Resource configuration for time and frequency tracking

Abstract

Embodiments of the present disclosure relate to resource configuration for time and frequency tracking In an aspect, a terminal device receives, from a network device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition. The terminal device determines at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

Description

RESOURCE CONFIGURATION FOR TIME AND FREQUENCY TRACKINGCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority from, and the benefit of, US Provisional Application No. 63 / 729627, filed December 9, 2024, which is hereby incorporated by reference in its entirety.FIELD

[0002] Various example embodiments relate to the field of telecommunication and in particular, to a terminal device, a network device, methods, apparatuses and a computer readable medium for resource configuration for time and frequency tracking.BACKGROUND

[0003] A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network.

[0004] Such communication networks operate in accordance with standards, such as those promulgated by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of such standards include the so-called 5G (5th Generation) standard or other standards promulgated by 3GPP.SUMMARY

[0005] In general, example embodiments of the present disclosure provide a solution for resource configuration for time and frequency tracking.

[0006] In a first aspect, there is provided a terminal device. The terminal device comprises at least one processor and at least one memory storing instructions. When executed by the at least one processor, the instructions cause the terminal device at least to: receive, from a network device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and determine at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

[0007] In a second aspect, there is provided a network device. The network device comprises at least one processor and at least one memory storing instructions. When executed by the at least one processor, the instructions cause the network device at least to: transmit, to a terminal device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and determine at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

[0008] In a third aspect, there is provided a terminal device. The terminal device comprises at least one processor and at least one memory storing instructions. When executed by the at least one processor, theinstructions cause the terminal device at least to: receive, from a network device, a configuration for a resource set; and determine at least one first resource for time-and-frequency tracking having a resource element pattern based on the configuration.

[0009] In a fourth aspect, there is provided a network device. The network device comprises at least one processor and at least one memory storing instructions. When executed by the at least one processor, the instructions cause the network device at least to: transmit, to a terminal device, a configuration for a resource set; and determine at least one first resource for time-and-frequency tracking having a resource element pattern based on the configuration.

[0010] In a fifth aspect, there is provided a method performed by a terminal device. The method comprises: receiving, from a network device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and determining at least one first resource for time-and- frequency tracking and at least one second resource for CSI acquisition among the resource set.

[0011] In a sixth aspect, there is provided a method performed by a network device. The method comprises: transmitting, to a terminal device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and determining at least one first resource for time-and- frequency tracking and at least one second resource for CSI acquisition among the resource set.

[0012] In a seventh aspect, there is provided a method performed by a terminal device. The method comprises: receiving, from a network device, a configuration for a resource set; and determining at least one first resource for time-and-frequency tracking having a resource element pattern based on the configuration.

[0013] In an eighth aspect, there is provided a method performed by a network device. The method comprises: transmitting, to a terminal device, a configuration for a resource set; and determining at least one first resource for time-and-frequency tracking having a resource element pattern based on the configuration.

[0014] In a ninth aspect, there is provided an apparatus. The apparatus comprises means for receiving, from a network device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and means for determining at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

[0015] In a tenth aspect, there is provided an apparatus. The apparatus comprises means for transmitting, to a terminal device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and means for determining at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

[0016] In an eleventh aspect, there is provided an apparatus. The apparatus comprises means for receiving, from a network device, a configuration for a resource set; and means for determining at least one first resource for time-and-frequency tracking having a resource element pattern based on the configuration.

[0017] In a twelfth aspect, there is provided an apparatus. The apparatus comprises means for transmitting, to a terminal device, a configuration for a resource set; and means for determining at least one first resourcefor time-and-frequency tracking having a resource element pattern based on the configuration.

[0018] In a thirteenth 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 any one of the above fifth to eighth aspects.

[0019] In a fourteenth aspect, there is provided a computer program product comprising program instructions for performing at least the method according to any one of the above fifth to eighth aspects.

[0020] In a fifteenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to perform at least the method according to any one of the above fifth to eighth aspects.

[0021] 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

[0022] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0023] Fig. 1A illustrates an example communication system in which embodiments of the present disclosure may be implemented;

[0024] Fig. 1 B illustrates an example of non-zero-power channel state information reference signal (NZP- CSI-RS) resource configurations for 48 antenna ports (APs) associated with some embodiments of the present disclosure;

[0025] Fig. 1 C illustrates an example of NZP-CSI-RS resource configurations for 64 APs associated with some embodiments of the present disclosure;

[0026] Fig. 1 D illustrates an example of NZP-CSI-RS resource configurations for 128 APs associated with some embodiments of the present disclosure;

[0027] Fig. 1 E illustrates an example of different TRS configurations associated with some embodiments of the present disclosure;

[0028] Fig. 1 F illustrates an example of NZP-CSI-RS resource configuration for time and frequency tracking associated with some embodiments of the present disclosure;

[0029] Fig. 1G illustrates an example of a NZP-CSI-RS design extended up to 256 APs associated with some embodiments of the present disclosure;

[0030] Fig. 2A illustrates an example signaling chart of a first example process according to some embodiments of the present disclosure;

[0031] Fig. 2B illustrates an example signaling chart of a second example process according to some embodiments of the present disclosure;

[0032] Fig. 3A illustrates a schematic diagram illustrating an example of a joint NZP-CSI-RS resource set configuration of eight 32-AP resources for DL CSI acquisition and four 1-AP resources fortime-and frequency tracking according to some embodiments of the present disclosure;

[0033] Fig. 3B illustrates a schematic diagram illustrating an example of resource element (RE) patterns for eight 32-AP resources for DL CSI acquisition and four 1-AP resources for time-and frequency tracking according to some embodiments of the present disclosure;

[0034] Fig. 4A illustrates a schematic diagram illustrating an example of a joint NZP-CSI-RS resource set configuration of eight 32-AP resources for DL CSI acquisition and four 2-AP resources fortime-and frequency tracking according to some embodiments of the present disclosure;

[0035] Fig. 4B illustrates a schematic diagram illustrating an example of RE patterns for eight 32-AP resources for DL CSI acquisition and four 2-AP resources for time-and frequency tracking according to some embodiments of the present disclosure;

[0036] Fig. 5A illustrates a schematic diagram illustrating an example of a joint NZP-CSI-RS resource set configuration of eight 32-AP resources for DL CSI acquisition and eight 4-AP resources for time-and frequency tracking according to some embodiments of the present disclosure;

[0037] Fig. 5B illustrates a schematic diagram illustrating an example of RE patterns for eight 32-AP resources for DL CSI acquisition and eight 4-AP resources fortime-and frequency tracking according to some embodiments of the present disclosure;

[0038] Fig. 6 illustrates a schematic diagram illustrating a method implemented at a terminal device according to some embodiments of the present disclosure;

[0039] Fig. 7 illustrates a schematic diagram illustrating a method implemented at a network device according to some embodiments of the present disclosure;

[0040] Fig. 8 illustrates a schematic diagram illustrating a method implemented at a terminal device according to some embodiments of the present disclosure;

[0041] Fig. 9 illustrates a schematic diagram illustrating a method implemented at a network device according to some embodiments of the present disclosure;

[0042] Fig. 10 illustrates a simplified block diagram of an apparatus that is suitable for implementing embodiments of the present disclosure; and

[0043] Fig. 11 illustrates a block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

[0044] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0045] Principles 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 illustrationand 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0050] 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 phoneor 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.

[0051] 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.

[0052] 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-loT) 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 first generation (1 G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), the future sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0053] 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 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.

[0054] 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 terminaldevices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehiclemounted 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.

[0055] Principles 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 A, which illustrates an example communication system 100 in which embodiments of the present disclosure may be implemented. As shown in Fig. 1A, the environment 100, which may be a part of a communication network, comprises a terminal device 110 and a network device. The network device 120 may be a gNB, or a NetWork (NW) or a TRP, which schedules a first bandwidth part (BWP) or a first cell 130. The terminal device 110 is capable of connecting and communicating in an UL or DL with the network device 120 as long as the terminal device 110 is located within the corresponding cells (e.g., the first cell 130) of the network device 120.

[0056] In communication systems, an UL refers to a link in a direction from a terminal device 110 to a network device 120, and a DL refers to a link in a direction from the network device 120 to the terminal device 110. The network device 120 may transmit scheduling information scheduling an uplink transmission to the terminal device 110, and the terminal device 110 may transmit a uplink transmission or a plurality of repetitions of the uplink transmission to the network device 120.

[0057] Communications in the communication system 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1 G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G) and the sixth generation (6G) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0058] It is to be understood that the numbers of devices (i.e., the terminal device 110 and the network device 120) and their connection relationships and types shown in Fig. 1A are only for the purpose ofillustration without suggesting any limitation. For example, the communication system 100 may include any suitable numbers of devices adapted for implementing embodiments of the present disclosure. For example, while Fig. 1A depicts the terminal device 110 as a mobile phone, the terminal device 110 may be any types of user equipment.

[0059] Current Release (Rel) 18 NR specification supports up to 32 ports for a CSI-RS resource, which is a bottleneck for deployment of large antenna arrays. It is proposed that Rel-19 Multiple-Input Multiple-Output (MIMO) work item (Wl) will support to increase the port number up to 128, but there is no specification support from 32 to 128 antenna ports per single NZP-CSI-RS resource. By leveraging existing NZP-CSI-RS design with e.g. 24, 32 antenna ports, some typical port numbers that may be considered, e.g., 48, 64,128 by aggregating multiple resources. Considering difference on possible deployment scenarios and gNB antenna implementations, all those port numbers may be considered.

[0060] Regarding the support of NZP-CSI-RS configurations for higher number of antenna ports, for the Rel-19 Type-I and Type-ll codebook refinement for 48, 64, and 128 CSI-RS ports, regarding NZP CSI-RS resource aggregation to attain 32 < P (or PCSI-RS) 128, it has been proposed to support the following refinements on the K>1 CSI-RS resources associated with a same CSI-RS resource set:• Allow per-resource configuration of evenPRBs or oddPRBs for 0.5 RE / RB / port density• For AP-CSI-RS, allow resource-specific slot offset when the K NZP CSI-RS resources are located in two consecutive slots.

[0061] The details on how to configure / determine the slot offsets is to be further studied.

[0062] In other words, within a NZP-CSI-RS resource set, multiple NZP-CSI-RS resources may be aggregated to support 48, 64 and 128 APs, where NZP-CSI-RS resources share the same starting physical resource block (PRB) and each resource within the resource set may be configured either to even PRB or odd PRBs with 0.5 RE / PRB / port density.

[0063] Regarding the support of NZP-CSI-RS configurations for higher number of antenna ports, for the Rel-19 Type-I and Type-ll codebook refinement for 48, 64, and 128 CSI-RS ports, regarding aggregation of K NZP CSI-RS resources to attain 32 < P (or PCSI-RS) 128, it has been proposed to support only the following combinations of K and P (or PCSI-RS):• For P (or PCSI-RS) = 48, K = 2 (each resource 24 ports) and 3 (each resource 16 ports)• For P (or PCSI-RS) = 64, K = 2 (each resource 32 ports) and 4 (each resource 16 ports)• For P (or PCSI-RS) = 128, K = 4 (each resource 32 ports)

[0064] Figs. 1 B-1 D illustrate examples of NZP-CSI-RS resource configurations for 48 APs, 64 APs or 128 APs associated with some embodiments of the present disclosure, respectively. The support for antenna ports up to 128 APs may be obtained by aggregation of different number of NZP-CSI-RS resources. As shown in Fig. 1 B, two resources each associated with 24 APs may be aggregated to attain 48 APs, or three resources each associated with 16 APs may be aggregated to attain 48 APs. As shown in Fig. 1 C, tworesources each associated with 32 APs may be aggregated to attain 64 APs, or four resources each associated with 16 APs may be aggregated to attain 64 APs. As shown in Fig. 1 D, four resources each associated with 32 ports may be aggregated to attain 128 APs.

[0065] For 6G, to support higher spectral efficiencies (e.g. enhanced multi-user (MU) MIMO) and enhanced the coverage in both UL and DL, even larger antenna arrays need to be supported with larger number of physical antenna elements and corresponding logical antenna ports, e.g. up to 256 or 512 logical antenna ports. As a result of this, DL NZP-CSI-RS resource configurations need to support even higher number of antenna ports (>128 APs) with 6G carrier frequencies (e.g., 6.425-7.125 GHz and / or 7.125 -15 GHz).

[0066] NR provides support to set the channel estimator parameters properly for the reception of the demodulation reference signal (DMRS) of physical dedicated control channel (PDCCH), DMRS of physical dedicated data channel (PDSCH) and NZP-CSI-RS by configuring the UE with periodic time and the NZP- CSI-RS based time and frequency TRS in NR. The TRS is a UE specific signal and basically mandatory periodic reference signal to be transmitted for each connected mode UE. The network may share the same configuration to multiple UEs with a service area (e.g. a cell / sector).

[0067] The TRS enables the UE to perform the optimization of different parameters related to a channel estimator, e.g. for DMRS the length of 2-D Wiener filter in a frequency and time. The TRS may be configured by using one or two NZP-CSI-RS resource set with two or four one antenna port NZP-CSI-RS resources with the following parameters. For FR1 , a TRS burst length may be two consecutive valid downlink slots and for FR2, the TRS burst length may be one or two consecutive valid downlink slots. In each TRS slot, there are two TRS symbols. TRS symbols in the slot are having four symbol separation in time. TRS burst periodicity can be either 10, 20, 40 or 80 ms. Fig. 1 E illustrates an example of different TRS configurations associated with some embodiments of the present disclosure. Different TRS configuration options for FR1 and FR2 supported by NR are illustrated. As shown in Fig. 1 E, a notation of {4,8} defines a pair of TRS symbols located in the 4th and 8th symbol positions in a slot.

[0068] The UE may be configured with multiple TRS configurations to receive the TRS and keep tracking time and frequency domain parameters for the channel estimators, e.g. from different transmission points (TRP) / TX beams according to associated TCI state.

[0069] The TRS may periodical and UE specific. In other words, the TRS may configured separately for each UE. There may be additional aperiodic TRS but it has to be always associated with a periodical TRS.

[0070] A UE configured with NZP-CSI-RS-ResourceSet(s) configured with higher layer parameter trs-info may have the CSI-RS resources configured as:Periodic, with the CSI-RS resources in the NZP-CSI-RS-ResourceSet configured with same periodicity, bandwidth and subcarrier location.Periodic CSI-RS resource in one set and aperiodic CSI-RS resources in a second set, with the aperiodicCSI-RS and periodic CSI-RS resource having the same bandwidth (with same RB location) and the aperiodic CSI-RS being configured with qcl-Type set to 'typeA' and 'typeD', where applicable, with the periodic CSI-RS resources.

[0071] The example embodiments of the present disclosure are related to 3GPP 6G physical layer design, and focus on facilitating support for a joint configuration of 6G time-and frequency tracking reference signal and NZP CSI-RS with a large number of APs (e.g. >128 APs).

[0072] Fig. 1 F illustrates an example of NZP-CSI-RS resource configuration for time and frequency tracking associated with some embodiments of the present disclosure. For simplicity, only one physical resource block (PRB) is shown in Fig. 1 F. In the example of Fig. 1 F, one NZP-CSI-RS resource set is configured with ‘trs-info’ and four periodic NZP-CSI-RS resources with a single port associated with a comb- 4 type of resource element pattern where time density associated with two resources is four per slot. The TRS is typically configured to be UE specific. To reduce reference signal resource overhead, the network may share same configuration with multiple UEs within a service area (e.g. a cell / sector). Furthermore, the TRS may also be configured as an aperiodic one but with a restriction to be configured jointly with periodic one. As a result, the number of TRS resources per cell may become large leading to a high reference signal resource overhead, especially, when operating with beam based operation, e.g. FR2 or at new frequency range 7-15 GHz.

[0073] Fig. 1G illustrates an example of a NZP-CSI-RS design extended up to 256 APs associated with some embodiments of the present disclosure. In the example shown in Fig. 1 G, the extended Rel-19 NZP- CSI-RS design (e.g. for 6G) up to 256 APs has 8 NZP-CSI-RS resources each resource associated with 32 APs with CDM-4 (FD-CDM2 and TD-CDM2) and with an antenna port density 0.5 RE / PRB / port density over two consecutive time slots. This resource configuration follows “Row 17” in Table 7.4.1.5.3-1 (CSI-RS locations within a slot) in Technical Specification (TS) 38.211. The maximum number of antenna ports per resource is specified as 32. In the Rel-19 NZP-CSI-RS design up to 128-APs, NZP-CSI-RS resources up to 32-APs for DL CSI acquisition are assumed to be configured such that a network may share same NZP- CSI-RS resource configuration with multiple UEs associated with a specific time type, e.g. aperiodic / semi- persistent / periodic, within a service area (e.g. cell / sector)

[0074] When two separate NZP-CSI-RS resource set configurations for time-and frequency tracking and DL CSI acquisition with high number of antenna ports (>128) are configured with separate frequency and time resources, a resource utilization of the system becomes inefficient leading to problems related to increased latencies, resource overhead, extensive control signaling, etc..

[0075] To enhance this in 6G, it would be highly important to enable a NZP-CSI-RS resource set configuration where time-and frequency tracking and DL CSI acquisition could be done with a single resource configuration.

[0076] In view of the above, embodiments of the present disclosure provide a scheme to support a singleresource configuration for 6G MIMO time-and frequency tracking and DL CSI acquisition. Embodiments of the present disclosure will be described in detail with reference to Figs. 2A to 5B below.

[0077] Fig. 2A illustrates a signaling chart illustrating a first example process 200A according to some embodiments of the present disclosure. For the purpose of discussion, the process 200A will be described with reference to Fig. 1 A. The process 200A may involve the terminal device 110 and the network device 120. It would be appreciated that although the process 200A has been described in the communication environment 100 of Fig. 1A, this process may be likewise applied to other communication scenarios.

[0078] As shown in Fig. 2A, the network device 120 transmits (211), to the terminal device 110, an indication 212 that a resource set is for time-and-frequency tracking and CSI acquisition. The terminal device 110 receives (213) the indication 212 from the network device 120 and determines (214) at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition from the resource set. Similarly, the network device 120 determines (215) the at least one first resource for time- and-frequency tracking and the at least one second resource for CSI acquisition from the resource set. In this way, a joint resource set configuration for both time-and frequency tracking and DL acquisition purposes may be defined. Thus, the resource utilization efficiency may be improved. In addition, the resource overhead and the communication latency may be reduced.

[0079] In some embodiments, the indication 212 may be indicated by a first value of a parameter. A second value of the parameter may be indicative that a resource set is for CSI acquisition. In some implementations, the parameter may be carried in an information element (IE) indicating whether a resource set is jointly configured for time-and-frequency tracking and CSI acquisition. In a more specific example, a higher layer parameter, e.g., 6G-joint-CSI-TRS, may be designed to indicate that resources within the resource set may be used for both DL-CSI acquisition and time-and tracking purposes. For example, when the parameter 6G-joi nt-CS I -TRS is set to ‘TRUE’, the terminal device 110 may assume that part of resources in this resource set is configured for DL CSI acquisition purpose and another part is configured for time-and- tracking purpose. When the parameter 6G-joint-CSI-TRS is set to ‘None’, the terminal device 110 may assume that all resources in this resource set are configured only for DL CSI acquisition purposes. In this way, an IE is designed to indicate a resource set to have both resources for DL CSI acquisition and resources for time and frequency tracking within same resource set.

[0080] In some implementations, the parameter may be carried in tracking reference signal information. In other words, an existing IE (e.g., Trs-info) may be repurposed for indicating resources to be used for DL CSI acquisition and time-and frequency tracking. For example, the higher layer parameter Trs-info may be re-purposed and set to ‘CSI+TRS’ to indicate for the terminal device 110 that a part of the NZP-CSI-RS resource set contains resources for DL CSI acquisition and another part of the NZP-CSI-RS resource set contains resources for time-and frequency tracking. A third value of the parameter may be indicative that a resource set is for time-and-frequency tracking. In this way, an existing IE may be enhanced to indicate aresource set to have both resources for DL CSI acquisition and resources for time and frequency tracking within same resource set.

[0081] In a more specific example, upon reception of the NZP-CSI-RS resource configuration with the higher layer parameter trs-info set to ‘CSI+TRS’, the terminal device 110 may assume that the single NZP- CSI-RS resource set contains one subset of NZP-CSI-RS resources for DL CSI acquisition and another subset of NZP-CSI-RS resources for time-and-frequency tracking. When the parameter trs-info is set to ‘TRS’, the terminal device 110 may assume that all resources in this resource set are configured for time- and-tracking purpose. When the parameter trs-info is set to ‘None’, the terminal device 110 may assume that no resources are configured in this resource set for time-and-tracking purpose, and the terminal device 110 may assume that all resources in this resource set are configured for CSI acquisition. In one implementation example, a RRC configuration of the NZP-CSI-RS resource set definition and related information elements may be provided as follows:- ASN1 START- TAG-NZP-CSI-RS-RESOURCESET-STARTNZP-CSI-RS-ResourceSet ::= SEQUENCE { nzp-CSI-ResourceSetld NZP-CSI-RS-ResourceSet\d, -void text- trs-info ENUMERATED {TRS, CSI+TRS, None}-void text-- TAG-NZP-CSI-RS-RESOURCESET-STOP- ASN1 STOP

[0082] In some example implementations, the resource set may include a subset of M different N-AP NZP- CSI-RS resources (in total M x N antenna ports) for DL CSI-CSI acquisition purpose and a subset of K different L-AP NZP-CSI-RS resources (in total K x L antenna ports) for time-and frequency tracking purpose. All M different NZP-CSI-RS resources for DL CSI-CSI acquisition purpose are configured with N antenna ports. All K different NZP-CSI-RS resources for time-and frequency tracking purpose are configured with L antenna ports. In some embodiments, the terminal device 110 may receive a number (e.g., L) of antenna ports per resource of the at least one first resource from the network device 120. Alternatively or additionally, the terminal device 110 may receive a number (e.g., N) of antenna ports per resource of the at least one second resource from the network device 120. Alternatively or additionally, the terminal device 110 may receive a number (e.g., K) of resources among the at least one first resource from the network device 120. Alternatively or additionally, the terminal device 110 may receive a number (e.g., M) of resources among the at least one second resource. The terminal device 110 may distinguish the resources associated with DL CSI acquisition and the resources associated with time-and-frequency tracking from each other.

[0083] I n some embodiments, the at least one first resource and the at least one second resource may bedetermined based on a number of antenna ports per resource of resources among the resource set. In other words, the terminal device 110 may distinguish resources associated with DL CSI acquisition and resources associated with time-and-frequency tracking according to the number of antenna ports per resource. In some implementations, a number of antenna ports per resource of the at least one first resource is lower than a number of antenna ports per resource of the at least one second resource. In other words, a higher number of antenna ports per resource is always configured for DL CSI acquisition resources compared for time-and-frequency tracking resources, i.e. N>L.

[0084] For example, based on the parameter trs-info set to ‘CSI+TRS’, the terminal device 110 may determine that there is one subset of resources for DL CSI acquisition each with N antenna ports and another subset of NZP-CSI-RS resources acquisition with L antenna ports, such that condition N >L is valid.

[0085] I n some embodiments, the at least one first resource and the at least one second resource may be determined based on identities (IDs) of resources among the resource set. In other words, the terminal device 110 may distinguish resources associated with DL CSI acquisition and resources associated with time-and-frequency tracking according to the resource ID order, where all resource IDs in NZP-CSI-RS resource set are ordered in ascending / descending manner.

[0086] In some implementations, at least one resource ID of the at least one first resource is larger than at least one resource ID of the at least one second resource. For example, all resource IDs in NZP-CSI- RS resource set are ordered in an ascending manner, and the first M ordered IDs of CSI-RS resources are associated with DL CSI acquisition while the remaining (M+K)-M ordered IDs of CSI-RS resources are associated with time-and frequency tracking. In an alternative example, all resource IDs in NZP-CSI-RS resource set are ordered in a descending manner, and the first K ordered IDs of CSI-RS resources are associated with time-and frequency tracking while the remaining (M+K)-K ordered IDs of CSI-RS resources are associated with DL CSI acquisition.

[0087] In some implementations, the at least one first resource and the at least one second resource may be determined based on a predefined rule for an order of resource IDs for time-and-frequency tracking and resource IDs for CSI acquisition. For example, the predefine rule may be that resource IDs for time-and- frequency tracking are larger than resource IDs for CSI acquisition. In some alternative implementations, the terminal device 110 may receive, from the network device 120, an indication that resource IDs for time- and-frequency tracking are larger than resource IDs for CSI acquisition.

[0088] In some embodiments, at least one resource ID of the at least one first resource is smaller than at least one resource ID of the at least one second resource. For example, all resource IDs in NZP-CSI-RS resource set are ordered in an ascending manner, and the first K ordered IDs of CSI-RS resources are associated with time-and frequency tracking while the remaining (M+K)-K ordered IDs of CSI-RS resources are associated with DL CSI acquisition. In an alternative example, all resource IDs in NZP-CSI-RS resource set are ordered in a descending manner, and the first M ordered IDs of CSI-RS resources are associatedwith DL CSI acquisition while the remaining (M+K)-M ordered IDs of CSI-RS resources are associated with time-and frequency tracking.

[0089] In some implementations, the at least one first resource and the at least one second resource may be determined based on a predefined rule for an order of resource IDs for time-and-frequency tracking and resource IDs for CSI acquisition. For example, the predefine rule may be that resource IDs for time-and- frequency tracking are smaller than resource IDs for CSI acquisition. In some alternative implementations, the terminal device 110 may receive, from the network device 120, an indication that resource IDs for time- and-frequency tracking are smaller than resource IDs for CSI acquisition.

[0090] Fig. 2B illustrates a signaling chart illustrating a second example process 200B according to some embodiments of the present disclosure. For the purpose of discussion, the process 200B will be described with reference to Fig. 1 A. The process 200B may involve the terminal device 110 and the network device 120. It would be appreciated that although the process 200B has been described in the communication environment 100 of Fig. 1A, this process may be likewise applied to other communication scenarios. The process 200B may be performed in combination with the process 200A in Fig. 2A or may be performed independently with the processes 200A and 200B.

[0091] As shown in Fig. 2B, the network device 120 transmits (221), to the terminal device 110, a configuration 222 for a resource set. The terminal device 110 receives (223) the configuration 222 from the network device 120 and determines (224) at least one first resource for time-and-frequency tracking having a resource element pattern based on the configuration. Similarly, the network device 120 determines (225) the at least one first resource for time-and-frequency tracking having the resource element pattern. In this way, a resource element pattern for resources of time-and frequency tracking may be designed, thus enabling a joint resource set configuration for both time-and frequency tracking and DL acquisition purposes. Thus, the resource utilization efficiency may be improved. In addition, the resource overhead and the communication latency may be reduced.

[0092] In some embodiments, the resource element pattern for time-and-frequency tracking may be associated with a signal antenna port resource with an antenna port density of four per physical resource block (PRB). In other words, a first resource for time-and-frequency tracking may be a L-AP NZP-CSI-RS resource with an antenna port density 4 per PRB where L=1. A first resource for time-and-frequency tracking is associated with one antenna port and four resource elements (REs) are occupied by the antenna port in one PRB.

[0093] In some embodiments, the resource element pattern for time-and-frequency tracking may be associated with at least one antenna port with an antenna port density of four per PRB. In other words, a first resource for time-and-frequency tracking may be a L-AP NZP-CSI-RS resource with an antenna port density 4 per PRB. A first resource for time-and-frequency tracking is associated with at least one antenna port and four REs are occupied by each antenna port in one PRB. In some implementations, the at least oneantenna port is multiplexed in a time division multiple (TDM) manner. In some implementations, the at least one antenna port may include two antenna ports or four antenna ports. In other words, different antenna ports may be multiplexed in TDM manner over one or more symbols. To enable a joint NZP-CSI-RS resource set configuration of time-and frequency tracking and DL CSI acquisition resources, the time domain multiplexing method for antenna ports of NZP-CSI-RS resource for time-and frequency tracking may be defined as that L different antenna ports of the resource are multiplexed in time domain over consecutive / non- consecutive symbols. For example, when 4-AP NZP-CSI-RS resource is configured with TDMed antenna ports, four different antenna ports are divided over four consecutive / non-consecutive symbols in time.

[0094] In some embodiments, the resource element pattern for time-and-frequency tracking may be associated with two antenna ports with an antenna port density of two per PRB. In other words, a first resource for time-and-frequency tracking may be a 2-AP NZP-CSI-RS resource with an antenna port density 2 per PRB. A first resource for time-and-frequency tracking is associated with two antenna ports and two REs are occupied by each antenna port in one PRB. In some implementations, the two antenna ports with the antenna port density of two per PRB are multiplexed in a code division multiple (CDM) manner. In other words, the two antenna ports associated with one first resource for time-and-frequency tracking are mapped with two REs with a CDM manner, e.g. orthogonal cover code (OCC), i.e. frequency division - CDM 2 (FD- CDM2).

[0095] In some embodiments, the resource element pattern for time-and-frequency tracking may be associated with four antenna ports with an antenna port density of two per PRB. In other words, a first resource for time-and-frequency tracking may be a 4-AP NZP-CSI-RS resource with an antenna port density 2 per PRB. A first resource for time-and-frequency tracking is associated with four antenna ports and two REs are occupied by each antenna port in one PRB. In some implementations, the four antenna ports with the antenna port density of two per PRB are multiplexed in a CDM manner. In a more specific example, the four antenna ports associated with the resource are multiplexed by using FD-CDM2 over two REs and time division - CDM 2 (TD-CDM2) over two consecutive symbols. In other words, all four antenna ports associated with one first resource for time-and-frequency tracking are mapped with two REs and two consecutive symbols sharing same RE locations in frequency with CDM manner, i.e. CDM-4, by using FD- CDM2 over two REs and TD-CDM2 over two consecutive symbols.

[0096] In this way, resource element patterns for NZP-CSI-RS resources of time-and frequency tracking may be defined, e.g., (1) a resource element pattern of a 1-AP NZP-CSI-RS resource with an antenna port density 4 per PRB, (2) a resource element pattern of a L-AP NZP-CSI-RS resource with an antenna port density 4 per PRB, where L different antenna ports are multiplexed in a TDM manner over L symbols (e.g., L=1 , 2, 3 or 4); (3) a resource element pattern of a 2-AP NZP-CSI-RS resource with an antenna port density 2 per PRB, where both antenna ports are mapped with two resource elements with code division multiplexing (CDM) manner, e.g. orthogonal cover code (OCC), i.e., FD-CDM2; (4) a resource element pattern of a 4-APNZP-CSI-RS resource with an antenna port density 2 per PRB, where all four antenna ports are mapped with two resource elements and two consecutive symbols sharing same RE locations in frequency with CDM manner, i.e. CDM-4, by using FD-CDM2 over two resource elements and TD-CDM2 over two consecutive symbols.

[0097] In some embodiments, the resource element pattern for time-and-frequency tracking may be a first resource element pattern. The terminal device may determine at least one second resource for CSI acquisition having a second resource element pattern based on the configuration. In some implementations, the second resource element pattern of the resources for CSI acquisition may be implemented as CSI-RS locations in Table 7.4.1.5.3-1 of TS 38.211. Alternatively or additionally, the second resource element pattern for CSI acquisition may be associated with a signal antenna port resource with an antenna port density of four per physical resource block (PRB). Alternatively or additionally, the second resource element pattern for CSI acquisition may be associated with at least one antenna port with an antenna port density of four per PRB. In some implementations, the at least one antenna port is multiplexed in a TDM manner. In some implementations, the at least one antenna port may include two antenna ports or four antenna ports. Alternatively or additionally, the second resource element pattern for CSI acquisition may be associated with two antenna ports with an antenna port density of two per PRB. In some implementations, the two antenna ports with the antenna port density of two per PRB are multiplexed in a CDM manner. Alternatively or additionally, the second resource element pattern for CSI acquisition may be associated with four antenna ports with an antenna port density of two per PRB. In some implementations, the four antenna ports with the antenna port density of two per PRB are multiplexed in a CDM manner. In a more specific example, the four antenna ports associated with the resource are multiplexed by using FD-CDM2 over two REs and TD-CDM2 over two consecutive symbols.

[0098] In this way, additional resource element patterns for NZP-CSI-RS resources of CSI acquisition may be defined, e.g., (1) a resource element pattern of a 1-AP NZP-CSI-RS resource with an antenna port density 4 per PRB, (2) a resource element pattern of a L-AP NZP-CSI-RS resource with an antenna port density 4 per PRB, where L different antenna ports are multiplexed in a TDM manner over L symbols (e.g., L=1 , 2, 3 or 4); (3) a resource element pattern of a 2-AP NZP-CSI-RS resource with an antenna port density 2 per PRB, where both antenna ports are mapped with two resource elements with code division multiplexing (CDM) manner, e.g. orthogonal cover code (OCC), i.e., FD-CDM2; (4) a resource element pattern of a 4-AP NZP- CSI-RS resource with an antenna port density 2 per PRB, where all four antenna ports are mapped with two resource elements and two consecutive symbols sharing same RE locations in frequency with CDM manner, i.e. CDM-4, by using FD-CDM2 over two resource elements and TD-CDM2 over two consecutive symbols.

[0099] In some embodiments, the configuration for the resource set may include a placement indication of the resource element pattern for time-and-frequency tracking. In an example implementation, the placement indication may be carried in a 12-bit bitmap.

[0100] Alternatively or additionally, the configuration for the resource set may include a placement indication of the second resource element pattern for CSI acquisition. In an example implementation, the placement indication of the second resource element pattern may be carried in a 12-bit bitmap.

[0101] For example, to enable a joint NZP-CSI-RS resource set configuration of time-and frequency tracking and DL CSI acquisition resources, an information element associated with NZP-CSI-RS resource mapping may be defined as that each NZP-CSI-RS resource is configured with an information element enabling to adjust a resource element pattern placement at a resource element granularity. In a more specific example, a NZP-CSI-RS resource mapping may be configured with 6G-ResourcePatternPlacement = ‘110011001100’, where the left most 2 bits (MSB) define Res (RE index 0, and RE index 1 within a PRB) associated with antenna port group x, Res (RE index 4, and RE index 5 within a PRB) associated with antenna port group y, and Res (RE index 8, and RE index 9 within a PRB) associated with antenna port group z. It should be understood that the term “6G-ResourcePatternPlacement" is merely illustrated as an example for the information element, other terms are also possible, e.g., Mapping6G- ResourcePattemPlacement. In one implementation example, an implementation example of a RRC configuration of NZP-CSI-RS resource mapping definition and related information elements may be provided as follows:- ASN1 START- TAG-CSI-RS-RESOURCEMAPPING-START CSI-RS-ResourceMapping ::= SEQUENCE { -void text— frequencyDomainAllocation CHOICE { row1 BIT STRING (SIZE (4)), row2 BIT STRING (SIZE (12)), row4 BIT STRING (SIZE (3)), other BIT STRING (SIZE (6)) 6G-ResourcePatternPlacement BIT STRING (SIZE (12)) }, -void text— } - TAG-CSI-RS-RESOURCEMAPPING-STOP - ASN1 STOP

[0102] Table 1 shows an example of a 6G extension of NZP-CSI-RS resources with TDMed antenna ports up to four. This configuration may be applicable for joint TRS and CSI acquisition resource set configuration. Table 1 may be an extension of Table 7.4.1.5.3-1 in TS 38.211.Table 2 Extension of CSI-RS locations within a slot with for time-and frequency tracking resources

[0103] Fig. 3A illustrates a schematic diagram illustrating an example of a joint NZP-CSI-RS resource set configuration of eight 32-AP resources for DL CSI acquisition and four 1-AP resources fortime-and frequency tracking according to some embodiments of the present disclosure. As shown in Fig. 3A, a joint NZP-CSI- RS resource set #1 is configured for DL CSI acquisition with eight different 32-AP NZP-CSI-RS resources (i.e., M=8, and N=32, in total 256 antenna ports) and for time-and frequency tracking with four different 1-AP antenna port resources (i.e., K=4, L=1 ).

[0104] Fig. 3B illustrates a schematic diagram illustrating an example of RE patterns for eight 32-AP resources for DL CSI acquisition and four 1 -AP resources for time-and frequency tracking according to some embodiments of the present disclosure. In the sharing single NZP-CSI-RS resource configuration with 8 different 32-antenna port NZP-CSI-RS resources for DL CSI acquisition and 4 different 1-AP NZP-CSI-RS resources for time-and frequency tracking, a resource element pattern for each 1-AP NZP-CSI-RS resource for time-and frequency tracking may have an antenna port density 4 per PRB. The 6G- ResourcePatternPlacement BIT STRING (SIZE (12)) for each resource for TRS is 100100100100. The 6G-ResourcePatternPlacement BIT STRING (SIZE (12)) for each resource for DL CSI acquisition is 011011011011.

[0105] For time-and frequency tracking, the UE first computes antenna port specific channel estimates over four symbols. Then, the UE computes phase difference between antenna port specific channel estimates and corresponding antenna port pairs associated with two symbols. Here, dashed lines with arrowsindicate antenna port pairs (i.e. with the same antenna port ID). After this, the UE sums up all antenna port pair phase differences and computes single phase difference value based on which frequency offset value is computed. Finally, the UE shall compensate the computed phase / frequency offset from upcoming DL DMRS PDSCH and PDSCH transmissions as well as all UL PUSCH DMRS, PUSCH transmissions. For DL CSI acquisition, according to configured CSI report, the UE shall compute antenna port specific channel estimates for all 256 antenna ports over two consecutive time slots as well as corresponding reported CSI parameters (e.g. for type-1 PMI, Rl, CQI).

[0106] Fig. 4A illustrates a schematic diagram illustrating an example of a joint NZP-CSI-RS resource set configuration of eight 32-AP resources for DL CSI acquisition and four 2-AP resources fortime-and frequency tracking according to some embodiments of the present disclosure. As shown in Fig. 4A, a joint NZP-CSI- RS resource set #1 is configured for DL CSI acquisition with eight different 32-AP NZP-CSI-RS resources (i.e., M=8, and N=32, in total 256 antenna ports) and for time-and frequency tracking with four different 2-AP antenna port resources (i.e., K=4, L=2).

[0107] Fig. 4B illustrates a schematic diagram illustrating an example of RE patterns for eight 32-AP resources for DL CSI acquisition and four 2-AP resources for time-and frequency tracking according to some embodiments of the present disclosure. In the sharing single NZP-CSI-RS resource configuration with 8 different 32-AP resources for DL CSI acquisition and 4 different 2-antenna port resources with TDMed antenna ports for time-and frequency tracking, a resource element pattern for each 2-AP NZP-CSI-RS resource for time-and frequency tracking may have an antenna port density 4 per PRB, and two different antenna ports are multiplexed in a TDM manner over two symbols. The dashed lines with arrows indicate antenna port pairs (i.e. with the same antenna port ID). The 6G-ResourcePatternPlacement BIT STRING (SIZE (12)) for each resource forTRS is 100100100100. The 6G-ResourcePatternPlacement BIT STRING (SIZE (12)) for each resource for DL CSI acquisition is 011011011011 .

[0108] Fig. 5A illustrates a schematic diagram illustrating an example of a joint NZP-CSI-RS resource set configuration of eight 32-AP resources for DL CSI acquisition and eight 4-AP resources for time-and frequency tracking according to some embodiments of the present disclosure. As shown in Fig. 5A, a joint NZP-CSI-RS resource set #1 is configured for DL CSI acquisition with eight different 32-AP NZP-CSI-RS resources (i.e., M=8, and N=32, in total 256 antenna ports) and for time-and frequency tracking with four different 4-AP antenna port resources (i.e., K=4, L=4).

[0109] Fig. 5B illustrates a schematic diagram illustrating an example of RE patterns for eight 32-AP resources for DL CSI acquisition and eight 4-AP resources fortime-and frequency tracking according to some embodiments of the present disclosure. In the sharing single NZP-CSI-RS resource configuration with 8 different 32-AP resources for DL CSI acquisition and 8 different 4-antenna port resources with TDMed antenna ports for time-and frequency tracking, a resource element pattern for each 4-AP NZP-CSI-RS resource for time-and frequency tracking may have an antenna port density 2 per PRB, and four differentantenna ports are multiplexed in a CDM manner, i.e., FD-CDM2 over two REs and TD-CDM2 over two consecutive symbols. The dashed lines with arrows indicate antenna port pairs (i.e. with the same antenna port ID). The 6G-ResourcePatternPlacement BIT STRING (SIZE (12)) for each resource for TRS is 001100110000. The 6G-ResourcePatternPlacement BIT STRING (SIZE (12)) for each resource for DL CSI acquisition is 110011001111.

[0110] With some embodiments of the present disclosure, a joint resource configuration for time-and frequency tracking and DL CSI acquisition enables to utilize frequency and time resource allocations configured for DL CSI acquisition also for time-and frequency tracking purposes more efficiently. The overall system operation is simplified such that a network may configure the UE with a single cell-specific NZP-CSI resource set configuration which consist of resources for time-and frequency tracking as well as DL CSI acquisition. Similarly, the network may trigger aperiodic resources for time-and frequency tracking and DL CSI acquisition with one information field leading to reduction in DL control signaling overhead. Due to more efficient usage of frequency and resources, latencies associated with time-and frequency channel tracking as well as DL CSI acquisition may be reduced. As a result of the enhanced resource utilization, the overall system performance (for both the venders and the users) may be improved.

[0111] Fig. 6 illustrates a schematic diagram illustrating a method 600 implemented at a terminal device according to some embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the terminal device 110 as shown in Fig. 1A.

[0112] As shown in Fig. 6, at block 610, the terminal device 110 receives, from a network device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition. At block 620, the terminal device 110 determines at least one first resource for time-and- frequency tracking and at least one second resource for CSI acquisition among the resource set.

[0113] In some embodiments, the indication is indicated by a first value of a parameter. A second value of the parameter is indicative that a resource set is for CSI acquisition.

[0114] In some embodiments, the parameter is carried in an information element indicating whether a resource set is jointly configured for time-and-frequency tracking and CSI acquisition.

[0115] In some embodiments, the parameter is carried in tracking reference signal information, and a third value of the parameter is indicative that a resource set is for time-and-frequency tracking.

[0116] In some embodiments, the at least one first resource and the at least one second resource are determined based on a number of antenna ports per resource of resources among the resource set.

[0117] In some embodiments, a number of antenna ports per resource of the at least one first resource is lower than a number of antenna ports per resource of the at least one second resource.

[0118] In some embodiments, the at least one first resource and the at least one second resource are determined based on identities (IDs) of resources among the resource set.

[0119] In some embodiments, at least one resource ID of the at least one first resource is larger than atleast one resource ID of the at least one second resource. Alternatively, at least one resource ID of the at least one first resource is smaller than at least one resource ID of the at least one second resource.

[0120] In some embodiments, the at least one first resource and the at least one second resource are determined based on a predefined rule for an order of resource IDs for time-and-frequency tracking and resource IDs for CSI acquisition.

[0121] In some embodiments, the terminal device may receive, from the network device, an indication that resource IDs for time-and-frequency tracking are larger than resource IDs for CSI acquisition. Alternatively, the terminal device may receive, from the network device, an indication that resource IDs for time-and- frequency tracking are smaller than resource IDs for CSI acquisition.

[0122] In some embodiments, the terminal device may receive, from the network device, a number of antenna ports per resource of the at least one first resource. Alternatively or additionally, the terminal device may receive, from the network device, a number of antenna ports per resource of the at least one second resource. Alternatively or additionally, the terminal device may receive, from the network device, a number of resources among the at least one first resource. Alternatively or additionally, the terminal device may receive, from the network device, a number of resources among the at least one second resource.

[0123] Fig. 7 illustrates a schematic diagram illustrating a method 700 implemented at a network device according to some embodiments of the present disclosure. For the purpose of discussion, the method 700 will be described from the perspective of the network device 120 as shown in Fig. 1A.

[0124] As shown in Fig. 7, at block 710, the network device 120 transmits, to a terminal device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition. At block 720, the network device 120 determines at least one first resource for time-and- frequency tracking and at least one second resource for CSI acquisition among the resource set.

[0125] In some embodiments, the indication is indicated by a first value of a parameter. A second value of the parameter is indicative that a resource set is for CSI acquisition.

[0126] In some embodiments, the parameter is carried in an information element indicating whether a resource set is jointly configured for time-and-frequency tracking and CSI acquisition.

[0127] In some embodiments, the parameter is carried in tracking reference signal information, and a third value of the parameter is indicative that a resource set is for time-and-frequency tracking.

[0128] In some embodiments, the at least one first resource and the at least one second resource are determined based on a number of antenna ports per resource of resources among the resource set.

[0129] In some embodiments, a number of antenna ports per resource of the at least one first resource is lower than a number of antenna ports per resource of the at least one second resource.

[0130] In some embodiments, the at least one first resource and the at least one second resource are determined based on identities (IDs) of resources among the resource set.

[0131] In some embodiments, at least one resource ID of the at least one first resource is larger than atleast one resource ID of the at least one second resource. Alternatively, at least one resource ID of the at least one first resource is smaller than at least one resource ID of the at least one second resource.

[0132] In some embodiments, the at least one first resource and the at least one second resource are determined based on a predefined rule for an order of resource IDs for time-and-frequency tracking and resource IDs for CSI acquisition.

[0133] In some embodiments, the network device may transmit, to the terminal device, an indication that resource IDs for time-and-frequency tracking are larger than resource IDs for CSI acquisition. Alternatively, the network device may transmit, to the terminal device, an indication that resource IDs for time-and- frequency tracking are smaller than resource IDs for CSI acquisition.

[0134] In some embodiments, the network device may transmit, to the terminal device, a number of antenna ports per resource of the at least one first resource. Alternatively or additionally, the network device may transmit, to the terminal device, a number of antenna ports per resource of the at least one second resource. Alternatively or additionally, the network device may transmit, to the terminal device, a number of resources among the at least one first resource. Alternatively or additionally, the network device may transmit, to the terminal device, a number of resources among the at least one second resource.

[0135] Fig. 8 illustrates a schematic diagram illustrating a method 800 implemented at a terminal device according to some embodiments of the present disclosure. For the purpose of discussion, the method 800 will be described from the perspective of the terminal device 110 as shown in Fig. 1A.

[0136] As shown in Fig. 8, at block 810, the terminal device 110 receives, from a network device, a configuration for a resource set. At block 820, the terminal device 110 determines at least one first resource for time-and-frequency tracking having a resource element pattern based on the configuration.

[0137] In some embodiments, the resource element pattern is associated with one of the following: a signal antenna port with an antenna port density of four per physical resource block (PRB); at least one antenna port with an antenna port density of four per PRB; two antenna ports with an antenna port density of two per PRB; or four antenna ports with an antenna port density of two per PRB.

[0138] In some embodiments, the resource element pattern is a first resource element pattern. The terminal device may determine at least one second resource for channel status information (CSI) acquisition having a second resource element pattern based on the configuration.

[0139] In some embodiments, the second resource element pattern is associated with one of the following: a signal antenna port with an antenna port density of four per physical resource block (PRB); at least one antenna port with an antenna port density of four per PRB; two antenna ports with an antenna port density of two per PRB; or four antenna ports with an antenna port density of two per PRB.

[0140] In some embodiments, the at least one antenna port is multiplexed in a time division multiple (TDM) manner. In some embodiments, the at least one antenna port comprises two antenna ports or four antenna ports.

[0141] In some embodiments, the two antenna ports with the antenna port density of two per PRB are multiplexed in a code division multiple (CDM) manner.

[0142] In some embodiments, the four antenna ports with the antenna port density of two per PRB are multiplexed in a CDM manner. In some embodiments, the four antenna ports are multiplexed by using frequency division - CDM 2 (FD-CDM2) for over two resource elements and time division - CDM 2 (TD-CDM2) over two consecutive symbols.

[0143] In some embodiments, the configuration for the resource set comprises a placement indication of the resource element pattern. In some embodiments, the placement indication is carried in a 12-bit bitmap.

[0144] In some embodiments, the configuration for the resource set comprises a placement indication of the second resource element pattern. In some embodiments, the placement indication of the second resource element pattern is carried in a 12-bit bitmap.

[0145] Fig. 9 illustrates a schematic diagram illustrating a method 900 implemented at a network device according to some embodiments of the present disclosure. For the purpose of discussion, the method 900 will be described from the perspective of the network device 120 as shown in Fig. 1A.

[0146] As shown in Fig. 9, at block 910, the network device 120 transmits, to a terminal device, a configuration for a resource set. At block 920, the network device 120 determines at least one first resource for time-and-frequency tracking having a resource element pattern based on the configuration.

[0147] In some embodiments, the resource element pattern is associated with one of the following: a signal antenna port with an antenna port density of four per physical resource block (PRB); at least one antenna port with an antenna port density of four per PRB; two antenna ports with an antenna port density of two per PRB; or four antenna ports with an antenna port density of two per PRB.

[0148] In some embodiments, the resource element pattern is a first resource element pattern. The network device determines at least one second resource for channel status information (CSI) acquisition having a second resource element pattern based on the configuration.

[0149] In some embodiments, the second resource element pattern is associated with one of the following: a signal antenna port with an antenna port density of four per physical resource block (PRB); at least one antenna port with an antenna port density of four per PRB; two antenna ports with an antenna port density of two per PRB; or four antenna ports with an antenna port density of two per PRB.

[0150] In some embodiments, the at least one antenna port is multiplexed in a time division multiple (TDM) manner. In some embodiments, the at least one antenna port comprises two antenna ports or four antenna ports.

[0151] In some embodiments, the two antenna ports with the antenna port density of two per PRB are multiplexed in a code division multiple (CDM) manner.

[0152] In some embodiments, the four antenna ports with the antenna port density of two per PRB are multiplexed in a CDM manner. In some embodiments, the four antenna ports are multiplexed by usingfrequency division - CDM 2 (FD-CDM2) for over two resource elements and time division - CDM 2 (TD-CDM2) over two consecutive symbols.

[0153] In some embodiments, the configuration for the resource set comprises a placement indication of the resource element pattern. In some embodiments, the placement indication is carried in a 12-bit bitmap.

[0154] In some embodiments, the configuration for the resource set comprises a placement indication of the second resource element pattern. In some embodiments, the placement indication of the second resource element pattern is carried in a 12-bit bitmap.

[0155] In some embodiments, an apparatus capable of performing any of the method 600 (for example, the terminal device 110) may comprise means for performing the respective steps of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0156] In some embodiments, the apparatus may include: means for receiving, from a network device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and means for determining at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

[0157] In some embodiments, the indication is indicated by a first value of a parameter. A second value of the parameter is indicative that a resource set is for CSI acquisition.

[0158] In some embodiments, the parameter is carried in an information element indicating whether a resource set is jointly configured for time-and-frequency tracking and CSI acquisition.

[0159] In some embodiments, the parameter is carried in tracking reference signal information, and a third value of the parameter is indicative that a resource set is for time-and-frequency tracking.

[0160] In some embodiments, the at least one first resource and the at least one second resource are determined based on a number of antenna ports per resource of resources among the resource set.

[0161] In some embodiments, a number of antenna ports per resource of the at least one first resource is lower than a number of antenna ports per resource of the at least one second resource.

[0162] In some embodiments, the at least one first resource and the at least one second resource are determined based on identities (IDs) of resources among the resource set.

[0163] In some embodiments, at least one resource ID of the at least one first resource is larger than at least one resource ID of the at least one second resource. Alternatively, at least one resource ID of the at least one first resource is smaller than at least one resource ID of the at least one second resource.

[0164] In some embodiments, the at least one first resource and the at least one second resource are determined based on a predefined rule for an order of resource IDs for time-and-frequency tracking and resource IDs for CSI acquisition.

[0165] In some embodiments, the apparatus may further include means for receiving, from the network device, an indication that resource IDs for time-and-frequency tracking are larger than resource IDs for CSIacquisition. Alternatively, the apparatus may further include means for receiving, from the network device, an indication that resource IDs for time-and-frequency tracking are smaller than resource IDs for CSI acquisition.

[0166] In some embodiments, the apparatus may further include means for receiving, from the network device, at least one of the following a number of antenna ports per resource of the at least one first resource; a number of antenna ports per resource of the at least one second resource; a number of resources among the at least one first resource; or a number of resources among the at least one second resource.

[0167] In some embodiments, the apparatus further may include means for performing other steps in some embodiments of the method 600. In some embodiments, the means may include at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0168] In some embodiments, an apparatus capable of performing any of the method 700 (for example, the network device 120) may comprise means for performing the respective steps of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0169] In some embodiments, the apparatus may include: means for transmitting, to a terminal device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and means for determining at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

[0170] In some embodiments, the indication is indicated by a first value of a parameter. A second value of the parameter is indicative that a resource set is for CSI acquisition.

[0171] In some embodiments, the parameter is carried in an information element indicating whether a resource set is jointly configured for time-and-frequency tracking and CSI acquisition.

[0172] In some embodiments, the parameter is carried in tracking reference signal information, and a third value of the parameter is indicative that a resource set is for time-and-frequency tracking.

[0173] In some embodiments, the at least one first resource and the at least one second resource are determined based on a number of antenna ports per resource of resources among the resource set.

[0174] In some embodiments, a number of antenna ports per resource of the at least one first resource is lower than a number of antenna ports per resource of the at least one second resource.

[0175] In some embodiments, the at least one first resource and the at least one second resource are determined based on identities (IDs) of resources among the resource set.

[0176] In some embodiments, at least one resource ID of the at least one first resource is larger than at least one resource ID of the at least one second resource. Alternatively, at least one resource ID of the at least one first resource is smaller than at least one resource ID of the at least one second resource.

[0177] In some embodiments, the at least one first resource and the at least one second resource aredetermined based on a predefined rule for an order of resource IDs for time-and-frequency tracking and resource IDs for CSI acquisition.

[0178] In some embodiments, the apparatus may further include means for transmitting, to the terminal device, an indication that resource IDs for time-and-frequency tracking are larger than resource IDs for CSI acquisition. Alternatively, the apparatus may further include means for transmitting, to the terminal device, an indication that resource IDs for time-and-frequency tracking are smaller than resource IDs for CSI acquisition.

[0179] In some embodiments, the apparatus may further include means for transmitting, to the terminal device, at least one of the following a number of antenna ports per resource of the at least one first resource; a number of antenna ports per resource of the at least one second resource; a number of resources among the at least one first resource; or a number of resources among the at least one second resource.

[0180] In some embodiments, the apparatus further may include means for performing other steps in some embodiments of the method 700. In some embodiments, the means may include at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0181] In some embodiments, an apparatus capable of performing any of the method 800 (for example, the terminal device 110) may comprise means for performing the respective steps of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0182] In some embodiments, the apparatus may include: means for receiving from a network device, a configuration for a resource set; and means for determining at least one first resource for time-and-frequency tracking having a resource element pattern based on the configuration.

[0183] In some embodiments, the resource element pattern is associated with one of the following: a signal antenna port with an antenna port density of four per physical resource block (PRB); at least one antenna port with an antenna port density of four per PRB; two antenna ports with an antenna port density of two per PRB; or four antenna ports with an antenna port density of two per PRB.

[0184] In some embodiments, the resource element pattern is a first resource element pattern. The apparatus may further include means for determining at least one second resource for channel status information (CSI) acquisition having a second resource element pattern based on the configuration.

[0185] In some embodiments, the second resource element pattern is associated with one of the following: a signal antenna port with an antenna port density of four per physical resource block (PRB); at least one antenna port with an antenna port density of four per PRB; two antenna ports with an antenna port density of two per PRB; or four antenna ports with an antenna port density of two per PRB.

[0186] In some embodiments, the at least one antenna port is multiplexed in a time division multiple (TDM) manner. In some embodiments, the at least one antenna port comprises two antenna ports or four antennaports.

[0187] In some embodiments, the two antenna ports with the antenna port density of two per PRB are multiplexed in a code division multiple (CDM) manner.

[0188] In some embodiments, the four antenna ports with the antenna port density of two per PRB are multiplexed in a CDM manner. In some embodiments, the four antenna ports are multiplexed by using frequency division - CDM 2 (FD-CDM2) for over two resource elements and time division - CDM 2 (TD-CDM2) over two consecutive symbols.

[0189] In some embodiments, the configuration for the resource set comprises a placement indication of the resource element pattern. In some embodiments, the placement indication is carried in a 12-bit bitmap.

[0190] In some embodiments, the configuration for the resource set comprises a placement indication of the second resource element pattern. In some embodiments, the placement indication of the second resource element pattern is carried in a 12-bit bitmap.

[0191] In some embodiments, the apparatus further may include means for performing other steps in some embodiments of the method 800. In some embodiments, the means may include at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0192] In some embodiments, an apparatus capable of performing any of the method 900 (for example, the network device 120) may comprise means for performing the respective steps of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0193] In some embodiments, the apparatus may include: means for transmitting to a terminal device, a configuration for a resource set; and means for determining at least one first resource for time-and-frequency tracking having a resource element pattern based on the configuration.

[0194] In some embodiments, the resource element pattern is associated with one of the following: a signal antenna port with an antenna port density of four per physical resource block (PRB); at least one antenna port with an antenna port density of four per PRB; two antenna ports with an antenna port density of two per PRB; or four antenna ports with an antenna port density of two per PRB.

[0195] In some embodiments, the resource element pattern is a first resource element pattern. The apparatus may further include means for determining at least one second resource for channel status information (CSI) acquisition having a second resource element pattern based on the configuration.

[0196] In some embodiments, the second resource element pattern is associated with one of the following: a signal antenna port with an antenna port density of four per physical resource block (PRB); at least one antenna port with an antenna port density of four per PRB; two antenna ports with an antenna port density of two per PRB; or four antenna ports with an antenna port density of two per PRB.

[0197] In some embodiments, the at least one antenna port is multiplexed in a time division multiple (TDM)manner. In some embodiments, the at least one antenna port comprises two antenna ports or four antenna ports.

[0198] In some embodiments, the two antenna ports with the antenna port density of two per PRB are multiplexed in a code division multiple (CDM) manner.

[0199] In some embodiments, the four antenna ports with the antenna port density of two per PRB are multiplexed in a CDM manner. In some embodiments, the four antenna ports are multiplexed by using frequency division - CDM 2 (FD-CDM2) for over two resource elements and time division - CDM 2 (TD-CDM2) over two consecutive symbols.

[0200] In some embodiments, the configuration for the resource set comprises a placement indication of the resource element pattern. In some embodiments, the placement indication is carried in a 12-bit bitmap.

[0201] In some embodiments, the configuration for the resource set comprises a placement indication of the second resource element pattern. In some embodiments, the placement indication of the second resource element pattern is carried in a 12-bit bitmap.

[0202] In some embodiments, the apparatus further may include means for performing other steps in some embodiments of the method 900. In some embodiments, the means may include at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0203] Fig. 10 is a simplified block diagram of a device 1000 that is suitable for implementing embodiments of the present disclosure. The device 1000 may be provided to implement the communication device, for example the terminal device 110, or the network device 120 as shown in Fig. 1A. As shown, the device 1000 includes one or more processors 1010, one or more memories 1020 coupled to the processor 1010, and one or more communication modules 1040 coupled to the processor 1010.

[0204] The communication module 1040 is for bidirectional communications. The communication module 1040 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

[0205] The processor 1010 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 1000 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.

[0206] The memory 1020 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) 1024, 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) 1022 and other volatilememories that will not last in the power-down duration.

[0207] A computer program 1030 includes computer executable instructions that are executed by the associated processor 1010. The program 1030 may be stored in the ROM 1020. The processor 1010 may perform any suitable actions and processing by loading the program 1030 into the RAM 1020.

[0208] The embodiments of the present disclosure may be implemented by means of the program 1030 so that the device 1000 may perform any process of the disclosure as discussed with reference to Figs. 2A to 13. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0209] In some embodiments, the program 1030 may be tangibly contained in a computer readable medium which may be included in the device 1000 (such as in the memory 1020) or other storage devices that are accessible by the device 1000. The device 1000 may load the program 1030 from the computer readable medium to the RAM 1022 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. 11 shows an example of the computer readable medium 1100 in form of CD or DVD. The computer readable medium has the program 1030 stored thereon.

[0210] 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.

[0211] 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 computerexecutable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out and of the methods, 600, 700, 800 or 900 as described above with reference to Figs. 6-9. 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.

[0212] Program code for carrying out methods of the present disclosure may be written in any combinationof 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.

[0213] 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.

[0214] 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).

[0215] 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.

[0216] 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: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: receive, from a network device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and determine at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

2. The terminal device of claim 1 , wherein the indication is indicated by a first value of a parameter, and wherein a second value of the parameter is indicative that a resource set is for CSI acquisition.

3. The terminal device of claim 2, wherein the parameter is carried in an information element indicating whether a resource set is jointly configured for time-and-frequency tracking and CSI acquisition.

4. The terminal device of claim 2, wherein the parameter is carried in tracking reference signal information, and a third value of the parameter is indicative that a resource set is for time-and-frequency tracking.

5. The terminal device of at least one of claims 1-4, wherein the at least one first resource and the at least one second resource are determined based on a number of antenna ports per resource of resources among the resource set.

6. The terminal device of claim 5, wherein a number of antenna ports per resource of the at least one first resource is lower than a number of antenna ports per resource of the at least one second resource.

7. The terminal device of at least one of claims 1-4, wherein the at least one first resource and the at least one second resource are determined based on identities (IDs) of resources among the resource set.

8. The terminal device of claim 7, wherein at least one resource I D of the at least one first resource is larger than at least one resource ID of the at least one second resource; or wherein at least one resource ID of the at least one first resource is smaller than at least one resourceID of the at least one second resource.

9. The terminal device of claim 7 or 8, wherein the at least one first resource and the at least one second resource are determined based on a predefined rule for an order of resource IDs for time-and- frequency tracking and resource IDs for CSI acquisition.

10. The terminal device of claim 7 or 8, wherein the terminal device is further caused to: receive, from the network device, an indication that resource IDs for time-and-frequency tracking are larger than resource IDs for CSI acquisition; or receive, from the network device, an indication that resource IDs for time-and-frequency tracking are smaller than resource IDs for CSI acquisition.11 . The terminal device of any of claims 1 -10, wherein the terminal device is further caused to: receive, from the network device, at least one of the following: a number of antenna ports per resource of the at least one first resource, a number of antenna ports per resource of the at least one second resource, a number of resources among the at least one first resource, or a number of resources among the at least one second resource.

12. A network device comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: transmit, to a terminal device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and determine at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

13. The network device of claim 12, wherein the indication is indicated by a first value of a parameter, and wherein a second value of the parameter is indicative that a resource set is for CSI acquisition.

14. The network device of claim 13, wherein the parameter is carried in an information element indicating whether a resource set is jointly configured for time-and-frequency tracking and CSI acquisition.

15. The network device of claim 13, wherein the parameter is carried in tracking reference signalinformation, and a third value of the parameter is indicative that a resource set is for time-and-frequency tracking.

16. The network device of at least one of claims 12-15, wherein the at least one first resource and the at least one second resource are determined based on a number of antenna ports per resource of resources among the resource set.

17. The network device of claim 16, wherein a number of antenna ports per resource of the at least one first resource is lower than a number of antenna ports per resource of the at least one second resource.

18. The network device of at least one of claims 12-15, wherein the at least one first resource and the at least one second resource are determined based on identities (IDs) of resources among the resource set.

19. The network device of claim 18, wherein at least one resource ID of the at least one first resource is larger than at least one resource ID of the at least one second resource; or wherein at least one resource ID of the at least one first resource is smaller than at least one resource ID of the at least one second resource.

20. The network device of claim 18 or 19, wherein the at least one first resource and the at least one second resource are determined based on a predefined rule for an order of resource IDs for time-and- frequency tracking and resource IDs for CSI acquisition.21 . The network device of claim 18 or 19, wherein the network device is further caused to: transmit, to the terminal device, an indication that resource IDs for time-and-frequency tracking are larger than resource IDs for CSI acquisition; or transmit, to the terminal device, an indication that resource IDs for time-and-frequency tracking are smaller than resource IDs for CSI acquisition.

22. The network device of any of claims 12-21 , wherein the network device is further caused to transmit, to the terminal device, at least one of the following: a number of antenna ports per resource of the at least one first resource, a number of antenna ports per resource of the at least one second resource, a number of resources among the at least one first resource, or a number of resources among the at least one second resource.

23. A method performed by a terminal device, comprising: receiving, from a network device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and determining at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

24. A method performed by a network device, comprising: transmitting, to a terminal device, an indication that a resource set is for time-and-frequency tracking and channel status information (CSI) acquisition; and determining at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

25. An apparatus comprising: means for receiving, from a network device, an indication that a resource set is for time-and- frequency tracking and channel status information (CSI) acquisition; and means for determining at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

26. An apparatus comprising: means for transmitting, to a terminal device, an indication that a resource set is for time-and- frequency tracking and channel status information (CSI) acquisition; and means for determining at least one first resource for time-and-frequency tracking and at least one second resource for CSI acquisition among the resource set.

27. A computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least one of the methods of claims 23-24.

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