EP4666414A1

EP4666414A1 - Devices, methods and apparatuses for spatial adaptation

Info

Publication number: EP4666414A1
Application number: EP23820781.5A
Authority: EP
Inventors: Youngsoo Yuk; Matha DEGHEL
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2023-02-16
Filing date: 2023-11-30
Publication date: 2025-12-24
Also published as: GB202302209D0; JP2026506680A; KR20250138258A; MX2025009460A; CN120712722A; GB2627237A; WO2024170123A1

Abstract

Embodiments of the present disclosure disclose devices, methods and apparatuses for spatial adaption. A terminal device receives, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations. Each of the spatial configurations associates with an energy level or antenna elements. The terminal device further performs at least one reference signal measurement based on the measurement configuration.

Description

DEVICES, METHODS AND APPARATUSES FOR SPATIAL ADAPTATION

FIELD

[0001] Embodiments of the present disclosure generally relate to the field of communication, and in particular, to devices, methods, apparatuses and computer readable storage medium for spatial adaptation.

BACKGROUND

[0002] Network energy saving is of great importance for environmental sustainability, to reduce environmental impact (greenhouse gas emissions), and for operational cost savings. As new radio (NR), also known as fifth-generation technology standard for broadband cellular networks (5G), is becoming pervasive across industries and geographical areas, handling more advanced services and applications requiring very high data rates, networks are being denser, use more antennas, larger bandwidths and more frequency bands, which means an increasing energy consumption.

[0003] Therefore, the environmental impact of 5G and the operational operating expense need to stay under control, and improved solutions for energy saving in 5G need to be further investigated and improved.

SUMMARY

[0004] In general, example embodiments of the present disclosure provide devices, methods, apparatuses and computer readable storage medium for channel state information (CSI) measurement and reporting framework for spatial adaption.

[0005] In a first aspect, there is provided a terminal device. The terminal device may comprise one or more transceivers; and one or more processors coupled to the one or more transceivers, wherein the one or more transceivers are configured with the one or more processor to cause the terminal device to: receive, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and perform at least one reference signal measurement based on the measurement configuration. [0006] In a second aspect, there is provided a network device. The network device may comprise one or more transceivers; and one or more processors coupled to the one or more transceivers, and the one or more transceivers are configured with the one or more processor to cause the network device to: transmit, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and receive at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

[0007] In a third aspect, there is provided a method at a terminal device. The method may comprise: receiving, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and performing at least one reference signal measurement based on the measurement configuration.

[0008] In a fourth aspect, there is provided a method at a network device. The method may comprise: transmitting, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and receiving at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

[0009] In a fifth aspect, there is provided an apparatus of a terminal device. The apparatus may comprise: means for receiving, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and means for performing at least one reference signal measurement based on the measurement configuration.

[0010] In a sixth aspect, there is provided an apparatus of a network device. The apparatus may comprise: means for transmitting, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and means for receiving at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

[0011] In a seventh aspect, there is provided a terminal device. The terminal device may comprise at least one processor; and at least one memory including computer program codes, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to: receive, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and perform at least one reference signal measurement based on the measurement configuration.

[0012] In an eighth aspect, there is provided a network device. The network device may comprise at least one processor; and at least one memory including computer program codes, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the network device to: transmit, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and receive at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

[0013] In a ninth aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method according to third or fourth aspect.

[0014] In a tenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: receive, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and perform at least one reference signal measurement based on the measurement configuration.

[0015] In an eleventh aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: transmit, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and receive at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

[0016] In a twelfth aspect, there is provided a terminal device. The terminal device may comprise receiving circuitry configured to receive, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and measurement circuitry configured perform at least one reference signal measurement based on the measurement configuration.

[0017] In a thirteenth aspect, there is provided a network device. The network device may comprise transmitting circuitry configured to transmit, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and receiving circuitry configured to receive at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

[0018] 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

[0019] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0020] FIG. 1 illustrates an example network environment in which example embodiments of the present disclosure may be implemented;

[0021] FIG. 2 illustrates example spatial configurations with different numbers of active/unmuted antenna/spatial elements;

[0022] FIG. 3 illustrates an example flowchart of a method implemented at a terminal device according to example embodiments of the present disclosure;

[0023] FIG. 4A illustrates an example association between spatial configurations and subband configurations;

[0024] FIG. 4B illustrates another example association between spatial configurations and sub-band configurations;

[0025] FIG. 5 illustrates an example flowchart of a method implemented at a network device according to example embodiments of the present disclosure;

[0026] FIG. 6 illustrates an example signaling process for reporting measurements on reference signals according to some embodiments of the present disclosure;

[0027] FIG. 7 illustrates an example simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure; and

[0028] FIG. 8 illustrates an example block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

[0029] Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

[0030] 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. The disclosure described herein can be implemented in various manners other than the ones described below.

[0031] 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.

[0032] 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.

[0033] It shall be understood that although the terms “first” and “second” etc. 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. 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.

[0034] 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. As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” 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.

[0035] 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.

[0036] 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) 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.

[0037] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as 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 communication protocols, including, but not limited to, the third generation (3G), the fourth generation (4G), 4.5G, the future fifth generation (5G) 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.

[0038] 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), a new radio (NR) NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.

[0039] 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. In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0040] The term “transceiver” may refer to any device that may be coupled to one or more antennas or antenna ports to wirelessly transmit and/or receive communication signals. The antennas or antenna ports may be the same or different types. The antennas or antenna ports may be located in different positions of an apparatus. One or more transceivers allow the apparatus to communicate with other devices that may be wired and/or wireless. The one or more transceivers may include processors, controllers, radios, sockets, plugs, buffers, or the like circuits to form one or more communication channels to one or more radio frequency units. The one or more transceivers may be integrated in an apparatus or a system, for example a cellular communication apparatus or system, a WLAN system, or a short ranging system for example Bluetooth system.

[0041] As used herein, the term “beam” may refer to a communication resource. Different beams may be considered as different resources. Abeam may also be represented as a spatial filter. A technology for forming a beam may be a beamforming technology or another technology. The beamforming technology may be specifically a digital beamforming technology, analog beamforming technology, or a hybrid digital/analog beamforming technology. A communication device (including the terminal device and the network device) may communicate with another communication device through one or more beams. One beam may include one or more antenna ports and be configured for a data channel, a control channel, or the like. One or more antenna ports forming one beam may also be considered as an antenna port set. Abeam may be configured with a set of resource, or a set of resource for measurement, and a beam may be represented by for example a reference signal and/or related resource for the reference signal. A beam may also represent by a reference cell identifier or resource identifier.

[0042] As used herein, the term “beamforming” may be referred to as spatial filtering, directional transmission, or directional reception. Beamforming is a signal processing technique that may be used at a transmitting device and/or a receiving device to shape or steer an antenna beam along a spatial path between the transmitting device and the receiving device. Beamforming may rely on antenna elements of an antenna array for signals propagating at specific orientations.

[0043] In current channel state information (CSI) framework, CSI reference signals (CSI- RSs) are UE-specifically configured in radio resource control (RRC). However, CSI-RS reference signals may be shared among many terminal devices, i.e., more than one terminal device may be configured to receive the same resource elements (RE). If all the terminal devices within a cell share the same CSI-RS resources, the reference signals may be referred as cell specific CSI-RS. If only a group of terminal devices within the cell share the same CSI-RS resources, such arrangement may be referred as group-specific CSI-RS. And if each terminal device has its own CSI-RS resource, it may be referred as UE-specific CSI-RS. Note that this arrangement is only known to the gNB, the terminal device is not aware if the CSI-RS resource(s) is/are shared with another terminal device or not.

[0044] In general, in order to save downlink (DL) resources, the gNB would try to use cellspecific or group-specific CSI-RS resources. The worst case of DL overhead is with UE- specific CSI-RS where the DL overhead increases linearly with the number of UE in the cell.

[0045] CSI-RS has many functions in NR, and example functions may include:

• CSI-RS for DL CSI acquisition

• CSI-RS for beam management (BM) (based on Ll-RSRP)

• CSI-RS for tracking (TRS)

• UL CSI acquisition in reciprocity-based UL precoding

[0046] In some applications (e.g., CSI-RS for BM), CSI-RS may be spatially beamformed into different directions. In general, a terminal device may be configured with up to 48 report configurations per component carrier (CC) and 4 report configurations per bandwidth part (BWP). One CSI resource configuration within 1 report configuration may be configured with up to 16 resource sets (aperiodic CSI) and 1 resource set (otherwise). In each CSI resource set, there are up to 64 non-zero-power (NZP) CSI-RS resources and in each NZP-CSLRS resource, there are up to 32 antenna ports.

[0047] For CSI acquisition, the terminal device may be configured also with a codebook type. Given the measured channel across a CSI-RS resource, the terminal device may choose a favorite codeword from the specified codebook, i.e., precoding matrix indicator (PMI), along with channel quality indicator (CQI), rank indicator (RI). The terminal device may also be configured to measure several CSI-RS resources (up to 8) within a resource set and report the favorite resource, CSI-RS resource indicator (CRI), along with PMI, CQI and rank indication (RI) which corresponds to that selected resource.

[0048] As new radio (NR), also known as 5G, is becoming pervasive across industries and geographical areas, handling more advanced services and applications requiring very high data rates, networks are being denser, use more antennas, larger bandwidths and more frequency bands, which means an increased energy consumption, which means an increasing energy consumption.

[0049] Regarding frequency-granularity, the CSI report setting also defines which part of the bandwidth the CSI should correspond to, and in addition, what granularity in frequency the CSI should have. To accomplish this, the bandwidth of a BWP is divided into a number of sub-bands. Based on this division of the BWP into sub-bands, the CSI reporting band for the CSI report is defined as an arbitrary subset of sub-bands of the BWP, which is indicated as a bitmap where each bit corresponds to one sub-band. The terminal device should only take the sub-bands in the CSI reporting band into account when determining the CSI. The CSI sub-band configuration may be part of a report configuration in the frequency domain.

[0050] The CSI report setting also defines the respective frequency-granularity of the PMI and CQI, which can be either wideband or sub-band. For wideband PMI/CQI, a single PMI/CQI corresponding to the entire CSI reporting band is reported whereas for sub-band PMI/CQI, a separate PMI/CQI is reported for each constituent sub-band in the CSI reporting band. Specifically, the report configuration in the frequency domain may comprise CQI format indicator (which indicates whether the UE shall report a single (wideband) or multiple (sub-band) CQI), PMI format indicator (which indicates whether the UE shall report a single (wideband) or multiple (sub-band) PMI).

[0051] Currently, energy consumption has become a key part of the operators’ operating expense (OPEX). Most of the energy consumption comes from the radio access network and in particular from the Active Antenna Unit (AAU), and data centers and fiber transport also account for a smaller share of the energy consumption. The power consumption of a radio access may be split into two parts: the dynamic part and the static part. The dynamic part is the energy part to power only consumed when data transmission/reception is ongoing. The static part is the energy part consumed all the time to maintain the necessary operation of the radio access devices, even when the data transmission/reception is not on-going.

[0052] It is noted in the approved third generation partnership project (3GPP) release 18 (Rel-18) work item description (WID) that spatial adaptation will be specified in Rel-18 New Radio (NR). Approved Rel-18 WID is partially copied as follows:

[0053] Therefore, the environmental impact of 5G and the operational operating expense need to stay under control, and improved solutions for energy saving in 5G need to be further investigated and improved.

[0054] In the present disclosure, it is focused on the problem of CSI reporting in order to enable efficient spatial adaptation procedure which is captured in the above objective. There is provided a solution related to CSI configuration, measurement, and/or reporting to enable efficient spatial adaptation procedure.

[0055] The focus is one of the potential proposals which is about sharing the same CSI-RS resource for measuring/evaluating different muting/unmuting (or active/inactive) patterns, for gNB power saving to avoid multiple CSI-RS transmission. For instance, multiple sets of antenna ports indicated could be corresponding to different number of (active) ports. This is a valid approach as it essentially decreases the DL overhead due to the use of a single CSI- RS resource to ‘sound’ different spatial muting/unmuting (or active/inactive) patterns. More generally, we consider the case where one CSI report configuration/ setting is used to evaluate multiple spatial patterns. The present disclosure may use muting patterns instead of muting/unmuting (or active/inactive) patterns for simplicity reason, but it should be understood that inactive pattern may have the same meaning of muting, and unmuting or active patterns may indicate the antenna/spatial elements for transmission instead of muting/inactive of the antenna/spatial elements for transmission in muting/inactive pattern. It should be noted that CSI-RS is one example, but not limited only to CSI-RS. Other RS may also be possible for example demodulation reference signal (DMRS), tracking RS etc. [0056] Specifically, because the main purpose of the spatial adaptation is to reduce the energy consumption in gNB, different spatial patterns may be associated with different antenna ports configurations (i.e. antenna muting pattern). The size of CSI feedback information bits may be different according to the antenna muting pattern. If shared CSI- RS resource is used, the size of CSI feedback information may be different according to the corresponding antenna muting patterns. Since the gNB may not know what antenna ports configurations the UE selects for the report, it is assumed that the UL resource size for CSI feedback is reserved for the maximum. Also, the optimal CSI reporting configuration may be different for different antenna muting patterns. In view of this, the embodiments of the present disclosure provide solutions for the efficient CSI feedback with respect to UE’s selection of antenna muting patterns. In addition, when the number of spatial elements is reduced, the beam pattern from lower (resp., larger) number of spatial elements may be widen (resp., narrower) due to low (resp., high) spatial resolution. A wider beam may increase the number of multipaths, which then results in higher delay spread; a tighter beam may decrease the number of multipaths which then results in lower delay spread. High delay spread is reflected as frequency selectivity in channel. In other words, the channels with different spatial patterns may have different frequency selectivity characteristics.

[0057] When the antenna muting pattern is changed, the number of ports P and CSI codebook parameter (Nl, N2, 01, 02) are changed, where (Nl, N2, 01, 02) are number of antenna rows, number of antenna columns, horizontal oversampling ratio and vertical oversampling ratio, respectively. The size of PMI reporting is a function of these parameters, and when UE reports PMI with/for different muting pattern, the size of PMI reporting is different.

[0058] For example, for CSI type I codebook, the number of antenna patterns changed from 32 to 16 or from 8 or 4, codebook parameters are changed from (4, 4, 4, 4) to (4, 2, 4, 4) or from (2, 2, 4, 4) or (4, 1,4,1), and UE reports rank=4 and configured with NSB sub-bands, the required number of bits for PMI reporting may be for example as follows:

P=32: (4, 4, 4, 4): ii.i (3bits), ii,2 (4bits), ii.s (2bits), i2 ( Ibit per sub-band): 9+ NSB bits.

P=16: (4, 2, 4, 4): ii.i (3bits), ii,2 (3bits), ii.s (2bits), i2 (Ibit per sub-band): 8+ NSB bits.

P=8: (2, 2, 4, 4): ii.i (3bits), ii,2 (3bits), ii.s (2bit), i2 (Ibit per sub-band): 8+ NSB bits.

P=8: (4, 1,4,1): ii.i (4bits), ii, 2 (Obits), ii.s (2bit), i2 (Ibit per sub-band): 6+ NSB bits.

P=4: (2, 1,4,1): ii.i (3bits), ii, 2 (Obits), ii.s (Obit), i2 (Ibit per sub-band): 3+ NSB bits. [0059] In view of this, efficiency of the spatial adaption procedure is stilled required to improve and thus there is provided a solution related to CSI configuration, measurement, and/or reporting to enable efficient spatial adaptation procedure.

[0060] In embodiments of the present disclosure, a terminal device receives a measurement configuration from a network device. The measurement configuration indicates a set of sub-band configurations associated with spatial configurations. The spatial configurations may associate with antenna elements or energy levels of the network device for data transmission or reception, which may or may not be fully visible/visible to the terminal device. The terminal device may perform at least one reference signal measurement based on the measurement configuration. Throughout the description, the terms “measurement configuration”, “report configuration” and “measurement and report configuration” may be used interchangeably unless indicated otherwise.

[0061] The antenna elements may be unmuted or active antenna/spatial elements used for transmission of data or signal. The antenna elements may be muted or inactive antenna/spatial elements not used for transmission of data or signal. It should be noted that the antenna elements may be visible in one implementation, and the antenna elements may not be visible in another implementation. The energy level may be explicitly or implicitly indicated to the terminal device. For example an explicit energy level is configured to the terminal device, or the energy level is implicitly indicated by an order (or position) in a list of configurations.

[0062] The proposed solution may provide efficient CSI feedback with respect to the terminal device’s selection of spatial configurations, and in some embodiments the CSI feedback may adapt the CSI measurement and reporting, for an antenna muting pattern, based on the number of antenna ports.

[0063] As used herein, the term “spatial configuration” may refer to or correspond to at least one pattern of spatial elements, such as antenna elements, transceiver units, antenna ports, antenna panels, for data/signal/control transmission and reception. The term “spatial configuration” may also be referred to as or correspond to a “spatial pattern”. Different spatial configurations may or may not have different numbers of antenna elements, or may use different sets of antenna elements for data transmission and reception.

[0064] In embodiments of the present disclosure, a spatial configuration may correspond to, for example, one or more of: a codebook configuration; a number or a set of antenna ports; a codebook subset restriction (CBSR); a rank restriction; an amplitude restriction; information indicative of a number or a set/subset of active/unmuted antenna or spatial elements; information indicative of a number or a subset of inactive/muted antenna or spatial elements; an energy/power consumption level; an energy/power saving level; or a spatial/antenna muting pattern(s) (one or more such patterns).

[0065] Hereinafter, principle and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Reference is first made to FIG. 1, which illustrates an example environment 100 in which example embodiments of the present disclosure can be implemented.

[0066] The environment 100, which may be a part of a communication network, comprises a terminal device 110 and a network device 120 communicating with each other or with other devices via each other. The communication environment 100 may comprise any suitable number of devices and cells. In the communication environment 100, the terminal device 110 and the network device 120 can communicate data and control information with each other. A link from the network device 120 to the terminal device 110 is referred to as a downlink (DL), while a link from the terminal device 110 to the network device 120 is referred to as an uplink (UL).

[0067] It is to be understood that two devices are shown in the environment 100 only for the purpose of illustration, without suggesting any limitation to the scope of the present disclosure. In some example embodiments, the environment 100 may comprise a further device to communicate with the terminal device 110 and network device 120.

[0068] The communications in the environment 100 may follow any suitable communication standards or protocols, which are already in existence or to be developed in the future, such as universal mobile telecommunications System (UMTS), long term evolution (LTE), LTE- Advanced (LTE-A), the fifth generation (5G) new radio (NR), wireless fidelity (Wi-Fi) and worldwide interoperability for microwave access (WiMAX) standards, and employs any suitable communication technologies, including, for example, multipleinput multiple-output (MIMO), orthogonal frequency division multiplexing (OFDM), time division multiplexing (TDM), frequency division multiplexing (FDM), code division multiplexing (CDM), Bluetooth, ZigBee, and machine type communication (MTC), enhanced mobile broadband (eMBB), massive machine type communication (mMTC), ultrareliable low latency communication (URLLC), carrier aggregation (CA), dual connectivity (DC), and new radio unlicensed (NR-U) technologies. [0069] In embodiments of the present disclosure, the network device 120 transmits to the terminal device 110, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations. Each of the spatial configurations may associate with an energy level or antenna elements. The terminal device 110 receives the measurement configuration from the network device 120. When the CSI report configuration is triggered, the terminal device 110 may perform at least one reference signal measurement based on the measurement configuration. The terminal device 110 may reports the measurement of the spatial configurations and associated sub-band configurations to the network device 120.

[0070] For illustrative purposes, reference will be made to FIG. 2 to describe example spatial configurations in embodiments of the present disclosure.

[0071] FIG. 2 illustrates example spatial configurations with different numbers of active/unmuted antenna or spatial elements. As shown, the elements in the grey boxes are muted or inactive. The spatial configurations or patterns 1-6 have different numbers of active/unmuted antenna or spatial elements, and thus may be regarded as having different power/energy saving levels or consumption levels. The network device 120 may select one or more antenna port (i.e. active ports) and active/unmute the corresponding antenna or spatial elements for data transmission or reception.

[0072] The spatial configurations may have energy levels of the network device for data transmission or reception, respectively, since they may correspond to different numbers of antenna or spatial elements. When the number of antenna ports is reduced, a beam pattern from lower number of antenna ports may be widen due to a low spatial resolution. The wider beam may increase the number of multi-paths, and it may result in a higher delay spread. The High delay spread is reflected as frequency selectivity in channel. Thus, when the number of active antenna ports, P, is smaller, it is beneficial to configure more number of sub-bands for PMI reporting.

[0073] FIG. 3 illustrates an example flowchart of a method 300 implemented at a terminal device according to example embodiments of the present disclosure. For the purpose of discussion, the method 200 will be described from the perspective of the terminal device 110 with reference to FIG. 1 and FIG. 2.

[0074] As shown in FIG. 3, at 310, the terminal device 110 receives, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations. Each of the spatial pattern configurations may associate with an energy level or antenna elements.

[0075] In some embodiments, the each of the spatial configurations may comprise or correspond to, or be replaced by one or more of the following: a codebook configuration; a number or a set of antenna ports; a codebook subset restriction (CBSR); a rank restriction; an amplitude restriction; information indicative of a number of active/unmuted antenna or spatial elements; information indicative of a number of inactive/muted antenna or spatial elements; an energy/power consumption level; an energy/power saving level; or a spatial/antenna muting pattern(s).

[0076] The measurement configuration may be comprised in or correspond to any of a CSI report setting, a CSI report configuration, a spatial configuration, a CSI resource setting, a CSI resource configuration, or a CSI triggering state.

[0077] The association between spatial configurations and sub-band configurations may be configured and indicated to the terminal device 110 in an RRC signal. Additionally or alternatively, such association may be configured and indicated to the terminal device 110 in a medium access control element (MAC CE) or downlink control information (DCI), for example, in form of codepoint or a bitmap, through new or existing entries/bits/fields, such as via the MAC CE or DCI triggering CSI report setting(s)/configuration(s).

[0078] In some embodiments, the measurement configuration may be, for example, a CSI report setting/configuration (or even CSI resource setting). The CSI report setting/configuration (or even CSI resource setting) may include or be associated with multiple sub-band configurations. Each of the sub-band configurations may be associated with at least one codebook or spatial configurations. This may be achieved based on one or more of the following:

• A set of sub-band configurations may be configured within a CSI report setting/configuration and each of the above multiple sub-band configurations may be a subset of this set.

• A list of sub-band configurations may be included in the CSI report configuration, and each is then associated or mapped to at least one codebook or spatial configuration. Alternatively, a sub-band configuration may be included in each codebook or spatial configuration. [0079] In some embodiments, the association between sub-band configurations and spatial configurations may be configured or indicated to the UE via an RRC signaling. Alternatively, or additionally, such association may be indicated/provided to the UE via MAC CE or DCI (e.g., in form of a codepoint or a bitmap), through new or existing entries/bits/fields. For example, the MAC CE or DCI may be that triggering the CSI report setting(s)/configuration(s).

[0080] In some embodiments, this indication may at least comprise a selection of sub-band configurations to consider various (active) codebook or spatial configurations for at least one CSI report setting/configuration (or measurement/report configuration). The terminal device 110 would then map or associate these sub-band configurations to the different active/activated codebook or spatial configurations based on some rule, such as based on increasing/decreasing order of the configuration indexes.

[0081] An example of possible approaches on how to define the mapping between spatial configurations and sub-band configurations may be as below:

• A set/li st of candidate sub-band configurations is defined or configured, using which the sub-band configuration for each spatial configuration is indicated, e.g. via MAC CE or DCI (such as MAC CE or DCI triggering the CSI report, e.g. using some bitmap). Instead of using an indication, the terminal device 110 may alternatively select the sub-band configurations based on a rule such as using the first N sub-band configurations in the set/list, where N is the number of spatial configurations; or using increasing order/decreasing order of indexes for sub-band configurations and spatial configurations.

• This set/list of candidate sub-band configurations may be defined under the CSI report configuration , under a CSI resource setting, or etc..

[0082] Another example of possible approaches on how to define the mapping between spatial configurations and sub-band configurations may be as below:

• The mapping/association is defined solely based on an RRC configuration. When a CSI report setting/configuration is triggered, the terminal device would know the mapping between spatial configurations and sub-band configurations for this report setting/configuration.

[0083] In some embodiments, as a mapping rule, the sub-band configurations may be respectively associated with the spatial configurations based on an increasing order or a decreasing order of the indexes of the sub-band configurations and the indexes of the spatial configurations. In some embodiments, the sub-band configurations may be associated with the spatial configurations in a one-to-one manner, or alternatively, in a one-to-multiple manner or in a multiple-to-one manner. In some embodiments, the set of sub-band configurations are associated with the spatial configurations based on one or more of: indexes of the sub-band configurations; or indexes of the spatial configurations

[0084] FIG. 4A illustrates an example association between spatial configurations and subband configurations. As shown, the CSI report configuration or even the CSI-RS resource setting may contain the measurement configuration. In the CSI report configuration or in the CSR-RS resource setting, the measurement configuration may indicate any of sub-band configurations associated with spatial configurations in a one-to-one manner.

[0085] The sub-band configurations may be associated with the spatial configurations based on indexes of the sub-band configurations and indexes of the spatial configurations in an increasing order. For example, sub-band configuration #0 is associated with spatial configuration #0, sub-band configuration #1 is associated with spatial configuration #1, and so on. Alternatively, the association may be based on a decreasing order. The spatial configuration may be for example a spatial code configuration.

[0086] FIG. 4B illustrates another example association between spatial configurations and sub-band configurations. As shown, the sub-band configurations are associated with the spatial configurations in a one-to-multiple manner. The sub-band configurations are associated with the spatial configurations based on indexes of the sub-band configurations and indexes of the spatial configurations also in an increasing order. Different from FIG. 4A, sub-band configuration #0 is associated with both spatial configurations #0 and #1, and sub-band configuration #1 is associated with both spatial configurations #2 and #3, and so on. As mentioned, the association may also be based on a decreasing order. The spatial configuration may be for example a spatial code configuration.

[0087] Alternatively, the sub-band configurations may also be associated with the spatial configurations in a multiple-to-one manner; in other word, more than one subband configuration may correspond to a spatial configuration.

[0088] It is to be noted that FIG. 4A and FIG. 4B only give two example association approaches and the present disclosure is not limited thereto. Any suitable possible association approach may be applicable in embodiments of the present disclosure. [0089] Referring back to Fig. 3, at 320, the terminal device 110 performs at least one reference signal measurement based on the measurement configuration. The reference signal may comprise CSI-RS. By triggering of CSI report configuration comprising or related to the received measurement configuration, the terminal device 110 may perform measurements based on the subband configuration and the CSI-RS resource or resource set of the configured spatial configurations.

[0090] In some embodiments, the spatial configurations may share a same CSI-RS resource or resource set. The shared CSI-RS resource may be 32-port resource, and each of the spatial configurations may correspond to a subset of the 32-port resource (including 32-port). The number 32 is given here as an example and other numbers are possible such as 24, 16, 8, etc.

[0091] In some embodiments, the terminal device 110 may measure a reference signal for the spatial configurations on associated sub-band configurations. The associated sub-band configurations and the spatial configuration are determined based on the measurement configuration. For example, for measurements and/or reporting of CSI (such as PMI/ RI/ CQI/ SINR etc.), the terminal device 110 may then use, for each of the codebook or spatial configuration, the sub-band configuration corresponding to or associated with the (or respective) codebook or spatial configuration.

[0092] In some embodiments, the sub-band configuration may comprise bitmaps which indicate one or more sub-bands on which the CSI-RS resources or resource sets are transmitted in the frequency domain. As such, the terminal device 110 performs measurements for the spatial configuration considering the bitmap of the associated sub-band configuration.

[0093] The terminal device 110 may further report measurements to the network device 120. In some embodiments, the terminal device 110 may transmit at least one measurement report based on the measurements of the spatial configurations or port subsets and their associated sub-band configurations. The terminal device 110 may be configured to report one or more indexes representing PMI selection per a configured number (such as two) of consecutive sub-bands. This number may be configured via RRC.

[0094] A CSI report setting/configuration, associated with multiple codebook or spatial configurations and/or multiple sub-band configurations, may be split into multiple subreports. Each sub-report may correspond to a codebook or spatial configuration of the multiple codebook or spatial configurations. Alternatively, each sub-report may correspond to a sub-band configuration of the multiple sub-band configurations.

[0095] In some embodiments, the terminal device 110 may transmit at least one measurement report or sub-report based on the reference signal measurement. The terminal device may transmit the multiple measurement reports or sub-reports based on a predetermined reporting priority rule.

[0096] For uplink control information (UCI) dropping/omitting, sub-report priorities or the predetermined reporting priority rule may be defined with respect to, for example, one or more of the following:

• number of sub-bands of sub-reports (for example, a sub-report with a higher number of sub-bands may be given a higher or lower priority)

• codebook or spatial configuration corresponding to sub-reports (for example, based on configuration ID, or based on number of ports, etc.)

[0097] In some embodiments, each of the measurement reports or sub-reports may correspond to at least one sub-band configuration. Alternatively, each of the measurement reports or sub-reports may correspond to at least one spatial configuration.

[0098] In some embodiments, a part of the spatial configurations may correspond to the same number or sets of CSI-RS antenna ports but have different numbers of active spatial elements or different energy levels. In this case, more than one, e.g., two, CSI-RS resources or resource sets (instead of one) may be used. The above operations/proposals may still be valid in this case, and are just defined on per CSI-RS resource level. The use of two CSI- RS resources or resource sets could for example, be for the case where some the spatial configurations (e.g. antenna/spatial muting patterns) have same number/set of antenna ports but different number of antenna elements (turned on/off) or different energy levels.

[0099] Although the focus above has been on CSI report setting/configuration to include or be associated with multiple sub-band configurations, alternatively each of the antenna/spatial muting patterns (i.e., spatial configurations) may be represented by a CSI report sub- setting/sub-configuration. In this case, at least one sub-band configuration would be associated to this CSI report sub-setting/sub-configuration.

[00100] As mentioned above, in embodiments of the present disclosure, a spatial pattern may correspond to, mean or indicate or be indicated different parameters or configurations. In some example embodiments, each of the spatial patterns may correspond to a reference signal resource or a set of reference signal resources. Additionally or alternatively, each of the spatial patterns may correspond to an identifier of a reference signal resource. Additionally or alternatively, each of the spatial patterns may correspond to a number or set of active/unmuted antenna elements or spatial elements. Additionally or alternatively, each of the spatial patterns may correspond to an arrangement of a set of antenna elements or spatial elements. Additionally or alternatively, each of the spatial patterns may correspond to a number or set of antenna ports, a codebook configuration, a spatial configuration, or a report configuration. Additionally or alternatively, each of the spatial patterns may correspond to an energy/power consumption level, or an energy saving level. Additionally or alternatively, each of the spatial patterns may correspond to a priority of reference signal for measurement.

[00101] FIG. 5 illustrates an example flowchart of a method 500 implemented at a terminal device according to example embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the network device 120 with reference to FIG. 1-FIG. 3, FIG. 4 A and FIG. 4B.

[00102] As shown in FIG. 5, at 510, the network device 120 may transmit, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations. Each of the spatial configurations may associate with an energy level or antenna elements. The antenna elements may be unmuted or active antenna/spatial elements used for transmission of data or signal. The antenna elements may be muted or inactive antenna/spatial elements not used for transmission of data or signal. It should be noted that the antenna elements may be visible in one implementation, and the antenna elements may not be visible in another implementation. The energy level may be explicitly or implicitly indicated to the terminal device. For example an explicit energy level is configured to the terminal device, or the energy level is implicitly indicated by an order (or position) in a list of configurations.

[00103] Although the focus has been on sub-band configuration, it should be understood that any of the embodiments may be applicable to all, or at least part of, the ‘frequency domain reporting configuration’. To this end, ‘sub-band configuration’ may be replaced by frequency domain reporting configuration’ or any part of this configuration (other than subband configuration).

[00104] At 520, the network device 120 may receive at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

[00105] In some example embodiments, the network device 120 may provide a configured number indicative of a number of consecutive sub-bands, per which one or more indexes representing PMI selection is reported.

[00106] In some example embodiments, each of the spatial configurations may correspond to one or more of a codebook configuration; a number or a set of antenna ports; a codebook subset restriction, CBSR; a rank restriction; an amplitude restriction; information indicative of a number of active/unmuted antenna or spatial elements; information indicative of a number of inactive/muted antenna or spatial elements; an energy/power consumption level; an energy/power saving level; or a spatial/antenna muting pattern.

[00107] In some example embodiments, the reference signal may comprise CSI-RS, and wherein a same CSI-RS resource or resource set is shared by the spatial configurations.

[00108] In some example embodiments, the sub-band configurations may be associated with the spatial configurations in a one-to-one manner. Alternatively, the sub-band configurations are associated with the spatial configurations in a one-to-multiple manner. Alternatively, the sub-band configurations are associated with the spatial configurations in a multiple-to-one manner.

[00109] In some example embodiments, the measurement configuration may be included in one or more of an RRC signal, a MAC CE, or DCI.

[00110] In some example embodiments, the set of sub-band configurations are associated with the spatial configurations based on one or more of indexes of the sub-band configurations or indexes of the spatial configurations.

[00111] In some example embodiments, the sub-band configurations may be respectively associated with the spatial configurations based on an increasing order or a decreasing order of the indexes of the sub-band configurations and the indexes of the spatial configurations.

[00112] In some example embodiments, the at least one measurement report may comprise multiple measurement reports. The multiple measurement reports may be received based on a predetermined reporting priority rule.

[00113] In some example embodiments, each of the measurement reports may correspond to at least one sub-band configuration. Alternatively, each of the measurement reports may correspond to at least one spatial configuration.

[00114] In some example embodiments, the reference signal may comprise CSI-RS signal. Apart of the spatial configurations corresponds to the same number or sets of CSI-RS antenna ports but have different number of active spatial/antenna elements or different energy levels.

[00115] In some example embodiments, the measurement configuration may be comprised in or correspond to any of a CSI report setting, a CSI report configuration, a spatial configuration, a CSI resource setting, a CSI resource configuration, or a CSI triggering state.

[00116] FIG. 6 illustrates an example signaling process for reporting measurements on reference signals according to some embodiments of the present disclosure. For the purpose of discussion, the process 600 will be described with reference to FIG. 1 to FIG. 5. The process 600 may involve the terminal device 110 and network devices 120 as illustrated in Fig. 1. It would be appreciated that although the process 600 has been described in the communication environment 100 of Fig. 1, this process may be likewise applied to other communication scenarios with similar issues.

[00117] In the process 600, at 601, the network device 120 transmits a measurement configuration 602 to the terminal device 110. At 603, the terminal device 110 receives the measurement configuration 602 from the network device 120. The measurement configuration may indicate a set of sub-band configurations associated with spatial configurations. Each of the spatial configurations may associate with an energy level or antenna elements. The sub-band configurations may include bitmaps which are indicative of configured frequencies resources for the spatial configurations.

[00118] The antenna elements may be unmuted or active antenna/spatial elements used for transmission of data or signal. The antenna elements may be muted or inactive antenna/spatial elements not used for transmission of data or signal. It should be noted that the antenna elements may be visible in one implementation, and the antenna elements may not be visible in another implementation. The energy level may be explicitly or implicitly indicated to the terminal device. For example an explicit energy level is configured to the terminal device, or the energy level is implicitly indicated by an order (or position) in a list of configurations.

[00119] Although the focus has been on sub-band configuration, it should be understood that any of the embodiments may be applicable to all, or at least part of, the ‘frequency domain reporting configuration’. To this end, ‘sub-band configuration’ may be replaced by frequency domain reporting configuration’ or any part of this configuration (other than sub- band configuration).

[00120] The measurement configuration may be comprised or correspond to in any of a CSI report setting; a CSI report configuration; a spatial configuration; a CSI resource setting; a CSI resource configuration; or a CSI triggering state. In some embodiments, the measurement configuration may be included in an RRC signal, a MAC CE or DCI.

[00121] By means of the measurement configuration 602, the terminal device 110 is configured with multiple sub-band configurations for a CSI report configuration/setting, where each sub-band configuration may be associated with or mapped to a spatial configuration.

[00122] At 604, the network device 120 may decide to trigger a CSI report configuration with one CSI-RS resource (e.g. 32-port resource), using which the terminal device 110 may measure CSI-RS with multiple spatial configurations or port subsets.

[00123] The network device 120 then may transmit the CSI-RS resource (e.g. 32-port resource) 605, and the triggering information of the CSI report configuration 606. In some embodiments, the CSI-RS resource 605 may be shared by two or more of the spatial configurations as configured in the measurement configuration 602. The network device 120 may transmit more than one CSI-RS resources, for example, in a case where some spatial configurations or antenna/spatial muting patterns have same number/set of ports but different number of antenna elements (are turned on/off) or different energy levels.

[00124] At 607, the terminal device 110 performs at least one reference signal measurement based on the measurement configuration. In some embodiments, the terminal device may measure a reference signal for the spatial configurations on associated sub-band configurations. The associated sub-band configurations may be determined based on the received measurement configuration.

[00125] At 608, the terminal device 110 may transmit at least one measurement report 609 to the network device 120 based on the reference signal measurement. At 610, the network device 120 may receive the at least one measurement report from the terminal device 110. The at least one measurement report 609 may comprise multiple measurement reports. Each measurement report may correspond to at least one sub-band configuration, or at least one spatial configuration.

[00126] In some embodiments, the terminal device 110 may obtain a configured number indicative of a number of consecutive sub-band, and may report one or more indexes representing PMI selection per the configured number of consecutive sub-band. The number may be configured via RRC signaling.

[00127] In some embodiments, the terminal device 110 may transmit the multiple measurement reports (sub-report) based on a predetermined reporting priority rule. The predetermined reporting priority rule may be defined with respect to the number of the subbands of the measurement reports. For example, a report with a higher number of sub-bands may be given a higher or lower priority. Additionally or alternatively, the priority rule may be defined with respect to the codebook or spatial configuration corresponding to the report, for example, based on configuration ID, or based on number of ports, etc.

[00128] In some embodiments, an apparatus of a terminal device capable of performing the method 300 is provided. The apparatus may comprise means for performing the respective steps of the method 300. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[00129] In some embodiments, the apparatus of the terminal device may comprise means for receiving, from a network device, a measurement configuration which indicates a set of subband configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and means for performing at least one reference signal measurement based on the measurement configuration.

[00130] The antenna elements may be unmuted or active antenna/spatial elements used for transmission of data or signal. The antenna elements may be muted or inactive antenna/spatial elements not used for transmission of data or signal. It should be noted that the antenna elements may be visible in one implementation, and the antenna elements may not be visible in another implementation. The energy level may be explicitly or implicitly indicated to the terminal device. For example an explicit energy level is configured to the terminal device, or the energy level is implicitly indicated by an order (or position) in a list of configurations.

[00131] Although the focus has been on sub-band configuration, it should be understood that any of the embodiments may be applicable to all, or at least part of, the ‘frequency domain reporting configuration’. To this end, ‘sub-band configuration’ may be replaced by frequency domain reporting configuration’ or any part of this configuration (other than subband configuration).

[00132] In some embodiments, means for performing a reference signal measurement based on the measurement configuration may comprises means for measuring a reference signal for the spatial configurations on associated sub-band configurations where the associated subband configurations may be determined based on the measurement configuration.

[00133] In some embodiments, the apparatus may comprise means for obtaining a configured number indicative of a number of consecutive sub-bands, per which one or more indexes representing precoding matrix indicator, PMI selection is reported.

[00134] In some embodiments, each of the spatial configurations may comprise or correspond to one or more of the following: a codebook configuration; a number or a set of antenna ports; a codebook subset restriction, CBSR; a rank restriction; an amplitude restriction; information indicative of a number of active/unmuted antenna or spatial elements; information indicative of a number of inactive/muted antenna or spatial elements; an energy/power consumption level; an energy/power saving level; or a spatial/antenna muting pattern.

[00135] In some embodiments, the reference signal may comprise CSI-RS, and a same CSI- RS resource or resource set is shared by the spatial configurations.

[00136] In some embodiments, the sub-band configurations may be associated with the spatial configurations in a one-to-one manner; the sub-band configurations may be associated with the spatial configurations in a one-to-multiple manner; and/or the sub-band configurations may be associated with the spatial configurations in a multiple-to-one manner.

[00137] In some embodiments, the measurement configuration may be included in one or more of a radio resource control, RRC, signal; a medium access control, MAC, control element, CE; or downlink control information, DCI.

[00138] In some embodiments, the set of sub-band configurations may be associated with the spatial configurations based on one or more of indexes of the sub-band configurations; or indexes of the spatial configurations.

[00139] In some embodiments, the sub-band configurations may be respectively associated with the spatial configurations based on an increasing order or a decreasing order of the indexes of the sub-band configurations and the indexes of the spatial configurations

[00140] In some embodiments, the apparatus may further comprise means for transmitting at least one measurement report based on the reference signal measurement. The at least one measurement report may comprise multiple measurement reports and the multiple measurement reports may be transmitted based on a predetermined reporting priority rule. [00141] In some embodiments, each of the measurement reports may correspond to at least one sub-band configuration, or at least one spatial configuration.

[00142] In some embodiments, the reference signal may comprise CSI-RS signal, and wherein a part of the spatial configurations may correspond to the same number or sets of CSI-RS antenna ports but have different number of active spatial elements or different energy levels.

[00143] In some embodiments, the measurement configuration may be comprised in or correspond to any of: a CSI report setting; a CSI report configuration; a spatial configuration; a CSI resource setting; a CSI resource configuration; or a CSI triggering state.

[00144] In some embodiments, an apparatus of the network device is further provided. The apparatus may comprise means for transmitting, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and means for receiving at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

[00145] The antenna elements may be unmuted or active antenna/spatial elements used for transmission of data or signal. The antenna elements may be muted or inactive antenna/spatial elements not used for transmission of data or signal. It should be noted that the antenna elements may be visible in one implementation, and the antenna elements may not be visible in another implementation. The energy level may be explicitly or implicitly indicated to the terminal device. For example an explicit energy level is configured to the terminal device, or the energy level is implicitly indicated by an order (or position) in a list of configurations.

[00146] Although the focus has been on sub-band configuration, it should be understood that any of the embodiments may be applicable to all, or at least part of, the ‘frequency domain reporting configuration’. To this end, ‘sub-band configuration’ may be replaced by frequency domain reporting configuration’ or any part of this configuration (other than subband configuration).

[00147] In some embodiments, the apparatus of the network device may further comprise means for providing a configured number indicative of a number of consecutive sub-bands, per which one or more indexes representing precoding matrix indicator, PMI selection is reported.

[00148] In some embodiments, each of the spatial configurations may comprise or correspond to one or more of the following: a codebook configuration; a number or a set of antenna ports; a codebook subset restriction, CBSR; a rank restriction; an amplitude restriction; information indicative of a number of active/unmuted antenna or spatial elements; information indicative of a number of inactive/muted antenna or spatial elements; an energy/power consumption level; an energy/power saving level; or a spatial/antenna muting pattern.

[00149] In some embodiments, the reference signal may comprise CSI-RS, and a same CSI- RS resource or resource set is shared by the spatial configurations.

[00150] In some embodiments, the sub-band configurations may be associated with the spatial configurations in a one-to-one manner; the sub-band configurations may be associated with the spatial configurations in a one-to-multiple manner; and/or the sub-band configurations may be associated with the spatial configurations in a multiple-to-one manner.

[00151] In some embodiments, the measurement configuration may be included in one or more of: a radio resource control, RRC, signal; a medium access control, MAC, control element, CE; or downlink control information, DCI.

[00152] In some embodiments, the set of sub-band configurations may be associated with the spatial configurations based on one or more of: indexes of the sub-band configurations; or indexes of the spatial configurations.

[00153] In some embodiments, the sub-band configurations may be respectively associated with the spatial configurations based on an increasing order or a decreasing order of the indexes of the sub-band configurations and the indexes of the spatial configurations

[00154] In some embodiments, the at least one measurement report comprises multiple measurement reports, and the multiple measurement reports are received based on a predetermined reporting priority rule.

[00155] In some embodiments, each of the measurement reports may correspond to at least one sub-band configuration, or at least one spatial configuration.

[00156] In some embodiments, the reference signal may comprise CSI-RS signal, and wherein a part of the spatial configurations may correspond to the same number or sets of CSI-RS antenna ports but have different number of active spatial elements or different energy levels.

[00157] In some embodiments, the measurement configuration may be comprised in or correspond to any of: a CSI report setting; a CSI report configuration; a spatial configuration; a CSI resource setting; a CSI resource configuration; a CSI triggering state.

[00158] The proposed solutions may achieve various advantages over related arts in that it define aspects of CSI reporting framework to enable efficient CSI feedback with respect to the terminal device’s selection of spatial configurations, and in some embodiments may adapt the CSI measurement and reporting, for an antenna muting pattern, based on the number of antenna ports.

[00159] FIG. 7 is a simplified block diagram of a device 700 that is suitable for implementing embodiments of the present disclosure. The device 700 may be provided to implement the communication device, for example the terminal device 110 or the network device 120 as shown in FIG. 1. As shown, the device 700 includes one or more processors 710, one or more memories 740 may be coupled to the processor 710, and one or more transmitters and/or receivers (TX/RX) 740 may be coupled to the processor 710.

[00160] The TX/RX 740 is for bidirectional communications. The TX/RX 740 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements. The communication interface may be hardware or software based interface. For example, the communication interface may be one or more transceivers. The one or more transceivers may be coupled to one or more antennas or antenna ports to wirelessly transmit and/or receive communication signals. The antennas or antenna ports may be the same or different types. The antennas or antenna ports may be located in different positions of an apparatus. The one or more transceivers allow the apparatus to communicate with other devices that may be wired and/or wireless. The transceiver may support one or more radio technologies. For example, the one or more transceivers may include a cellular subsystem, a WLAN subsystem, and/or a Bluetooth™ subsystem. The one or more transceivers may include processors, controllers, radios, sockets, plugs, buffers, or the like circuits to form one or more communication channels to one or more radio frequency units.

[00161] The processor 710 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 700 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.

[00162] The memory 720 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) 724, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 722 and other volatile memories that will not last in the power-down duration.

[00163] A computer program 730 includes computer executable instructions that are executed by the associated processor 710. The program 730 may be stored in the ROM 724. The processor 710 may perform any suitable actions and processing by loading the program 730 into the RAM 722.

[00164] The embodiments of the present disclosure may be implemented by means of the program so that the device 700 may perform any process of the disclosure as discussed with reference to FIG. 3, FIG. 5 and FIG. 6. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[00165] In some embodiments, the program 730 may be tangibly contained in a computer readable medium which may be included in the device 700 (such as in the memory 720) or other storage devices that are accessible by the device 700. The device 700 may load the program 730 from the computer readable medium to the RAM 722 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. FIG. 8 shows an example of the computer readable medium 800 in form of CD or DVD. The computer readable medium has the program 730 stored thereon.

[00166] 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, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While 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.

[00167] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method 300, 400, or process 500 as described above with reference to FIG. 3, FIG. 4 and FIG. 5. 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.

[00168] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes 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 codes, 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.

[00169] In the context of the present disclosure, the computer program codes 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.

[00170] 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. 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).

[00171] Further, while 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, while 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. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

[00172] 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

WHAT IS CLAIMED IS:

1. A terminal device, comprising: one or more transceivers; and one or more processors coupled to the one or more transceivers, wherein the one or more transceivers are configured with the one or more processor to cause the terminal device to: receive, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; perform at least one reference signal measurement based on the measurement configuration.

2. The terminal device of claim 1, wherein the performing a reference signal measurement based on the measurement configuration comprises: measuring a reference signal for the spatial configurations on associated sub-band configurations, where the associated sub-band configurations are determined based on the measurement configuration.

3. The terminal device of claim 1 or 2, wherein the terminal device is further caused to obtain a configured number indicative of a number of consecutive sub-bands, per which one or more indexes representing precoding matrix indicator, PMI selection is reported.

4. The terminal device any of claims 1-3, wherein each of the spatial configurations comprises or corresponds to one or more of the following: a codebook configuration; a number or a set of antenna ports; a codebook subset restriction, CBSR; a rank restriction; an amplitude restriction; information indicative of a number of active/unmuted antenna or spatial elements; information indicative of a number of inactive/muted antenna or spatial elements; an energy/power consumption level; an energy/power saving level; or a spatial/antenna muting pattern.

5. The terminal device of any of claims 1-4, wherein the reference signal comprises CSI-RS, and wherein a same CSI-RS resource or resource set is shared by the spatial configurations.

6. The terminal device of any of claims 1-5, wherein the sub-band configurations are associated with the spatial configurations in a one-to-one manner; and/or wherein the sub-band configurations are associated with the spatial configurations in a one-to-multiple manner; and/or wherein the sub-band configurations are associated with the spatial configurations in a multiple-to-one manner.

7. The terminal device of any of claims 1-6, wherein the measurement configuration is included in one or more of: a radio resource control, RRC, signal; a medium access control, MAC, control element, CE; or downlink control information, DCI.

8. The terminal device of any of claims 1-7, wherein the set of sub-band configurations are associated with the spatial configurations based on one or more of: indexes of the sub-band configurations; or indexes of the spatial configurations.

9. The terminal device of claim 8, wherein the sub-band configurations are respectively associated with the spatial configurations based on an increasing order or a decreasing order of the indexes of the sub-band configurations and the indexes of the spatial configurations

10. The terminal device of any of claims 1-9, wherein the terminal device is further caused to transmit at least one measurement report based on the reference signal measurement, and wherein the at least one measurement report comprises multiple measurement reports and the multiple measurement reports are transmitted based on a predetermined reporting priority rule.

11. The terminal device of claim 10, wherein each of the measurement reports corresponds to at least one sub-band configuration, or at least one spatial configuration.

12. The terminal device of any of claims 1-11, wherein the reference signal comprises CSI-RS signal, and wherein a part of the spatial configurations correspond to the same number or sets of CSI-RS antenna ports but have different numbers of active spatial elements or different energy levels.

13. The terminal device of any of claims 1-12, wherein the measurement configuration is comprised in or corresponds to any of a CSI report setting; a CSI report configuration; a spatial configuration; a CSI resource setting; a CSI resource configuration; or a CSI triggering state.

14. A network device, comprising: one or more transceivers; and one or more processors coupled to the one or more transceivers, and the one or more transceivers are configured with the one or more processor to cause the network device to: transmit, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and receive at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

15. The network device of claim 14, wherein the network device is further caused to: provide a configured number indicative of a number of consecutive sub-bands, per which one or more indexes representing precoding matrix indicator, PMI selection is reported.

16. The network device of claim 14 or 15, wherein each of the spatial configurations comprises or corresponds to one or more of the following: a codebook configuration; a number or a set of antenna ports; a codebook subset restriction, CBSR; a rank restriction; an amplitude restriction; information indicative of a number of active/unmuted antenna or spatial elements; information indicative of a number of inactive/muted antenna or spatial elements; an energy/power consumption level; an energy/power saving level; or a spatial/antenna muting pattern.

17. The network device of any of claims 13-16, wherein the reference signal comprises CSI-RS, and wherein a same CSI-RS resource or resource set is shared by the spatial configurations.

18. The network device of any of claims 13-17, wherein the sub-band configurations are associated with the spatial configurations in a one-to-one manner; and/or wherein the sub-band configurations are associated with the spatial configurations in a one-to-multiple manner; and/or wherein the sub-band configurations are associated with the spatial configurations in a multiple-to-one manner.

19. The network device of any of claims 13-18, wherein the measurement configuration is included in one or more of: an radio resource control, RRC, signal; a medium access control, MAC, control element, CE; or downlink control information, DCI.

20. The network device of any of claims 13-19, wherein the set of sub-band configurations are associated with the spatial configurations based on one or more of: indexes of the sub-band configurations; or indexes of the spatial configurations.

21. The network device of claim 20, wherein the sub-band configurations are respectively associated with the spatial configurations based on an increasing order or a decreasing order of the indexes of the sub-band configurations and the indexes of the spatial configurations.

22. The network device of any of claims 13-21, wherein the at least one measurement report comprises multiple measurement reports; and the multiple measurement reports are received based on a predetermined reporting priority rule.

23. The network device of claim 22, wherein each of the measurement reports corresponds to at least one sub-band configuration, or at least one spatial configuration.

24. The network device of any of claims 13-23, wherein the reference signal comprises CSI-RS signal, and wherein a part of the spatial configurations correspond to the same number or sets of CSI-RS antenna ports but have different number of active spatial elements or different energy levels.

25. The network device of any of claims 13-24, wherein the measurement configuration is comprised in any of a CSI report setting; a CSI report configuration; a spatial configuration; a CSI resource setting; a CSI resource configuration; or a CSI triggering state.

26. A method at a terminal device comprising: receiving, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and performing at least one reference signal measurement based on the measurement configuration.

27. A method at a network device comprising: transmitting, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and receiving at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

28. An apparatus of terminal device comprising: means for receiving, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and means for performing at least one reference signal measurement based on the measurement configuration.

29. An apparatus of network device comprising: means for transmitting, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and means for receiving at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

30. A terminal device, comprising: at least one processor; and at least one memory including computer program codes, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to: receive, from a network device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and perform at least one reference signal measurement based on the measurement configuration.

31. A network device, comprising: at least one processor; and at least one memory including computer program codes, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the network device to: transmit, to a terminal device, a measurement configuration which indicates a set of sub-band configurations associated with spatial configurations, wherein each of the spatial configurations associates with an energy level or antenna elements; and receive at least one measurement report from the terminal device, wherein the measurement report is based on the measurement configuration.

32. A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of claims 26 or 27.