pair (group) (with quality Qmi,m2), or a channel matrix Hmi.m2,11,12 for a combination of a TX beam pair (group) and a RX beam pair (group) (with quality Qmi,m2,u,i2). It is to be understood that, although this example focuses on the case of a channel matrix Hm corresponding to a TX beam bm, what follows applies equally well to the other cases described above.

[0106] In some cases, when the nrxnt channel matrix Hm has full rank r = min(nt, nr), the beam quality Qm may be calculated: when nt <nr, based on the Gram determinant Tm = det(Hm / / Hm), and when nt >nr, based on the Gram determinant T’m = det(HmHm / f), corresponding to the (squared) r-dimensional volume of the parallelotope, P(Hm) or P(Hmff), generated by the r (linearly independent) column vectors of Hm or Ht / , respectively.

[0107] Alternatively, in some example embodiments, when determining the beam quality, the first apparatus 110 may further determine a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix, and determine the beam quality based on a determinant of the sum. The scaling factor may be determined based on a measured value of a noise and / or interference power.

[0108] Specifically, the beam quality Qm may be calculated based on a determinant of a sum of an identity matrix plus a scaled Gram matrix, e.g., det(Int + qHm^Hm) or det(Inr + qHmHm"), wherein the scaling factor (q) depends on a noise power. For example, the scaling factor (q) may be derived from a measured Ll-SINR.

[0109] In other cases, either when the channel matrix Hm has full rank (i.e., r = min(nt, nr)) or when the channel matrix Hm is rank-deficient (i.e., r <min(nt, nr)), the beam quality Qm may be calculated as the product of the squares of the non-zero singular values of Hm. As an example, if gi, 02, ... , Gr are the non-zero singular values of Hm, then Qm = gi2G22 ... Gr2. Note that the squared singular values (c,2) of Hm are equal to the eigenvalues (Xi) of the Gram matrix R / Hm (nt <nr) or HmHm" (nt >nr).

[0110] In other cases, either when the channel matrix Hm has full rank (i.e., r = min(nt, nr)) or when the channel matrix Hm is rank-deficient (i.e., r <min(nt, nr)), the beam quality Qm may be calculated as Qm = (l+qGi2)(l+qo22) ... (l+qGr2), where gi, G2, ... , Gr are the non-zero singular values of Hm, and the scaling factor (q) depends on a noise power.

[0111] Still referring to FIG. 5, based on the determined beam quality, the first apparatus 110 transmits (510) a beam report to the second apparatus 120. The second apparatus 120 receives (515) the beam report associated with the beam quality from a first apparatus 110.

[0112] The beam report may indicate the beam quality, a beam corresponding to the beam quality and or other information. The beam report may include, for example, the value of the beam quality, an index of the corresponding beam, and / or the like.

[0113] In an example implementation, after determining the beam quality Qm for each TX beam bm (m = 1, ... , M), the first apparatus 110, e.g., the UE, may transmit a beam report to the second apparatus 120, e.g., the network, based on the determined beam qualities. The UE may be configured to do so. In some cases, the UE may be configured to indicate a set of best beams (e.g., N best beams). The beam report may also include the corresponding beam qualities.

[0114] In addition to the above, in some example embodiments, before the determination (505) of the channel matrix, the first apparatus 110 may first receive, from the second apparatus, a configuration indicating that a beam report is to be transmitted based on the beam quality. The configuration may have various forms, for example, but not limited to, a CSI report configuration. With the configuration, the first apparatus 110 may be aware that the determined beam quality needs to be transmitted via the beam report and transmit (510) the beam report accordingly.

[0115] The configuration may be transmitted in various ways, for example, via system information, a radio resource control (RRC) signaling, medium access control control element (MAC CE), downlink control information (DCI), and / or the like.

[0116] For example, the network may use a CSI report configuration (e.g., CSI- ReportConfig) to configure the UE to transmit beam reports based on the beam quality metric (Qm) proposed herein, alternatively or additionally to other quality metric(s) (e.g., Ll-RSRP, Ll-SINR).

[0117] FIG. 6 shows a flowchart of an example method 600 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the first apparatus 110 in FIG. 1.

[0118] At block 610, the first apparatus 110 determines a beam quality based on a Gram matrix associated with a channel capacity, the Gram matrix being determined based on a channel matrix associated with at least one transmission beam among a set of transmission beams of a second apparatus and at least one reception beam among a set of reception beams of the first apparatus.

[0119] At block 620, the first apparatus 110 transmits a beam report to the second apparatus based on the determined beam quality.

[0120] In some example embodiments, the first apparatus 110 may determine the channel matrix based on at least one reference signal, the at least one reference signal being transmitted using the at least one transmission beam by the second apparatus and received using the at least one reception beam by the first apparatus; and determining the Gram matrix based on the channel matrix.

[0121] In some example embodiments, the first apparatus 110 may determine the beam quality based on a determinant of the Gram matrix.

[0122] In some example embodiments, the first apparatus 110 may determine a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix; and determining the beam quality based on a determinant of the sum.

[0123] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, and the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0124] In some example embodiments, the scaling factor is determined based on a measured value of a noise and / or interference power.

[0125] In some example embodiments, the channel matrix is associated with at least one of: a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, or a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

[0126] In some example embodiments, the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

[0127] In some example embodiments, the first apparatus 110 may receive, from the second apparatus, a configuration indicating that a beam report is to be transmitted based on the beam quality.

[0128] In some example embodiments, the configuration comprises a Channel State Information (CSI) report configuration.

[0129] In some example embodiments, the first apparatus 110 comprises a terminal device, and the second apparatus 120 comprises a network device.

[0130] FIG. 7 shows a flowchart of an example method 700 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 700 will be described from the perspective of the second apparatus 120 in FIG. 1.

[0131] At block 710, the second apparatus 120 receives, from a first apparatus 110, a beam report associated with a beam quality, wherein the beam quality is determined based on a Gram matrix associated with a channel capacity, and the Gram matrix is determined based on a channel matrix associated with at least one transmission beam among a set of transmission beams of the second apparatus and at least one reception beam among a set of reception beams of the first apparatus.

[0132] In some example embodiments, the channel matrix is determined based on at least one reference signal, the at least one reference signal being transmitted using the at least one transmission beam by the second apparatus and received using the at least one reception beam by the first apparatus.

[0133] In some example embodiments, the beam quality is determined based on a determinant of the Gram matrix.

[0134] In some example embodiments, the beam quality is determined based on a determinant of a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix.

[0135] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, and the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0136] In some example embodiments, the scaling factor is determined based on a measured value of a noise and / or interference power.

[0137] In some example embodiments, the channel matrix is associated with at least one of: a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, or a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

[0138] In some example embodiments, the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

[0139] In some example embodiments, the second apparatus 120 may transmit, to the first apparatus, a configuration indicating that the beam report is to be transmitted based on the beam quality.

[0140] In some example embodiments, the configuration comprises a Channel State Information (CSI) report configuration.

[0141] In some example embodiments, the first apparatus 110 comprises a terminal device, and the second apparatus 120 comprises a network device.

[0142] FIG. 8 illustrates a signaling flow 800 for transmission of a beam report according to some example embodiments of the present disclosure. For the purposes of discussion, the signaling flow 800 will be discussed with reference to FIG. 1, for example, by using the first apparatus 110 and the second apparatus 120. In some embodiments the first apparatus 110 may be discussed with a terminal device, e.g., a UE, and the second apparatus 120 may be discussed with a network device, e.g., a gNB.

[0143] In the signaling flow 800, the first apparatus 110 receives (810), from a second apparatus 120, a configuration indicating that a beam report is to be transmitted based on a beam quality determined using a Gram matrix. The Gram matrix is associated with a channel capacity, and the Gram matrix is determined based on a channel matrix associated with at least one transmission beam among a set of transmission beams of the second apparatus and at least one reception beam among a set of reception beams of the first apparatus.

[0144] The configuration may have various forms, for example, but not limited to, a CSI report configuration. With the configuration, the first apparatus 110 may be aware that the determined beam quality needs to be transmitted via the beam report and transmit (510) the beam report accordingly.

[0145] The configuration may be transmitted in various ways, for example, via system information, a radio resource control (RRC) signaling, medium access control control element (MAC CE), downlink control information (DCI), and / or the like.

[0146] For example, the network may use a CSI report configuration (e.g., CSI-ReportConfig) to configure the UE to transmit beam reports based on the beam quality metric (Qm) proposed herein, alternatively or additionally to other quality metric(s) (e.g., Ll-RSRP, Ll-SINR).

[0147] In some example embodiments, the first apparatus 110 may determine the channel matrix based on at least one reference signal. The at least one reference signal being transmitted using the at least one transmission beam by the second apparatus and received using the at least one reception beam by the first apparatus. Then, the first apparatus 110 may determine the Gram matrix based on the channel matrix; and determine the beam quality based on the Gram matrix.

[0148] The channel matrix may be associated with several factors, which may include, but not limited to, a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams, and / or the like.

[0149] In some example embodiments, for each TX beam in a set of TX beams (bm, m = 1, ... , M) applied by the network, the first apparatus 110, e.g., a UE may determine a corresponding channel matrix (Hm, m = 1, ... , M). This can be based on existing channel sounding and channel estimation methods, e.g., relying on (periodic, semi-persistent and / or aperiodic) multi-port CSI-RS(s). For example, the network may transmit periodically on each TX beam (bm) a (wideband) 2-port CSI-RS (RSm), with each of nt = 2 TX antenna ports corresponding to one polarization of a cross-polarized antenna panel at the network side. The UE may perform measurements on the transmitted CSI-RS(s) on nr = 2 RX antenna ports, each corresponding to one polarization of a cross-polarized antenna panel at the UE side. Based on the measurements, the UE may estimate the nrxnt = 2x2 channel matrix Hm for each TX beam bm.

[0150] In some embodiments, the UE may perform the measurements using different RX beams from a set of RX beams (ci, 1 = 1, ... , L) and determine a channel matrix Hm,i for each TX / RX beam pair (bm, ci) of several possible TX / RX beam pairs. For example, this may be enabled by the network transmitting CSI-RS with repetition enabled (repetition = ‘ON’). In this case, the term “beam quality” used herein may be understood as the quality of a particular TX / RX beam pair.

[0151] In some embodiments, the second apparatus 120, e g., a gNB which may be referred to as the network, may be able to use more than one TX beam simultaneously for transmission to a same UE (e.g., multi-TRP operation). For example, the network may transmit using 2 TX beams simultaneously, each with 2 polarizations, thus allowing up to 4 spatially multiplexed transmission layers. In this case, the UE (e.g., multi-panel, multi-RX) may perform measurements to determine a nrxnt = 4x4 channel matrix Hmi.m2 for each TX beam pair (bmi, bm2) of several possible TX beam pairs (or more generally TX beam “groups”, as in “Group Based Beam Reporting”, GBBR). In this case, the term “beam quality” used herein may be understood as the quality of a particular TX beam pair (group). Moreover, the UE may perform such measurements using different RX beam pairs (more generally, RX beam “groups”), and determine a nr n, = 4x4 channel matrix Hmi.m2.ii.12 for each of several possible combinations of a TX beam pair (bmi, bm2) and a RX beam pair (cn, C12). In this case, the term “beam quality” used herein may be understood as the quality of a particular combination of a TX beam pair (group) and a RX beam pair (group).

[0152] In some example embodiments, the number of TX antenna ports and / or RX antenna ports per TX beam may be larger than 2.

[0153] Based on the channel matrix, the first apparatus 110 may determine the Gram matrix associated with a channel capacity. In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception. Alternatively, or in addition, the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0154] For example, in the case where the nrxnt channel matrix Hm has full rank r = min(nt, nr), the Gram matrix may be determined as if nt <nr, and determined as HmHm^ if nt >nr,

[0155] On the basis of the Gram matrix, the first apparatus 110 may determine the beam quality for the at least one transmission beam and / or the at least one reception beam. The beam quality may be determined in a variety of ways. In some example embodiments, the first apparatus 110 may further determine the beam quality based on a determinant of the Gram matrix.

[0156] In some example implementations, based on the channel matrix Hm for each TX beam bm, the first apparatus 110, e.g., the UE, may determine a beam quality Qm by calculating a determinant. The same applies to the cases described above of a channel matrix Hm,i for a TX / RX beam pair (with quality Qm,i), a channel matrix Hmi,m2 for a TX beam pair (group) (with quality Qmi,m2), or a channel matrix Hmi.m2,11,12 for a combination of a TX beam pair (group) and a RX beam pair (group) (with quality Qmi,m2,11,12). It is to be understood that, although this example focuses on the case of a channel matrix Hm corresponding to a TX beam bm, what follows applies equally well to the other cases described above.

[0157] In some cases, when the nrxnt channel matrix Hm has full rank r = min(nt, nr), the beam quality Qm may be calculated: when nt <nr, based on the Gram determinant Tm = detlHm^Hm), and when nt >nr, based on the Gram determinant T’m = det(HmHm / / ), corresponding to the (squared) r-dimensional volume of the parallelotope, P(Hm) or generated by the r (linearly independent) column vectors of Hm or HmH, respectively.

[0158] Alternatively, in some example embodiments, when determining the beam quality, the first apparatus 110 may further determine a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix, and determine the beam quality based on a determinant of the sum. The scaling factor may be determined based on a measured value of a noise and / or interference power.

[0159] Specifically, the beam quality Qm may be calculated based on a determinant of a sum of an identity matrix plus a scaled Gram matrix, e.g., det(Int + q Hm^Hm) or det(IIlf + qHmHmH), wherein the scaling factor (q) depends on a noise power. For example, the scaling factor (q) may be derived from a measured Ll-SINR.

[0160] In other cases, either when the channel matrix Hm has full rank (i.e., r = min(nt, nr)) or when the channel matrix Hm is rank-deficient (i.e., r <min(nt, nr)), the beam quality Qm may be calculated as the product of the squares of the non-zero singular values of Hm. As an example, if gi, 02, ... , Gr are the non-zero singular values of Hm, then Qm = oi2O22 ... Gr2. Note that the squared singular values (c,2) of Hm are equal to the eigenvalues (Xi) of the Gram matrix Hm2Hm (nt <nr) or HmHm" (nt >nr).

[0161] In other cases, either when the channel matrix Hm has full rank (i.e., r = min(nt, nr)) or when the channel matrix Hm is rank-deficient (i.e., r <min(nt, nr)), the beam quality Qm may be calculated as Qm = (l+qGi2)(l+qo22) ... (l+qGr2), where gi, G2, ... , Gr are the non-zero singular values of Hm, and the scaling factor (q) depends on a noise power.

[0162] Still referring to FIG. 8, based on the configuration, the first apparatus 110 transmits (815) the beam report to the second apparatus 120. Correspondingly, the second apparatus 120 receives (820) the beam report from the first apparatus 110.

[0163] The beam report may indicate the beam quality, a beam corresponding to the beam quality and or other information. The beam report may include, for example, the value of the beam quality, an index of the corresponding beam, and / or the like.

[0164] In an example implementation, after determining the beam quality Qm for each TX beam bm (m = 1, ... , M), the first apparatus 110, e.g., the UE, may transmit a beam report to the second apparatus 120, e.g., the network, based on the determined beam qualities. The UE may be configured to do so. In some cases, the UE may be configured to indicate a set of best beams (e.g., N best beams). The beam report may also include the corresponding beam qualities.

[0165] FIG. 9 shows a flowchart of an example method 900 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 900 will be described from the perspective of the first apparatus 110 in FIG. 1.

[0166] At block 910, the first apparatus 110 receives, from a second apparatus 120, a configuration indicating that a beam report is to be transmitted based on a beam quality determined using a Gram matrix associated with a channel capacity, the Gram matrix being determined based on a channel matrix associated with at least one transmission beam among a set of transmission beams of the second apparatus and at least one reception beam among a set of reception beams of the first apparatus.

[0167] At block 920, the first apparatus 110 transmits the beam report to the second apparatus based on the configuration.

[0168] In some example embodiments, the first apparatus 110 may determine the channel matrix based on at least one reference signal, the at least one reference signal being transmitted using the at least one transmission beam by the second apparatus and received using the at least one reception beam by the first apparatus; determine the Gram matrix based on the channel matrix; and determine the beam quality based on the Gram matrix.

[0169] In some example embodiments, the first apparatus 110 may determine the beam quality based on a determinant of the Gram matrix.

[0170] In some example embodiments, the first apparatus 110 may determine a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix; and determine the beam quality based on a determinant of the sum.

[0171] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, and the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0172] In some example embodiments, the scaling factor is determined based on a measured value of a noise and / or interference power.

[0173] In some example embodiments, the channel matrix is associated with at least one of: a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, or a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

[0174] In some example embodiments, the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

[0175] In some example embodiments, the configuration comprises a Channel State Information (CSI) report configuration.

[0176] In some example embodiments, the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

[0177] FIG. 10 shows a flowchart of an example method 1000 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1000 will be described from the perspective of the second apparatus 120 in FIG. 1

[0178] At block 1010, the second apparatus 120 transmits, to a first apparatus 110, a configuration indicating that a beam report is to be transmitted based on a beam quality determined using a Gram matrix associated with a channel capacity, the Gram matrix being determined based on a channel matrix associated with at least one transmission beam among a set of transmission beams of the second apparatus and at least one reception beam among a set of reception beams of the first apparatus.

[0179] At block 1020, the second apparatus 120 receives the beam report from the first apparatus 110.

[0180] In some example embodiments, the channel matrix is determined based on at least one reference signal, the at least one reference signal being transmitted using the at least one transmission beam by the second apparatus and received using the at least one reception beam by the first apparatus.

[0181] In some example embodiments, the beam quality is determined based on a determinant of the Gram matrix.

[0182] In some example embodiments, the beam quality is determined based on a determinant of a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix.

[0183] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, and the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0184] In some example embodiments, the scaling factor is determined based on a measured value of a noise and / or interference power.

[0185] In some example embodiments, the channel matrix is associated with at least one of: a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, or a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

[0186] In some example embodiments, the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

[0187] In some example embodiments, the configuration comprises a Channel State Information (CSI) report configuration.

[0188] In some example embodiments, the first apparatus 110 comprises a terminal device, and the second apparatus 120 comprises a network device.

[0189] In some example embodiments, a first apparatus capable of performing any of the method 400 (for example, the first apparatus 110 in FIG. 1 may comprise means for performing the respective operations of the method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1.

[0190] In some example embodiments, the first apparatus comprises means for determining a channel matrix based on at least one reference signal, the at least one reference signal being transmitted using at least one transmission beam among a set of transmission beams by a second apparatus and received using at least one reception beam among a set of reception beams by the first apparatus; means for determining a Gram matrix associated with a channel capacity based on the channel matrix; and means for determining a beam quality for at least one of the at least one transmission beam or the at least one reception beam based on the Gram matrix.

[0191] In some example embodiments, the first apparatus further comprises: means for determining the beam quality based on a determinant of the Gram matrix.

[0192] In some example embodiments, the first apparatus further comprises: means for determining a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix; and means for determining the beam quality based on a determinant of the sum.

[0193] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, and the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0194] In some example embodiments, the scaling factor is determined based on a measured value of a noise and / or interference power.

[0195] In some example embodiments, the channel matrix is associated with at least one of: a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, or a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

[0196] In some example embodiments, the first apparatus further comprises: means for transmitting a beam report to the second apparatus based on the determined beam quality.

[0197] In some example embodiments, the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

[0198] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, a configuration indicating that a beam report is to be transmitted based on the beam quality.

[0199] In some example embodiments, the at least one reference signal comprises a Channel State Information - Reference Signal (CSI-RS), and the configuration comprises a CSI report configuration.

[0200] In some example embodiments, the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

[0201] In some example embodiments, the first apparatus further comprises means for performing other operations in some example embodiments of the method 400 or the first apparatus 110. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the first apparatus.

[0202] In some example embodiments, a first apparatus capable of performing any of the method 600 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1.

[0203] In some example embodiments, the first apparatus comprises means for determining a beam quality based on a Gram matrix associated with a channel capacity, the Gram matrix being determined based on a channel matrix associated with at least one transmission beam among a set of transmission beams of a second apparatus and at least one reception beam among a set of reception beams of the first apparatus; and means for transmitting a beam report to the second apparatus based on the determined beam quality.

[0204] In some example embodiments, the first apparatus further comprises: means for determining the channel matrix based on at least one reference signal, the at least one reference signal being transmitted using the at least one transmission beam by the second apparatus and received using the at least one reception beam by the first apparatus; and means for determining the Gram matrix based on the channel matrix.

[0205] In some example embodiments, the first apparatus further comprises: means for determining the beam quality based on a determinant of the Gram matrix.

[0206] In some example embodiments, the first apparatus further comprises: means for determining a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix; and means for determining the beam quality based on a determinant of the sum.

[0207] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, and the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0208] In some example embodiments, the scaling factor is determined based on a measured value of a noise and / or interference power.

[0209] In some example embodiments, the channel matrix is associated with at least one of a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, or a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

[0210] In some example embodiments, the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

[0211] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, a configuration indicating that a beam report is to be transmitted based on the beam quality.

[0212] In some example embodiments, the configuration comprises a Channel State Information (CSI) report configuration.

[0213] In some example embodiments, the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

[0214] In some example embodiments, the first apparatus further comprises means for performing other operations in some example embodiments of the method 600 or the first apparatus 110. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the first apparatus.

[0215] In some example embodiments, a second apparatus capable of performing any of the method 700 (for example, the second apparatus 120 in FIG. 1) may comprise means for performing the respective operations of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second apparatus 120 in FIG. 1.

[0216] In some example embodiments, the second apparatus comprises means for receiving, from a first apparatus, a beam report associated with a beam quality, wherein the beam quality is determined based on a Gram matrix associated with a channel capacity, and the Gram matrix is determined based on a channel matrix associated with at least one transmission beam among a set of transmission beams of the second apparatus and at least one reception beam among a set of reception beams of the first apparatus.

[0217] In some example embodiments, the channel matrix is determined based on at least one reference signal, the at least one reference signal being transmitted using the at least one transmission beam by the second apparatus and received using the at least one reception beam by the first apparatus.

[0218] In some example embodiments, the beam quality is determined based on a determinant of the Gram matrix.

[0219] In some example embodiments, the beam quality is determined based on a determinant of a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix.

[0220] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, and the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0221] In some example embodiments, the scaling factor is determined based on a measured value of a noise and / or interference power.

[0222] In some example embodiments, the channel matrix is associated with at least one of: a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, or a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

[0223] In some example embodiments, the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

[0224] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, a configuration indicating that the beam report is to be transmitted based on the beam quality.

[0225] In some example embodiments, the configuration comprises a Channel State Information (CSI) report configuration.

[0226] In some example embodiments, the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

[0227] In some example embodiments, the second apparatus further comprises means for performing other operations in some example embodiments of the method 700 or the second apparatus 120. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the second apparatus.

[0228] In some example embodiments, a first apparatus capable of performing any of the method 900 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1.

[0229] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a configuration indicating that a beam report is to be transmitted based on a beam quality determined using a Gram matrix associated with a channel capacity, the Gram matrix being determined based on a channel matrix associated with at least one transmission beam among a set of transmission beams of the second apparatus and at least one reception beam among a set of reception beams of the first apparatus; and means for transmitting the beam report to the second apparatus based on the configuration.

[0230] In some example embodiments, the first apparatus further comprises: means for determining the channel matrix based on at least one reference signal, the at least one reference signal being transmitted using the at least one transmission beam by the second apparatus and received using the at least one reception beam by the first apparatus; means for determining the Gram matrix based on the channel matrix; and means for determining the beam quality based on the Gram matrix.

[0231] In some example embodiments, the first apparatus further comprises: means for determining the beam quality based on a determinant of the Gram matrix.

[0232] In some example embodiments, the first apparatus further comprises: means for determining a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix; and means for determining the beam quality based on a determinant of the sum.

[0233] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, and the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0234] In some example embodiments, the scaling factor is determined based on a measured value of a noise and / or interference power.

[0235] In some example embodiments, the channel matrix is associated with at least one of: a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, or a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

[0236] In some example embodiments, the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

[0237] In some example embodiments, the configuration comprises a Channel State Information (CSI) report configuration.

[0238] In some example embodiments, the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

[0239] In some example embodiments, the first apparatus further comprises means for performing other operations in some example embodiments of the method 900 or the first apparatus 110. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the first apparatus.

[0240] In some example embodiments, a second apparatus capable of performing any of the method 1000 (for example, the second apparatus 120 in FIG. 1) may comprise means for performing the respective operations of the method 1000. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second apparatus 120 in FIG. I.

[0241] In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, a configuration indicating that a beam report is to be transmitted based on a beam quality determined using a Gram matrix associated with a channel capacity, the Gram matrix being determined based on a channel matrix associated with at least one transmission beam among a set of transmission beams of the second apparatus and at least one reception beam among a set of reception beams of the first apparatus; and means for receiving the beam report from the first apparatus.

[0242] In some example embodiments, the channel matrix is determined based on at least one reference signal, the at least one reference signal being transmitted using the at least one transmission beam by the second apparatus and received using the at least one reception beam by the first apparatus.

[0243] In some example embodiments, the beam quality is determined based on a determinant of the Gram matrix.

[0244] In some example embodiments, the beam quality is determined based on a determinant of a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix.

[0245] In some example embodiments, the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, and the Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

[0246] In some example embodiments, the scaling factor is determined based on a measured value of a noise and / or interference power.

[0247] In some example embodiments, the channel matrix is associated with at least one of: a transmission beam in the set of transmission beams, a reception beam in the set of reception beams, a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams, a group of transmission beams in the set of transmission beams, a group of reception beams in the set of reception beams, or a first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

[0248] In some example embodiments, the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

[0249] In some example embodiments, the configuration comprises a Channel State Information (CSI) report configuration.

[0250] In some example embodiments, the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

[0251] In some example embodiments, the second apparatus further comprises means for performing other operations in some example embodiments of the method 1000 or the second apparatus 120. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the second apparatus.

[0252] FIG. 11 is a simplified block diagram of a device 1100 that is suitable for implementing example embodiments of the present disclosure. The device 1100 may be provided to implement a communication device, for example, the first apparatus 110 or the second apparatus 120 as shown in FIG. 1. As shown, the device 1100 includes one or more processors 1110, one or more memories 1120 coupled to the processor 1110, and one or more communication modules 1140 coupled to the processor 1110.

[0253] The communication module 1140 is for bidirectional communications. The communication module 1140 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 1140 may include at least one antenna.

[0254] The processor 1110 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1100 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0255] The memory 1120 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 1124, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 1122 and other volatile memories that will not last in the power-down duration.

[0256] A computer program 1130 includes computer executable instructions that are executed by the associated processor 1110. The instructions of the program 1130 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 1130 may be stored in the memory, e.g., the ROM 1124. The processor 1110 may perform any suitable actions and processing by loading the program 1130 into the RAM 1122.

[0257] The example embodiments of the present disclosure may be implemented by means of the program 1130 so that the device 1100 may perform any process of the disclosure as discussed with reference to FIG. 3 to FIG. 10. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0258] In some example embodiments, the program 1130 may be tangibly contained in a computer readable medium which may be included in the device 1100 (such as in the memory 1120) or other storage devices that are accessible by the device 1100. The device 1100 may load the program 1130 from the computer readable medium to the RAM 1122 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e g., RAM vs. ROM).

[0259] FIG. 12 shows an example of the computer readable medium 1200 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1200 has the program 1130 stored thereon.

[0260] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0261] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computerexecutable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0262] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0263] In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0264] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0265] Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.

[0266] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A first apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to:determine a channel matrix based on at least one reference signal, the at least one reference signal being transmitted using at least one transmission beam among a set of transmission beams by a second apparatus and received using at least one reception beam among a set of reception beams by the first apparatus;determine a Gram matrix associated with a channel capacity based on the channel matrix; anddetermine a beam quality for at least one of the at least one transmission beam or the at least one reception beam based on the Gram matrix.

2. The first apparatus of claim 1, wherein the first apparatus is caused to:determine the beam quality based on a determinant of the Gram matrix.

3. The first apparatus of claim 1, wherein the first apparatus is caused to:determine a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix; anddetermine the beam quality based on a determinant of the sum.

4. The first apparatus of any of claims 1 to 3, wherein the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, andthe Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

5. The first apparatus of claim 3, wherein the scaling factor is determined based on a measured value of a noise and / or interference power.

6. The first apparatus of any of claims 1 to 5, wherein the channel matrix is associated with at least one of:a transmission beam in the set of transmission beams,a reception beam in the set of reception beams,a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams,a group of transmission beams in the set of transmission beams,a group of reception beams in the set of reception beams, ora first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

7. The first apparatus of any of claims 1 to 6, wherein the first apparatus is caused to:transmit a beam report to the second apparatus based on the determined beam quality.

8. The first apparatus of claim 7, wherein the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

9. The first apparatus of any of claims 1 to 8, wherein the first apparatus is caused to:receive, from the second apparatus, a configuration indicating that a beam report is to be transmitted based on the beam quality.

10. The first apparatus of claim 9, wherein the at least one reference signal comprises a Channel State Information - Reference Signal (CSI-RS), and the configuration comprises a CSI report configuration.

11. The first apparatus of any of claims 1 to 10, wherein the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

12. A method comprising:determining a channel matrix based on at least one reference signal, the at least one reference signal being transmitted using at least one transmission beam among a set of transmission beams by a second apparatus and received using at least one reception beam among a set of reception beams by the first apparatus;determining a Gram matrix associated with a channel capacity based on the channel matrix; anddetermining a beam quality for at least one of the at least one transmission beam or the at least one reception beam based on the Gram matrix.

13. The method of claim 12, further comprising:determining the beam quality based on a determinant of the Gram matrix.

14. The method of claim 12, further comprising:determining a sum of the Gram matrix, multiplied by a scaling factor, plus an identity matrix; anddetermining the beam quality based on a determinant of the sum.

15. The method of any of claims 12 to 14, wherein the Gram matrix is in a first form if a number of antenna ports for transmission is less than or equal to a number of antenna ports for reception, andthe Gram matrix is in a second form if the number of antenna ports for transmission is larger than the number of antenna ports for reception.

16. The method of claim 14, wherein the scaling factor is determined based on ameasured value of a noise and / or interference power.

17. The method of any of claims 12 to 16, wherein the channel matrix is associated with at least one of:a transmission beam in the set of transmission beams,a reception beam in the set of reception beams,a pair of a transmission beam in the set of transmission beams and a reception beam in the set of reception beams,a group of transmission beams in the set of transmission beams,a group of reception beams in the set of reception beams, ora first group of transmission beams in the set of transmission beams and a second group of reception beams in the set of reception beams.

18. The method of any of claims 12 to 17, further comprising:transmitting a beam report to the second apparatus based on the determined beam quality.

19. The method of claim 18, wherein the beam report comprises at least one of the beam quality or a beam corresponding to the beam quality.

20. The method of any of claims 12 to 19, further comprising:receiving, from the second apparatus, a configuration indicating that a beam report is to be transmitted based on the beam quality.

21. The method of claim 20, wherein the at least one reference signal comprises a Channel State Information - Reference Signal (CSI-RS), and the configuration comprises a CSI report configuration.

22. The method of any of claims 12 to 21, wherein the first apparatus comprises aterminal device, and the second apparatus comprises a network device.

23. A first apparatus comprising:means for determining a channel matrix based on at least one reference signal, the5 at least one reference signal being transmitted using at least one transmission beam among a set of transmission beams by a second apparatus and received using at least one reception beam among a set of reception beams by the first apparatus;means for determining a Gram matrix associated with a channel capacity based on the channel matrix; and10 means for determining a beam quality for at least one of the at least one transmission beam or the at least one reception beam based on the Gram matrix.

24. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of any of claims 12-22.Application No: GB2410800.3Examiner:Dr John CullenClaims searched: 1-24Date of search: 23 December 2024Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance X 1, 3, 5-12, 14, 16-24 US 2021 / 0143879 Al (JI et al.) See paras 44-76 and 138. X 1,3, 5-12, 14, 16, 17, 20-24 US 2015 / 0236774 Al (SON et al.) See Abstract, Figures 3B, 4 and 9, equations 2 and 3 and paragraphs 65-71, 97-106, 143-163, 174, 175 and 201. X 1, 3, 5-8, 11, 12, 14, 16-19, 22-24 US 2014 / 0126620 Al (MALTSEV et al.) X 1, 3, 5, 6, 12, 14, 16, 17, 23, 24 US 2014 / 0341310 Al (RAHMAN et al.) See paras 115, 118, 128-131 and 141, and Figs 5, 14 and 16. X 1, 3, 5-12, 14,16-24 US 10879967 B2 (KIM et al.) See Figures 2B, 3, 4 and 8, equations 2 and 6, lines 1-37 of column 19 and lines 5-28 of column 21. A ICC 2003. 2003 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS. ANCHORAGE, AK, MAY 11 - 15, 2003, IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, NEW YORK, NY : IEEE, US, vol. VOL. 1 OF 5, 2003, Clerckx B et al., Mutual coupling effects on the channel capacity and the space-time processing of MIMO See equations 3 and 6 A ——— 3GPP TS 38.214 V18.2.0, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Physical layer procedures for data (Release 18)", March 2024 See Section 5.2.2.1v Au Document indicating lack of novelty or inventive step A Document indicating technological background and or state of the art. Y Document indicating lack of inventive step if combined with one or more other documents of same category. P Document published on or after the declared priority date but before the filing date of this invention. & Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.www.gov.uk / ipoField of Search:Search of GB, EP, WO &US patent documents classified in the following areas of the UKCX :Worldwide search of patent documents classified in the following areas of the IPC____________ H04B___________________________________________________ The following online and other databases have been used in the preparation of this search report Search-Patent, Search-NPLInternational Classification:Subclass Subgroup Valid From H04B 0007 / 06 01 / 01 / 2006www.gov.uk / ipo

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