Multi-slot demodulation reference signal

Abstract

Example embodiments of the present disclosure are directed to a solution for DMRS configurations with symmetric time domain separation between different DMRS symbols for multi-slot PDSCH scheduling. A terminal device reports its capability for DMRS channel estimation to a network device. The network device transmits multi-slot scheduling information that is based on the capability for DMRS channel estimation to the terminal device. The terminal device devices a channel estimation filter across antenna port specific channel estimates. In this way, it enables DMRS overhead reduction for PDSCH transmission resulting enhanced PDSCH throughput. Further, it also enhances quality of antenna port specific channel estimates of PDSCH DMRS associated with regular symbol offsets with multiple DMRS symbols.

Description

MULTI-SLOT DEMODULATION REFERENCE SIGNALCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority from, and the benefit of, EP Application No. 25151097.0, filed January 10, 2025, which is hereby incorporated by reference in its entirety.FIELD

[0002] Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices, apparatuses and computer readable storage medium for multi-slot demodulation reference signal (DMRS).BACKGROUND

[0003] Demodulation reference signal (DMRS) is used to assist in channel estimation. It helps a receiver (such as, user equipment (UE)) to estimate a channel quality and compensate for any impairments caused by a wireless channel during the demodulation process. Further, multi-slot scheduling with single grant for multi-physical uplink shared channel (PUSCH) was introduced for control overhead saving for unlicensed operation. Multi-slot scheduling PUSCH was then extended to licensed operation as well as multi-slot scheduling PDSCH to reduce control overhead. In multi-slot scheduling, single transmission block (TB) can span more than one slot in comparison with single slotbased scheduling. This reduces hybrid automatic request (HARQ) feedback as well as saves HARQ process IDs. In general, new radio (NR) multi-slot scheduling can enhance flexibility, efficiency, and performance in resource allocation across multiple slots with respect to single-slot scheduling where resources can be allocated for one slot at a time. Multi-slot scheduling PUSCH can support rank 1 MIMO PUSCH transmission.SUMMARY

[0004] In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: transmit, to a second apparatus, capability information for demodulation reference signal, DMRS, channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multislot scheduling of a plurality of slots.

[0005] In a second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: receive, from a firstapparatus, capability information for demodulation reference signal, DMRS, channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0006] In a third aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: obtain at least one demodulation reference signal, DMRS, configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; and receive, from a second apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

[0007] In a fourth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: determine a target demodulation reference signal, DMRS, configuration from at least one DMRS configuration for multislot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; and transmit, to a first apparatus, an indication indicating the target DMRS configuration.

[0008] In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: determine one or more demodulation reference signal, DMRS, symbol positions within a plurality of slots based on a DMRS configuration; determine a channel estimation filter configuration based on a symbol offset between consecutive DMRS symbols; and obtain an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration.

[0009] In a sixth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, at a first apparatus and to a second apparatus, capability information for demodulation reference signal, DMRS, channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0010] In a seventh aspect of the present disclosure, there is provided a method. The method comprises: receiving, at a second apparatus and from a first apparatus, capability information for demodulation reference signal, DMRS, channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0011] In an eighth aspect of the present disclosure, there is provided a method. The methodcomprises: obtaining, at a first apparatus, at least one demodulation reference signal, DMRS, configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; and receiving, from a second apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

[0012] In a ninth aspect of the present disclosure, there is provided a method. The method comprises: determining a target demodulation reference signal, DMRS, configuration from at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; and transmitting, to a first apparatus, an indication indicating the target DMRS configuration.

[0013] In a tenth aspect of the present disclosure, there is provided a method. The method comprises: determining, at a first apparatus, one or more demodulation reference signal, DMRS, symbol positions within a plurality of slots based on a DMRS configuration; determining a channel estimation filter configuration based on a symbol offset between consecutive DMRS symbols; and obtaining an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration.

[0014] In an eleventh aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for transmitting, to a second apparatus, capability information for demodulation reference signal, DMRS, channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0015] In a twelfth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for receiving, from a first apparatus, capability information for demodulation reference signal, DMRS, channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0016] In a thirteenth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for obtaining at least one demodulation reference signal, DMRS, configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; and means for receiving, from a second apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

[0017] In a fourteenth aspect of the present disclosure, there is provided a second apparatus. Thesecond apparatus comprises means for determining a target demodulation reference signal, DMRS, configuration from at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; and means for transmitting, to a first apparatus, an indication indicating the target DMRS configuration.

[0018] In a fifteenth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for determining one or more demodulation reference signal, DMRS, symbol positions within a plurality of slots based on a DMRS configuration; means for determining a channel estimation filter configuration based on a symbol offset between consecutive DMRS symbols; and means for obtaining an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration.

[0019] In a sixteenth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to one of the sixth, seventh, or eighth aspect.

[0020] In a seventeenth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the ninth or tenth aspect.

[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, where:

[0023] FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0024] FIG. 2 illustrates a schematic diagram of an example of physical downlink shared channel (PDSCH) DMRS type-1 resource element pattern allocation for one physical resource block (PRB);

[0025] FIG. 3 illustrates a schematic diagram of an example of multi-slots PDSCH scheduling with two slots and two DMRS symbols;

[0026] FIG. 4 illustrates a signaling chart for multi-slot DMRS according to some example embodiments of the present disclosure;

[0027] FIG. 5A to FIG. 5C illustrate a schematic diagram of an example PDSCH DMRS channel capability according to some example embodiments of the present disclosure, respectively;

[0028] FIG. 6A illustrates an example of signaling flow diagram scheduling PDSCH DMRS with capability signaling of the maximum regular symbol offset according to some example embodiments of the present disclosure;

[0029] FIG. 6B illustrates an example of signaling flow diagram scheduling PDSCH DMRS with capability signaling of the set of regular symbol offset values according to some example embodiments of the present disclosure;

[0030] FIG. 7 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0031] FIG. 8 illustrates a flowchart of a method implemented at a second apparatus in accordance with some example embodiments of the present disclosure;

[0032] FIG. 9 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0033] FIG. 10 illustrates a flowchart of a method implemented at a second apparatus in accordance with some example embodiments of the present disclosure;

[0034] FIG. 11 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0035] FIG. 12 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0036] FIG. 13 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0037] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0038] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0039] 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.

[0040] 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 particularfeature, 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.

[0041] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0042] 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.

[0043] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0044] 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.

[0045] 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 anapparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0046] 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.

[0047] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), 5.5G, the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0048] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (I AB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. AnIAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

[0049] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0050] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains. The term “channel estimation” refers to a process of determining the characteristics of a communication channel in order to compensate forthe effects of the channel on the transmitted signal.

[0051] FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure can be implemented. In the communication environment 100, a plurality of communication devices, including a terminal device 110 and a network device 120, can communicate with each other. In the example of FIG. 1, the terminal device 110 may be a UE and the network device120 may be a base station serving the UE. The serving area of the network device 120 may be called a cell 102.

[0052] It is to be understood that the number of devices and their connections shown in FIG. 1 are only for the purpose of illustration without suggesting any limitation. The communication environment 100 may include any suitable number of devices configured to implementing example embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additional devices may be located in the cell 102, and one or more additional cells may be deployed in the communication environment 100. It is noted that although illustrated as a network device, the network device 120 may be another device than a network device. Although illustrated as a terminal device, the terminal device 110 may be another device than a terminal device.

[0053] In the following, for the purpose of illustration, some example embodiments are described with the terminal device 110 operating as a UE and the network device 120 operating as a base station. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other device.

[0054] In some example embodiments, a transmission direction from the network device 120 to the terminal device 110 is referred to as a downlink (DL), while a transmission direction from the terminal device 110 to the network device 120 is referred to as an uplink (UL). In DL, the network device 120 is a transmitting (TX) device (or a transmitter) and the terminal device 110 is a receiving (RX) device (or a receiver). In UL, the terminal device 110 is a TX device (or a transmitter) and the network device 120 is a RX device (or a receiver).

[0055] Communications in the communication environment 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols, 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.

[0056] In New Radio (NR), the UE can be configured with physical uplink shared channel (PUSCH) / p hysical downlink shared channel (PDSCH) DMRS which provides support up to 24 antenna ports (APs) for uplink / downlink multi-user MIMO operation. Furthermore, current 5G New Radio(NR) 3GPP physical layer specification provides support for a UE to be configured with one or more DMRS symbols in time within a slot, e.g. up to four symbols. Table 1 which is Table 7.4.1.1.2-3 from technical specification (TS) 38.211 below shows DMRS symbol positions for PDSCH when using PDSCH type A or PDSCH type B mapping. In Table 1, Id represents the number of symbols in slot and Io represents an offset start from the slot.Table 1 PDSCH DM-RS positions / for single-symbol DM-RS Zdin DK 1-RS positions / symbols PDSCH mapping type A PDSCH mapping type B dmrs '-AdditionalP osition dmrs-A dditionalPosi Von posO pos1 pos2 pos3 posO pos1 pos2 pos3 2 - - - - k k ^0 ^0 3 l0l0l0l0lo lo lo lo 4 l0l0l0l0k k lo lo 5 l0l0l0l0lo IQ> 4 IQ> 4 IQ> 4 6 l0l0l0l0'o IQ’ 4 IQ’ 4 7 l0l0l0l0k IQ’ 4 IQ’ 4 8 l0IQ > IQ > IQ > lo Zo, 6 Zo, 3, 6 Zo, 3, 6 9 l0l0, 7 l0, 7 l0, 7 IQ l0, 7 Zo, 4, 7 Zo, 4, 7 10 l0 / 0, 9 i0, 6, 9 i0, 6, 9 IQ l0,7 Zo, 4, 7 Zo, 4, 7 11 l0 / 0, 9 / 0, 6, 9 / 0, 6, 9 IQ l0, Q Zo, 4, 8 Zo, 3, 6, 9 12 l0 / 0, 9 l0, 6, 9 / 0, 5, 8, IQ l0,9 Zo, 5, 9 Zo, 3, 6, 91113 l0 / o. / o, 7, 11 / 0, 5, 8, ^0 l0,9 Zo, 5, 9 Zo, 3, 6, 911 1114 l0 / o. Zo, 7, 11 Zo, 5, 8, - - - -11 110057]Table 2 provides an example of DMRS resource overhead in time domain associated with type-1, type-2, e-type-1 and e-type2 patterns for PDSCH allocation over 11 symbols. As shown, when all DL DMRS antenna ports are indicated for UE(s), DMRS resource overhead in time domain may go up to 36% leading very high DMRS resource overhead in time domain.Table 2 Rel-15 Type-1, Type-2 and Rel-18 e-Type1 and e-Type2 DMRS resource overhead in time per symbol with respect to 11 symbol PDSCH allocationDMRS resource overhead in time [%] over 11 symbols1FL FL+1 FL+2 FL+39,1 18,2 27,3 36,4

[0058] FIG. 2 shows an example of PDSCH DMRS type-1 resource element pattern allocation for one PRB with 1 Front Load (FL) + 3 additional DMRS symbols (2 PDCCH symbols + 1 PUCCH symbol). As discussed previously, multi-slot / PDSCH scheduling can enable enhanced flexibility, efficiency, and performance in resource allocation across multiple slots with respect to single-slot scheduling where resources can be allocated for one slot at a time. Currently, NR supports to use same DMRS configuration for each slot length indicator value (SLIV).

[0059] Table 3 shows an example of DMRS resource overhead in [%] in terms of number of DMRS symbols with different number of scheduled slots associated with single PDSCH transport block (TB). As can be observed, the resource overhead becomes smaller as the number of scheduled slots is increased with single scheduling grant. In other words, multi-slot scheduling can enable higher achievable throughput by reducing the DMRS resource overhead compared with sending the data over separate PDSCHs each with its own dedicated DMRS symbols. Furthermore, it can be observed that up to 10 different DMRS symbols be configured over 4 slots at a reasonable DMRS overhead (< 20%) marked with green color. It is worth noting that current NR specification does not support DMRS configurations where the number of DMRS symbols exceeds four symbols.Table 3 an example of PDSCH DMRS (11 symbols) overhead in [%] in terms of number of DMRS symbols with different number of scheduled slotsOverhead [%] the number The number of DMRS symbolsof slots 1 2 3 4 5 6 7 8 9 10 119,11 18,28 27,37 36,436 45,5 54,55 63,66 72,77 81,88 90,99 100 154 8 12 16 20 24 28 32 36 40 44 22,6 5,1 7,7 2 10,3 12,8 15,4 17,9 20,5 23,1 25,6 28,2 31,9 3,8 5,7 7,5 9,4 11,32075 13,2 15,0 17,0 18,9 20,7 40060] FIG. 3 shows an example of multi-slot PDSCH scheduling with single downlink contro information (DCI) where single PDSCH TB is scheduled over two consecutive times slots with two DMRS symbols which is DMRS type-1. As shown, current NR supports PDSCH DMRS to be transmitted at same symbol locations in both slots (same applies also for multi-slot scheduling with the number of slots larger than 2). Moreover, it can be observed that time separation between two different DMRS symbols is not symmetrical, e.g. time separation between two DMRS symbols in 1stslot (i.e. indices 2 and 10) is 8 symbol and separation between DMRS symbols (index 8) 1st slot and (index 2) is 7 symbol.

[0061] Since different DMRS symbols are not symmetrically distributed across PDSCH allocation in multi-Zsingle slot scheduling, a problem arises for time-domain estimation (e.g. linear, interpolated or higher order non-linear estimator) associated with DMRS antenna port specific channel estimates across different DMRS symbols (frequency domain estimator, for example, Wiener filter or minimum mean square estimation (MMSE) filter is applied on each DMRS symbol). More specifically, time domain asymmetricity of DMRS symbol positions imposes a need for time domain interpolation which does not provide as good channel estimation quality as time-domain estimation as the number of symbols over which the interpolation needs to be done is uneven between DMRS symbols. Moreover, when DMRS symbols do not exist in the end of the allocation, a form of extrapolation might be also needed. In other words, new radio specification is lacking support for PDSCH DMRS configurations which enable efficient utilization of time domain estimation (e.g. with Wiener / MMSE filtering) for multi-slot PDSCH scheduling.

[0062] In accordance with some example embodiments of the present disclosure, there is provided a solution for DMRS configurations with symmetric time domain separation between different DMRS symbols for multi-slot PDSCH scheduling. A terminal device reports its capability for DMRS channel estimation to a network device. The network device transmits multi-slot scheduling information that is based on the capability for DMRS channel estimation to the terminal device. The terminal device devices a channel estimation filter across antenna port specific channel estimates. In this way, it enables DMRS overhead reduction for PDSCH transmission resulting enhanced PDSCH throughput. Further, it also enhances quality of antenna port specific channel estimates of PDSCH DMRS associated with regular symbol offsets with multiple DMRS symbols.

[0063] Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0064] Reference is made to FIG. 4, which illustrates a signaling flow of multi-slot DMRS in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the signaling flow 400 will be discussed with reference to FIG. 1, for example, by using the terminal device 110 and the network device 120.

[0065] The terminal device 110 transmits (4010) capability information for DMRS channel estimation to the network device 120. That is, the network device 120 receives (4010) the capability information for DMRS channel estimation from the terminal device 110. The capability information indicates one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots (such as, a plurality of consecutive slots). In some embodiments, the capability informationmay be transmitted via radio resource control (RRC) signaling. Byway of example, the terminal device 110 may indicate, via capability signaling, its PDSCH DMRS estimator capability for different symbol offset values between different DMRS symbols for multi-slot PDSCH scheduling of L consecutive slots. In this case, L may be any suitable number. In this way, it enables DMRS overhead reduction for PDSCH transmission resulting enhanced PDSCH throughput for 6G.

[0066] In some embodiments, the capability information further indicates one or more other supported symbol offset values between DMRS symbols for multi-slot scheduling of another plurality of consecutive slots. For example, the capability information may indicate a supported symbol offset value between DMRS symbols for multi-slot scheduling of L1 consecutive slots and another supported symbol offset value between DMRS symbols for multi-slot scheduling of L2 consecutive slots. In this case, L1 and L2 may be different integers.

[0067] In some example embodiments, an effective PDSCH allocation time, Tl, refers to PDSCH allocation time in symbols associated with L consecutive slots where PDSCH allocation does not overlap with any other UL / DL control channels or reference signals (RSs) or signals. For example, if L is equal to 2, each slot includes 2 symbols at the beginning and 1 symbol at the end of slot which are reserved for other UL / DL channels / RSs / signals. Alternatively, or in addition, PDSCH allocation time, Tl refers to PDSCH allocation time where different UL / DL control channels or RSs or signals may overlap with PDSCH. In some embodiments, effective PDSCH allocation time, Tl or Tl may be hard coded / pre-defined. Alternatively, the network device 120 may configure effective PDSCH allocation time, Tl or Tl for the terminal device 110.

[0068] In some example embodiments, the capability information indicates a fixed supported symbol offset value between the DMRS symbols for the first number of DMRS symbols within the plurality of consecutive slots. Alternatively, the capability information includes a maximum supported symbol offset value between the DMRS symbols for a first number of DMRS symbols within the plurality of consecutive slots. For example, the terminal device 110 may report its supported maximum symbol offset value for a certain number of DMRS symbols with effective PDSCH allocation time associated with consecutive multi-slot PDSCH scheduling with length of L consecutive slots.

[0069] For example, the capability information may indicate a multi-slot scheduling length specific maximum symbol offset value (represented as Ap^) between different PDSCH DMRS symbols for specific number of DMRS symbols / LMRS. In other words, the DMRS channel estimator can support any DMRS symbol offset value between consecutive DMRS symbols up to the reported maximum symbol offset value, such that consecutive DMRS symbols are regularly distributed in time for effective PDSCH allocation time of L consecutive slots.

[0070] I n some example embodiments, if the plurality of consecutive slots includes 2 slots, the terminaldevice 110 indicates that PDSCH DMRS channel estimator support number of DMRS symbols as well as maximum symbol offset values between DMRS symbols as: L=2:? / LD=^RS= 2, A™MRS=2 =25; i DMRS > 2Amax, L=2 > A.A, DMRS > A max, L=2 > n.A7DMRS >Amax, L=2 > r ^L=2 —DMRS “ 12, A / L=2— 4, ADMRS- 0, A / L=2— 5, ADMRS- 0. For example, in this case, for 3 DMRS symbols, the symbol offset value between DMRS symbols may be any suitable value that is not greater than 12, such as, 4 or 8 or 12.

[0071] Alternatively, or in addition, the terminal device 110 indicates that PDSCH DMRS channel estimator support number of DMRS symbols as well as maximum symbol offset values between DMRS symbols for 3 consecutive slots as: L=3: N™RS= 2, A™^RS=3=39; N™RS= 3, A^RS"3= 19;m3rs= 4, APMRS=3 = 13; <m3rs= 5, A™RS=3=9- For example, in this case, for 3 DMRS symbols, the symbol offset value between DMRS symbols may be any suitable value that is not greater than 19, such as, 10 or 15 or 19.

[0072] In some other example embodiments, if the plurality of consecutive slots includes 4 slots, the terminal device 110 indicates that PDSCH DMRS channel estimator support number of DMRS symbols as well as maximum symbol offset values between DMRS symbols as: L=4: = 2,Amax, L=4 > co. 11DMRS > oAmax, L=4 > no.A, DMRS > AAmax, L=4 >1 7.A, DMRS > r ^DMRS " / VL=4 — ^DMRS “ 20, 7VL=4— 4, ^DMRS “1' ’7VL=4 “b’Amax, L=4 >.t o.ArDMRS > z-Amax, L=4 >A, DMRS > -7Amax, L=4 > n.A, DMRS > o ^DMRS "NL=4 ~ ^DMRS “1 U’NL=4 ~ ' > ^DMRS “ °>NL=4 ~ ^DMRS=4=7:M4RS=9' ^DMRS=4= 6;M4RS= 10, A™XRLS=4= 5. For example, in this case, for 3 DMRS symbols, the symbol offset value between DMRS symbols may be any suitable value that is not greater than 26.

[0073] FIG. 5A shows an example PDSCH DMRS channel estimator capability for the maximum time domain regular separation between symbols for N™RS= 2, with sub-slot specific reserved symbols at start T1R4start=2, TR2Start=0 and end of sub-slots TR End=0, TR2End= 1, andADMRS=2 =Based on these sub-slot specific reserved symbols as well as length of multi-slot scheduling, the terminal device 110 can determine effective PDSCH allocation time. For example, the maximum symbol offset value 520 between the DMRS symbol 510-1 and the DMRS symbol 510-2 may be 14 symbols. As shown in FIG. 5A, for the first sub-slot, the reserved symbols at the start of the first sub-slot include 2 symbols and the reserved symbols at the end of the first sub-slot include 0 symbol. For the second sub-slot, the reserved symbols at the start of the second sub-slot include 0 symbol and the reserved symbols at the end of the second sub-slot include 1 symbol.

[0074] FIG. 5B shows an example of reported PDSCH DMRS channel estimator capability for maximum time domain regular separation between symbols for N™RS= 2, A^RS"2= 23. Specifically, FIG.5B shows an example of PDSCH DMRS channel estimator capability for maximum time domain regular separation between symbols for scheduling length of 2 slots with N™RS= 2 and A™MRS=2= 24.For example, as shown in FIG. 5B, there are DMRS symbols 511-1 and 511-2 within 2 consecutive slots. The maximum symbol offset value 521 between the DMRS symbol 511-1 and the DMRS symbol 511-2 may be 23 symbols. Upon reception of the capability information, the network device 120 may assume that the terminal device 110 can be configured with two PDSCH DMRS symbols with time domain separation in maximum of 23 symbols.

[0075] In some example embodiments, the capability information includes a set of supported symbol offset values between the DMRS symbols for a second number of DMRS symbols within the plurality of consecutive slots. For example, the terminal device 110 reports via capability signaling the set of symbol offset values for a specific number of DMRS symbols (associated with effective PDSCH allocation time with consecutive multi-slot PDSCH scheduling with length of L consecutive slots. In this case, the reported set of symbol offset values may define symbol offsets for a certain number of DMRS symbols and such consecutive DMRS symbols have regular symbol offset between consecutive DMRS symbols.

[0076] I n some example embodiments, if the plurality of consecutive slots includes 2 slots, the terminal device 110 indicates that PDSCH DMRS channel estimator supports a set of three different DMRS symbol offset values for consecutive multi-slot lengths (i.e., 2 slots), which may include WL^RS= 2,ADMRS2 =H 20’ 23; N™RS= 3,= 8,9,11. Alternatively, or in addition, if the plurality of consecutive slots includes 3 slots, the terminal device 110 indicates that PDSCH DMRS channel estimator supports a set of three different DMRS symbol offset values for consecutive multi-slot lengths (i.e., 3 slots), which may includeNLD=MRS= 2, A^RI3 =28,32,37; N™RS= 3,= 10, 15,17.

[0077] FIG. 5C shows an example PDSCH DMRS channel estimator capability for the set of symbol offset values between symbols for scheduling length of 2 slots withNLD=MRS= 2 and A^RS2= 1,8,14,18,23. It is worth noting that it is straightforward to extend this example also to multi-slot scheduling lengths >2. For example, as shown in FIG. 5C, the set of symbol offset values may include a first symbol offset value 531, a second symbol offset value 532, a third symbol offset value 533, a fourth symbol offset value 534 and a fifth symbol offset value 535. Thus, if the first DMRS symbol is the DMRS symbol 512-1, the second DMRS symbol may be at one of the possible positions including positions 541, 542, 543, 544 and 545.

[0078] In some other embodiments, the set of supported symbol offset values may be a set of irregular symbol offset values for certain number of DMRS symbols. Here, irregular symbol offset values means that all consecutive DMRS symbols do not share the same symbol offset value. For example, if the plurality of consecutive slots includes 2 slots, the terminal device 110 may indicate that PDSCH DMRS channel estimator supports a set of three different DMRS symbol offset values for consecutive multi-slot lengths being 2, which may include A / ^RS= 2, ^DMRS'3^2 =24; / V™RS= 3,ADMRsIar L=3= 6, 10. Alternatively, or in addition, if the plurality of consecutive slots includes 3 slots, the terminal device 110 may indicate that PDSCH DMRS channel estimator supports a set of three different DMRS symbol offset values for consecutive multi-slot lengths being 3, which may include j / DMRS > nAirregular, L=3 >1 R.7DMRS > o A irregular, L=3.1 Q / VL=2 - > ^DMRS "l b> / VL=2 ~ ^DMRS - I4, I.

[0079] In some example embodiments, the capability information includes a set of supported symbol offset values and a number of DMRS symbols for a carrier frequency specific velocity. Alternatively, the capability information includes a set of supported symbol offset values and a number of DMRS symbols for Doppler information. In this case, the Doppler information may include at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, channel time variation in quantized form, or a time domain correlation value.

[0080] In some example embodiments, the capability information may include a set of supported symbol offset values that is based on at least one of: a start position of a set of sub-slot specific reserved symbols, an end position of the set of sub-slot specific reserved symbols, or the number of sub-slot specific reserved symbols. For example, the terminal device 110 may report via capability signaling one of: a maximum symbol offset assuming regular symbol distribution, a set of symbol offsets, or a of irregular symbol offsets subject to effective PDSCH allocation time which depends on the sub-slot specific reserved symbols at start rR“startwhere 1=1... L, and end, rR_Endof subslots. For example, the number of sub-slot specific reserved symbols, i.e. start, rR“startand end, TR-Endmay be predefined / hard coded. Alternatively, the network device 120 may configure the number of sub-slot specific reserved symbols, i.e. start, rR_startand end 7’}<_Endto the terminal device 110, based on which capability report is provided.

[0081] The terminal device 110 obtains (4020) at least one DMRS configuration for multi-slot scheduling of the plurality of consecutive slots. In some example embodiments, the at least one DMRS configuration may be preconfigured at the terminal device 110 and / or the network device 120. Alternatively, the terminal device 110 may obtain the at least one DMRS configuration from the network device 120. For example, the network device 120 may transmit the at least one DMRS configuration to the terminal device 110. In this case, the network device 120 may determine the at least one DMRS configuration, for example, based on the capability information. In this way, it enables to configure DMRS configuration according to UE’s DMRS channel estimator capability resulting into higher PDSCH throughput in various deployment scenarios. Further, new DMRS configurations enables the usage of multi-slot PDSCH in the presence of different UE speeds.

[0082] Each of the at least one DMRS configuration comprising the number of DMRS symbolsassociated with a symbol offset value between consecutive DMRS symbols. In some embodiments, the DMRS configuration further include at least one of: a DMRS configuration identity, a DMRS symbol type comprising a single symbol or a double symbol, an index of a first DMRS symbol, or the symbol offset value between the consecutive DMRS symbols.

[0083] Table 4 shows an example of PDSCH DMRS configurations for a multi-slot scheduling length of 2, where the 1st, 2nd, and 14th symbols are not available for DMRS. The symbol index of the 1st DMRS symbol is Po = 2, and the configurations include different numbers of DMRS symbols with regular symbol offset values between consecutive DMRS symbols. It is worth noting that example table captures only sub-set of all possible symbol offsets. Furthermore, it is assumed that the total number of DMRS symbols with L=2 does not exceed 5.Table 4DMRS config Single The number of DMRS symbols associated with regular symbol offset ID symbol between consecutive symbolsor 1 2 3 4 5 6 7 8 9 10 doublesymbol0 double PO 13 - - - - - - - - 1 double PO 24 - - - - - - - - 2 single PO 13 - - - - - - - - 3 single PO 24 - - - - - - - - 4 single PO 6 6 - - - - - - - 5 single PO 12 12 - - - - - - - 6 single PO 7 7 7 - - - - - - 7 single PO 8 8 8 - - - - - - 8 single PO 5 5 5 5 - - - - -9 single PO 6 6 6 6 - - - - -

[0084] Table 5 provides an example of PDSCH DMRS configurations for a multi-s ot scheduling length of 4, where the 1st, 2nd, and 14th symbols are not available for DMRS. The configurations feature different numbers of DMRS symbols, each with regular symbol offset values between consecutive DMRS symbols. It is noted that this is just example of single symbol configuration but also double symbol configurations can be designed accordingly.Table 5DMRS Single The number of DMRS symbols associated with regular symbol offset config ID symbol between consecutive symbolsor 1 2 3 4 5 6 7 8 9 10doublesymbol0 single P0 53 - - - - - - - - 1 single P0 26 - - - - - - - - 2 single P0 26 26 - - - - - - - 3 single P0 14 14 - - - - - - - 4 single P0 17 17 17 - - - - - - 5 single P0 12 12 12 - - - - - - 6 single P0 13 13 13 13 - - - - - 7 single P0 10 10 10 10 - - - - - 8 single P0 10 10 10 10 10 - - - - 9 single P0 7 7 7 7 7 - - - - 10 single P0 8 8 8 8 8 8 - - - 10 single P0 5 5 5 5 5 5 - - - 11 single P0 7 7 7 7 7 7 7 - - 12 single P0 5 5 5 5 5 5 5 - - 13 single P0 6 6 6 6 6 6 6 6 - 14 single P0 4 4 4 4 4 4 4 4 - 15 single P0 5 5 5 5 5 5 5 5 -16 single P0 3 3 3 3 3 3 3 3 3

[0085] In some example embodiments, the at least one DMRS configuration may be based on the capability information of the terminal device. For example, the at least one DMRS configuration is based on a same symbol offset value between DMRS symbols applicable over the plurality of consecutive slots. By way of example, the at least one DMRS configuration is based on consecutive DMRS symbols sharing same symbol offset value between different DMRS symbols over L consecutive slots. Alternatively, or in addition, the at least one DMRS configuration is based on a set of symbol offset values between DMRS symbols applicable over the plurality of consecutive slots. For example, the at least one DMRS configuration is based on all consecutive DMRS symbols not sharing same symbol offset value between different DMRS symbols over L consecutive slots. In some other example embodiments, the at least one DMRS configuration is based on the number of DMRS symbols and a symbol offset value between DMRS symbols for a carrier frequency specific velocity. In some further example embodiments, the at least one DMRS configuration is based on the number of DMRS symbols and a symbol offset value between DMRS symbols for Doppler information. In this case, the Doppler information comprises at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, a channel time variation in quantized form, or a time domain correlation value. For example, the Doppler information may include information capturing channel variation in quantizedform, e.g. “low speed ”up to 60 Km / h or “moderate speed > 60 km / h up to 120 km / h” or “high speed” from >120 km / h up to 200 km / h or “ultra-high speed” >200 km / h.

[0086] The network device 120 determines (4025) a target DMRS configuration. The network device 120 transmits (4030) an indication indicating the target DMRS configuration to the terminal device 110. That is, the terminal device 110 receives (4030) the indication indicating the target DMRS configuration from the network device 120. In some example embodiments, the indication may be transmitted via RRC signaling. Alternatively, the indication may be transmitted via medium access control (MAC) signaling, such as, MAC control element (MAC CE). In some other example embodiments, the indication may be transmitted via physical layer signaling, such as, downlink control information (DCI). For example, the indication may indicate the DMRS ID 1 in Table 4, which means that the target DMRS configuration is the DMRS in Table 4 with the DMRS I D=1. In this case, according to Table 4 above, the terminal device 110 is configured with DMRS ID=1 (2 double DMRS symbols = for higher rank, e.g. >4).

[0087] The terminal device 110 determines (4040) one or more DMRS symbol positions within the plurality of consecutive slots based on the target DMRS configuration. For example, upon reception of the multi-slot PDSCH scheduling information for a specific multi-slot scheduling length (i.e., the received (4030) indication), either via a configured grant or a dynamic grant, the terminal device 110 may determine the one or more DMRS symbol positions based on the multi-slot PDSCH scheduling information. This multi-slot PDSCH scheduling information may include a multi-slot DMRS configuration with regular symbol offset values between consecutive DMRS symbols, for a specific number of DMRS symbols. The scheduling information, whether from a configured or dynamic grant, may include a multi-slot DMRS configuration ID associated with the regular symbol offset and the number of DMRS symbols. In some example embodiments, the terminal device 110 determines DMRS symbol positions with regular symbol offsets within PDSCH resource over multi-slot scheduling length.

[0088] For example, if the indication may indicate the DMRS ID 1 in Table 4, the terminal device 110 may determine the second DMRS symbol position to be at index 3= P0+1 and third DMRS symbol position to be at index 26= PO+24 and fourth DMRS symbol position to be at index 27 = P0+ 24+1. As a result of this, now 1st and 3rd DMRS symbols (e.g. ranks 1-4) have regular symbol offset 24 and 2nd and 4th DMRS symbol (e.g. ranks 5-8) have also regular symbol offset 24.

[0089] Another example related to Table 4, if the indication may indicate the DMRS ID 9 (DMRS config I D=9) in Table 4, the terminal device 110 determines the second DMRS symbol position to be at index 8= PO+6 and third DMRS symbol position to be at index 14= 8 (2nd DMRS position) +6 and the fourth DMRS symbol position to be at index 20 = 14 (3rd DMRS position)* 6 and the fifth DMRS symbols position to be at index 26 = 20 (4th DMRS symbol position) + 6.

[0090] The terminal device 110 determines (4050) a channel estimation filter configuration based on a symbol offset between consecutive DMRS symbols. In some embodiments, the channel estimation filter configuration may include one-dimension DMRS channel estimation filter in time domain. Alternatively, the channel estimation filter configuration may include two-dimension DMRS channel estimation filter in both time and frequency domains. For example, the terminal device 110 computes, based on regular DMRS symbol offsets between consecutive DMRS symbols, DMRS channel estimation filter (e.g.1D or 2D- Wiener) across antenna port specific channel estimates over multiple DMRS symbols and / or resources in frequency domain.

[0091] In some example embodiments, the terminal device 110 may determine, for each antenna port, an antenna port specific channel estimation for each DMRS symbol. For example, the terminal device 110 computes antenna port specific multi-slot DMRS channel estimates for configured / indicated antenna ports for each DMRS symbol.

[0092] The terminal device 110 obtains (4060) an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration. For example, the terminal device 110 may obtain the actual channel estimate by applying the channel estimation filter configuration to the antenna port specific channel estimation. The terminal device 110 may perform 1D or 2D filtering (e.g. Wiener) over antenna port specific channel estimates to obtain actual channel estimate to be applied for the demodulation of multi-slot scheduled PDSCH. In this way, it enhances quality of antenna port specific channel estimates of PDSCH DMRS associated with regular symbol offsets with multiple DMRS symbols.

[0093] The network device 120 may transmit (4070) a multi-slot scheduled downlink transmission to the terminal device 110. For example, the network device 120 may transmit the multi-slot PDSCH with DMRS symbols. After receiving the multi-slot scheduled downlink transmission, the terminal device 110 may demodulate (4080) the multi-slot scheduled downlink transmission based on the actual channel estimate.

[0094] Reference is made to FIG. 6A, which illustrates a signaling flow of multi-slot DMRS in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the signaling flow 600 will be discussed with reference to the UE 610 and the gNB 620. The UE 610 may be or may be implemented at the terminal device 110 and the gNB 620 may be or may be implemented at the network device 120.

[0095] The UE 610 may send (6010), to the gNB 620, capability signaling for multi-slot scheduling PDSCH DMRS with maximum regular symbol offsets. For example, the UE 610 may report its PDSCH DMRS channel estimator capability for the maximum regular symbol offset value between consecutive DMRS symbols for a specific number of DMRS symbols for each multi-slot scheduling length. By wayof example, the multi-slot scheduling length (i.e., L) may be 2, 3 or 4. It is noted that the multi-slot scheduling length may be any suitable value.

[0096] The gNB 620 may determine (6020) DMRS configurations with regular symbol offset values for transmission of multi-slot PDSCH with different multi-slot scheduling lengths. The gNB 620 may configure (6030) the UE 610 with one or more DMRS configurations (for example, via RRC) with regular symbol offset values associated with different PDSCH multi-slot scheduling lengths.

[0097] The gNB 620 may send (6040) multi-slot scheduling information for PDSCH to the UE 610, for example, via DCI. The multi-slot scheduling information may include information about DMRS configuration ID, a multi-slot scheduling length, the number of DMRS symbols with regular symbol offsets between consecutive DMRS symbols.

[0098] The UE 610 may determine (6050) DMRS symbol positions with regular symbol offsets within PDSCH resource over multi-slot scheduling length. The gNB 620 may send (6060) the multi-slot PDSCH with DMRS symbols having regular symbol offset values between consecutive symbols.

[0099] The UE 610 may determine (6070) antenna port specific channel estimates for each DMRS symbol. The UE 610 may determine, based on regular symbol offsets, channel estimation filter (e.g., 1D or 2D-Wiener) across antenna port specific channel estimates over multiple DMRS symbols and perform (e.g., 1D or 2D) filtering over antenna port specific channel estimates to obtain actual channel estimates for the demodulation of PDSCH. The UE 610 may demodulate (6080) the multi-slot PDSCH with actual antenna port specific DMRS channel estimates associated with regular symbol offsets.

[0100] Reference is made to FIG. 6B, which illustrates a signaling flow of multi-slot DMRS in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the signaling flow 600’ will be discussed with reference to the UE 610 and the gNB 620. The UE 610 may be or may be implemented at the terminal device 110 and the gNB 620 may be or may be implemented at the network device 120.

[0101] The UE 610 may send (6010’), to the gNB 620, capability signaling for multi-slot scheduling PDSCH DMRS with a set of regular symbol offsets. For example, the UE 610 may report its PDSCH DMRS channel estimator capability for the set of regular symbol offset values between consecutive DMRS symbols for a specific number of DMRS symbols for each multi-slot scheduling length. The set of regular symbol offset values may include 2, 4, 6, 8 and 10. By way of example, the multi-slot scheduling length (i.e., L) may be 2, 3 or 4. It is noted that the multi-slot scheduling length may be any suitable value.

[0102] The gNB 620 may determine (6020’) DMRS configurations with the set of regular symbol offset values for transmission of multi-slot PDSCH with different multi-slot scheduling lengths. The gNB 620 may configure (6030’) the UE 610 with one or more DMRS configurations (for example, via RRC) withthe set of regular symbol offset values associated with different PDSCH multi-slot scheduling lengths.

[0103] The gNB 620 may send (6040’) multi-slot scheduling information for PDSCH to the UE 610, for example, via DCI. The multi-slot scheduling information may include information about DMRS configuration ID, a multi-slot scheduling length, the number of DMRS symbols with regular symbol offsets between consecutive DMRS symbols.

[0104] The UE 610 may determine (6050’) DMRS symbol positions with regular symbol offsets within PDSCH resource over multi-slot scheduling length. The gNB 620 may send (6060’) the multi-slot PDSCH with DMRS symbols having regular symbol offset values between consecutive symbols.

[0105] The UE 610 may determine (6070’) antenna port specific channel estimates for each DMRS symbol. The UE 610 may determine, based on regular symbol offsets, channel estimation filter (e.g., 1D or 2D-Wiener) across antenna port specific channel estimates over multiple DMRS symbols and perform (e.g., 1 D or 2D) filtering over antenna port specific channel estimates to obtain actual channel estimates for the demodulation of PDSCH. The UE 610 may demodulate (6080’) the multi-slot PDSCH with actual antenna port specific DMRS channel estimates associated with regular symbol offsets.

[0106] FIG. 7 shows a flowchart of an example method 700 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For example, the first apparatus may be implemented at the terminal device 110 in FIG. 1.

[0107] At block 710, the first apparatus transmits, to a second apparatus, capability information for demodulation reference signal, DMRS, channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0108] In some example embodiments, the capability information comprises a maximum supported symbol offset value between the DMRS symbols for a first number of DMRS symbols within the plurality of slots, or wherein the capability information comprises a fixed supported symbol offset value between the DMRS symbols for the first number of DMRS symbols within the plurality of slots.

[0109] In some example embodiments, the capability information comprises a set of supported symbol offset values between the DMRS symbols for a second number of DMRS symbols within the plurality of slots.

[0110] In some example embodiments, the capability information comprises a set of supported symbol offset values and a number of DMRS symbols for a carrier frequency specific velocity, or the capability information comprises a set of supported symbol offset values and a number of DMRS symbols for Doppler information, wherein the Doppler information comprises at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, a channel time variation in quantized form, or a time domain correlation value.

[0111] In some example embodiments, the capability information comprises a set of supported symbol offset values that is based on at least one of: a start position of a set of sub-slot specific reserved symbols, an end position of the set of sub-slot specific reserved symbols, or the number of sub-slot specific reserved symbols.

[0112] In some example embodiments, the capability information further indicates one or more other supported symbol offset values between DMRS symbols for multi-slot scheduling of another plurality of slots.

[0113] In some example embodiments, the method 700 further comprises: obtaining at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols.

[0114] I n some example embodiments, at block 720, the method 700 further comprises: receiving, from the second apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

[0115] In some example embodiments, the indication is in one of: radio resource control signaling, medium access control signaling, or physical layer signaling.

[0116] In some example embodiments, the method 700 further comprises: determining a channel estimation filter configuration based on a symbol offset between consecutive DMRS symbols; and obtaining an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration.

[0117] In some example embodiments, the first apparatus is a terminal device, and the second apparatus is a network device.

[0118] FIG. 8 shows a flowchart of an example method 800 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For example, the second apparatus may be implemented at the network device 120 in FIG. 1.

[0119] At block 810, the second apparatus receives, from a first apparatus, capability information for demodulation reference signal, DMRS, channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0120] In some example embodiments, the capability information comprises a maximum supported symbol offset value between the DMRS symbols for a first number of DMRS symbols within the plurality of slots, or wherein the capability information comprises a fixed supported symbol offset value between the DMRS symbols for the first number of DMRS symbols within the plurality of slots.

[0121] In some example embodiments, the capability information comprises a set of supported symboloffset values between the DMRS symbols for a second number of DMRS symbols within the plurality of slots.

[0122] In some example embodiments, the capability information comprises a set of supported symbol offset values and a number of DMRS symbols for a carrier frequency specific velocity, or the capability information comprises a set of supported symbol offset values and a number of DMRS symbols for Doppler information, wherein the Doppler information comprises at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, a channel time variation in quantized form,or a time domain correlation value.

[0123] In some example embodiments, the capability information comprises a set of supported symbol offset values that is based on at least one of: a start position of a set of sub-slot specific reserved symbols, an end position of the set of sub-slot specific reserved symbols, or the number of sub-slot specific reserved symbols.

[0124] In some example embodiments, the capability information further indicates one or more other supported symbol offset values between DMRS symbols for multi-slot scheduling of another plurality of slots.

[0125] In some example embodiments, the method 800 further includes: transmitting, to the first apparatus, at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols.

[0126] In some example embodiments, at block 820, the method 800 further comprises: transmitting, to the first apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

[0127] In some example embodiments, the indication is in one of: radio resource control signaling, medium access control signaling, or physical layer signaling.

[0128] In some example embodiments, the first apparatus is a terminal device, and the second apparatus is a network device.

[0129] FIG. 9 shows a flowchart of an example method 900 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For example, the first apparatus may be implemented at the terminal device 110 in FIG. 1.

[0130] At block 910, the first apparatus obtains at least one demodulation reference signal, DMRS, configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols.

[0131] At block 920, the first apparatus receives, from a second apparatus, an indication indicating atarget DMRS configuration from the at least one DMRS configuration.

[0132] In some example embodiments, obtaining the at least one DMRS configuration includes: receiving, from the second apparatus, the at least one DMRS configuration.

[0133] In some example embodiments, the at least one DMRS configuration is preconfigured at the first apparatus.

[0134] In some example embodiments, each of the at least one DMRS configuration further comprises at least one of: a DMRS configuration identity, a DMRS symbol type comprising a single symbol or a double symbol, an index of a first DMRS symbol, and the symbol offset value between the consecutive DMRS symbols.

[0135] In some example embodiments, the at least one DMRS configuration is based on at least one of: a same symbol offset value between DMRS symbols applicable over the plurality of slots, a set of symbol offset values between DMRS symbols applicable over the plurality of slots, the number of DMRS symbols and a symbol offset value between DMRS symbols for a carrier frequency specific velocity, or the number of DMRS symbols and a symbol offset value between DMRS symbols for Doppler information, wherein the Doppler information comprises at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, a channel time variation in quantized form, or a time domain correlation value.

[0136] In some example embodiments, the method 900 further comprises: transmitting, to the second apparatus, capability information for DMRS channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0137] In some example embodiments, the method 900 further comprises: determining a channel estimation filter configuration based on a symbol offset between consecutive DMRS symbols; and obtaining an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration.

[0138] In some example embodiments, the indication is in one of: radio resource control signaling, medium access control signaling, or physical layer signaling.

[0139] In some example embodiments, the first apparatus is a terminal device, and the second apparatus is a network device.

[0140] FIG. 10 shows a flowchart of an example method 1000 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For example, the second apparatus may be implemented at the network device 120 in FIG. 1.

[0141] At block 1010, the second apparatus determines a target demodulation reference signal, DMRS, configuration from at least one DMRS configuration for multi-slot scheduling of a plurality of slots,each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols.

[0142] At block 1020, the second apparatus transmits, to a first apparatus, an indication indicating the target DMRS configuration.

[0143] In some example embodiments, the method 1000 further comprises: transmitting, to the first apparatus, the at least one DMRS configuration.

[0144] In some example embodiments, the at least one DMRS configuration is preconfigured at the second apparatus.

[0145] In some example embodiments, each of the at least one DMRS configuration further comprises at least one of: a DMRS configuration identity, a DMRS symbol type comprising a single symbol or a double symbol, an index of a first DMRS symbol, and the symbol offset value between the consecutive DMRS symbols.

[0146] In some example embodiments, the at least one DMRS configuration is based on at least one of: a same symbol offset value between DMRS symbols applicable over the plurality of slots, a set of symbol offset values between DMRS symbols applicable over the plurality of slots, the number of DMRS symbols and a symbol offset value between DMRS symbols for a carrier frequency specific velocity, or the number of DMRS symbols and a symbol offset value between DMRS symbols for Doppler information, wherein the Doppler information comprises at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, a channel time variation in quantized form, or a time domain correlation value.

[0147] In some example embodiments, the method 1000 further comprises: receiving, from the first apparatus, capability information for DMRS channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots; and determining the target DMRS configuration based on the capability information.

[0148] In some example embodiments, the indication is in one of: radio resource control signaling, medium access control signaling, or physical layer signaling.

[0149] In some example embodiments, the first apparatus is a terminal device, and the second apparatus is a network device.

[0150] FIG. 11 shows a flowchart of an example method 1100 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For example, the first apparatus may be implemented at the terminal device 110 in FIG. 1.

[0151] At block 1110, the first apparatus determines one or more demodulation reference signal, DMRS, symbol positions within a plurality of slots based on a DMRS configuration.

[0152] At block 1120, the first apparatus determines a channel estimation filter configuration based ona symbol offset between consecutive DMRS symbols.

[0153] At block 1130, the first apparatus obtains an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration.

[0154] In some example embodiments, the method 1100 further comprises: determining, for each antenna port, an antenna port specific channel estimation for each DMRS symbol; and obtaining the actual channel estimate by applying the channel estimation filter configuration to the antenna port specific channel estimation.

[0155] In some example embodiments, the channel estimation filter configuration comprises one-dimension DMRS channel estimation filter in time domain or two-dimension DMRS channel estimation filter in both time and frequency domains.

[0156] In some example embodiments, the method 1100 further comprises: receiving, from the second apparatus, the multi-slot scheduled downlink transmission; and demodulating the multi-slot scheduled downlink transmission based on the actual channel estimate.

[0157] In some example embodiments, the method 1100 further comprises: transmitting, to the second apparatus, capability information for DMRS channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0158] In some example embodiments, the method 1100 further comprises: obtaining at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols.

[0159] In some example embodiments, the method 1100 further comprises: receiving, from the second apparatus, an indication indicating the DMRS configuration from the at least one DMRS configuration.

[0160] In some example embodiments, the indication is in one of: radio resource control signaling, medium access control signaling, or physical layer signaling.

[0161] In some example embodiments, the first apparatus is a terminal device, and the second apparatus is a network device.

[0162] In some example embodiments, a first apparatus capable of performing any of the method 700 (for example, the terminal device 110 in FIG. 1) may comprise means for performing the respective operations of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0163] In some example embodiments, the first apparatus comprises means for transmitting, to asecond apparatus, capability information for demodulation reference signal, DMRS, channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0164] In some example embodiments, the capability information comprises a maximum supported symbol offset value between the DMRS symbols for a first number of DMRS symbols within the plurality of slots, or wherein the capability information comprises a fixed supported symbol offset value between the DMRS symbols for the first number of DMRS symbols within the plurality of slots.

[0165] In some example embodiments, the capability information comprises a set of supported symbol offset values between the DMRS symbols for a second number of DMRS symbols within the plurality of slots.

[0166] In some example embodiments, the capability information comprises a set of supported symbol offset values and a number of DMRS symbols for a carrier frequency specific velocity, or the capability information comprises a set of supported symbol offset values and a number of DMRS symbols for Doppler information, wherein the Doppler information comprises at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, a channel time variation in quantized form, or a time domain correlation value.

[0167] In some example embodiments, the capability information comprises a set of supported symbol offset values that is based on at least one of: a start position of a set of sub-slot specific reserved symbols, an end position of the set of sub-slot specific reserved symbols, or the number of sub-slot specific reserved symbols.

[0168] In some example embodiments, the capability information further indicates one or more other supported symbol offset values between DMRS symbols for multi-slot scheduling of another plurality of slots.

[0169] In some example embodiments, the first apparatus further comprises: means for obtaining at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols.

[0170] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

[0171] In some example embodiments, the indication is in one of: radio resource control signaling, medium access control signaling, or physical layer signaling.

[0172] In some example embodiments, the first apparatus further comprises: means for determining a channel estimation filter configuration based on a symbol offset between consecutive DMRS symbols;and means for obtaining an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration.

[0173] In some example embodiments, the first apparatus is a terminal device, and the second apparatus is a network device.

[0174] In some example embodiments, a second apparatus capable of performing any of the method 800 (for example, the network device 120 in FIG. 1) may comprise means for performing the respective operations 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. The second apparatus may be implemented as or included in the network device 120 in FIG. 1.

[0175] In some example embodiments, the second apparatus comprises means for receiving, from a first apparatus, capability information for demodulation reference signal, DMRS, channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

[0176] In some example embodiments, the capability information comprises a maximum supported symbol offset value between the DMRS symbols for a first number of DMRS symbols within the plurality of slots, or wherein the capability information comprises a fixed supported symbol offset value between the DMRS symbols for the first number of DMRS symbols within the plurality of slots.

[0177] In some example embodiments, the capability information comprises a set of supported symbol offset values between the DMRS symbols for a second number of DMRS symbols within the plurality of slots.

[0178] In some example embodiments, the capability information comprises a set of supported symbol offset values and a number of DMRS symbols for a carrier frequency specific velocity, or the capability information comprises a set of supported symbol offset values and a number of DMRS symbols for Doppler information, wherein the Doppler information comprises at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, a channel time variation in quantized form, or a time domain correlation value.

[0179] In some example embodiments, the capability information comprises a set of supported symbol offset values that is based on at least one of: a start position of a set of sub-slot specific reserved symbols, an end position of the set of sub-slot specific reserved symbols, or the number of sub-slot specific reserved symbols.

[0180] In some example embodiments, the capability information further indicates one or more other supported symbol offset values between DMRS symbols for multi-slot scheduling of another plurality of slots.

[0181] In some example embodiments, the second apparatus comprises means for transmitting, to thefirst apparatus, at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols.

[0182] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

[0183] In some example embodiments, the indication is in one of: radio resource control signaling, medium access control signaling, or physical layer signaling.

[0184] In some example embodiments, the first apparatus is a terminal device, and the second apparatus is a network device.

[0185] In some example embodiments, a first apparatus capable of performing any of the method 900 (for example, the terminal device 110 in FIG. 1) may comprise means for performing the respective operations of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0186] In some example embodiments, the first apparatus comprises means for obtaining at least one demodulation reference signal, DMRS, configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; and means for receiving, from a second apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

[0187] In some example embodiments, the means for obtaining the at least one DMRS configuration comprises means for receiving, from the second apparatus, the at least one DMRS configuration.

[0188] In some example embodiments, the at least one DMRS configuration is preconfigured at the first apparatus.

[0189] In some example embodiments, each of the at least one DMRS configuration further comprises at least one of: a DMRS configuration identity, a DMRS symbol type comprising a single symbol or a double symbol, an index of a first DMRS symbol, and the symbol offset value between the consecutive DMRS symbols.

[0190] In some example embodiments, the at least one DMRS configuration is based on at least one of: a same symbol offset value between DMRS symbols applicable over the plurality of slots, a set of symbol offset values between DMRS symbols applicable over the plurality of slots, the number of DMRS symbols and a symbol offset value between DMRS symbols for a carrier frequency specific velocity, or the number of DMRS symbols and a symbol offset value between DMRS symbols forDoppler information, wherein the Doppler information comprises at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, a channel time variation in quantized form, or a time domain correlation value.

[0191] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, capability information for DMRS channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multislot scheduling of a plurality of slots.

[0192] In some example embodiments, the first apparatus further comprises: means for determining a channel estimation filter configuration based on a symbol offset between consecutive DMRS symbols; and means for obtaining an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration.

[0193] In some example embodiments, the indication is in one of: radio resource control signaling, medium access control signaling, or physical layer signaling.

[0194] In some example embodiments, the first apparatus is a terminal device, and the second apparatus is a network device.

[0195] In some example embodiments, a second apparatus capable of performing any of the method 1000 (for example, the network device 120 in FIG. 1) may comprise means for performing the respective operations of the method 1000. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the network device 120 in FIG. 1.

[0196] In some example embodiments, the second apparatus comprises means for determining a target demodulation reference signal, DMRS, configuration from at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; and means for transmitting, to a first apparatus, an indication indicating the target DMRS configuration.

[0197] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, the at least one DMRS configuration.

[0198] In some example embodiments, the at least one DMRS configuration is preconfigured at the second apparatus.

[0199] In some example embodiments, each of the at least one DMRS configuration further comprises at least one of: a DMRS configuration identity, a DMRS symbol type comprising a single symbol or a double symbol, an index of a first DMRS symbol, and the symbol offset value between the consecutive DMRS symbols.

[0200] In some example embodiments, the at least one DMRS configuration is based on at least one of: a same symbol offset value between DMRS symbols applicable over the plurality of slots, a set of symbol offset values between DMRS symbols applicable over the plurality of slots, the number of DMRS symbols and a symbol offset value between DMRS symbols for a carrier frequency specific velocity, or the number of DMRS symbols and a symbol offset value between DMRS symbols for Doppler information, wherein the Doppler information comprises at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, a channel time variation in quantized form, or a time domain correlation value.

[0201] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, capability information for DMRS channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots; and means for determining the target DMRS configuration based on the capability information.

[0202] In some example embodiments, the indication is in one of: radio resource control signaling, medium access control signaling, or physical layer signaling.

[0203] In some example embodiments, the first apparatus is a terminal device, and the second apparatus is a network device.

[0204] In some example embodiments, a first apparatus capable of performing any of the method 1100 (for example, the terminal device 110 in FIG. 1) may comprise means for performing the respective operations of the method 1100. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0205] In some example embodiments, the first apparatus comprises means for determining one or more demodulation reference signal, DMRS, symbol positions within a plurality of slots based on a DMRS configuration; means for determining a channel estimation filter configuration based on a symbol offset between consecutive DMRS symbols; and means for obtaining an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration.

[0206] In some example embodiments, the first apparatus further comprises: means for determining, for each antenna port, an antenna port specific channel estimation for each DMRS symbol; and means for obtaining the actual channel estimate by applying the channel estimation filter configuration to the antenna port specific channel estimation.

[0207] In some example embodiments, the channel estimation filter configuration comprises one-dimension DMRS channel estimation filter in time domain or two-dimension DMRS channel estimationfilter in both time and frequency domains.

[0208] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, the multi-slot scheduled downlink transmission; and means for demodulating the multi-slot scheduled downlink transmission based on the actual channel estimate.

[0209] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, capability information for DMRS channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multislot scheduling of a plurality of slots.

[0210] In some example embodiments, the first apparatus further comprises: means for obtaining at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols.

[0211] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, an indication indicating the DMRS configuration from the at least one DMRS configuration.

[0212] In some example embodiments, the indication is in one of: radio resource control signaling, medium access control signaling, or physical layer signaling.

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

[0214] FIG. 12 is a simplified block diagram of a device 1200 that is suitable for implementing example embodiments of the present disclosure. The device 1200 may be provided to implement a communication device, for example, the terminal device 110 or the network device 120 as shown in FIG. 1. As shown, the device 1200 includes one or more processors 1210, one or more memories 1220 coupled to the processor 1210, and one or more communication modules 1240 coupled to the processor 1210.

[0215] The communication module 1240 is for bidirectional communications. The communication module 1240 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 1240 may include at least one antenna.

[0216] The processor 1210 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 1200 may have multiple processors, such as anapplication specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0217] The memory 1220 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) 1224, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random-access memory (RAM) 1222 and other volatile memories that will not last in the power-down duration.

[0218] A computer program 1230 includes computer executable instructions that are executed by the associated processor 1210. The instructions of the program 1230 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 1230 may be stored in the memory, e.g., the ROM 1224. The processor 1210 may perform any suitable actions and processing by loading the program 1230 into the RAM 1222.

[0219] The example embodiments of the present disclosure may be implemented by means of the program 1230 so that the device 1200 may perform any process of the disclosure as discussed with reference to FIG. 2 to FIG. 11. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0220] In some example embodiments, the program 1230 may be tangibly contained in a computer readable medium which may be included in the device 1200 (such as in the memory 1220) or other storage devices that are accessible by the device 1200. The device 1200 may load the program 1230 from the computer readable medium to the RAM 1222 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0221] FIG. 13 shows an example of the computer readable medium 1300 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1300 has the program 1230 stored thereon.

[0222] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, orusing 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.

[0223] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machineexecutable 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.

[0224] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general-purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0225] In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0226] 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 combinationof the foregoing.

[0227] Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable subcombination.

[0228] 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 first apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to:obtain at least one demodulation reference signal, DMRS, configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between DMRS symbols; andreceive, from a second apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

2. The first apparatus of claim 1, wherein the first apparatus is caused to obtain the at least one DMRS configuration by:receiving, from the second apparatus, the at least one DMRS configuration.

3. The first apparatus of claim 1, wherein the at least one DMRS configuration is preconfigured at the first apparatus.

4. The first apparatus of any of claims 1-3, wherein each of the at least one DMRS configuration further comprises at least one of:a DMRS configuration identity,a DMRS symbol type comprising a single symbol or a double symbol,an index of a first DMRS symbol, andthe symbol offset value between the DMRS symbols.

5. The first apparatus of any of claims 1 -4, wherein the at least one DMRS configuration is based on at least one of:a same symbol offset value between DMRS symbols applicable over the plurality of slots, a set of symbol offset values between DMRS symbols applicable over the plurality of slots, the number of DMRS symbols and a symbol offset value between DMRS symbols for a carrier frequency specific velocity, orthe number of DMRS symbols and a symbol offset value between DMRS symbols for Doppler information, wherein the Doppler information comprises at least one of the following: a Doppler frequencyoffset, a Doppler frequency spread value, a channel time variation in quantized form, or a time domain correlation value.

6. The first apparatus of any of claims 1-5, wherein the first apparatus is caused to:transmit, to the second apparatus, capability information for DMRS channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots.

7. The first apparatus of any of claims 1-6, wherein the first apparatus is caused to:determine a channel estimation filter configuration based on a symbol offset between DMRS symbols; andobtain an actual channel estimate to be applied to a demodulation of multi-slot scheduled downlink transmission by applying the channel estimation filter configuration.

8. The first apparatus of any of claims 1-7, wherein the indication is in one of:radio resource control signaling,medium access control signaling, orphysical layer signaling.

9. The first apparatus of any of claims 1-8, wherein the first apparatus is a terminal device, and the second apparatus is a network device.

10. A second apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to:determine a target demodulation reference signal, DMRS, configuration from at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between DMRS symbols; andtransmit, to a first apparatus, an indication indicating the target DMRS configuration.

11. The second apparatus of claim 10, wherein the second apparatus is caused to:transmit, to the first apparatus, the at least one DMRS configuration.

12. The second apparatus of claim 10, wherein the at least one DMRS configuration is preconfigured at the second apparatus.

13. The second apparatus of any of claims 10-12, wherein each of the at least one DMRS configuration further comprises at least one of:a DMRS configuration identity,a DMRS symbol type comprising a single symbol or a double symbol,an index of a first DMRS symbol, andthe symbol offset value between the DMRS symbols.

14. The second apparatus of any of claims 10-13, wherein the at least one DMRS configuration is based on at least one of:a same symbol offset value between DMRS symbols applicable over the plurality of slots, a set of symbol offset values between DMRS symbols applicable over the plurality of slots, the number of DMRS symbols and a symbol offset value between DMRS symbols for a carrier frequency specific velocity, orthe number of DMRS symbols and a symbol offset value between DMRS symbols for Doppler information, wherein the Doppler information comprises at least one of the following: a Doppler frequency offset, a Doppler frequency spread value, a channel time variation in quantized form, or a time domain correlation value.

15. The second apparatus of any of claims 10-14, wherein the second apparatus is caused to: receive, from the first apparatus, capability information for DMRS channel estimation, the capability information indicating one or more supported symbol offset values between DMRS symbols for multi-slot scheduling of a plurality of slots; anddetermine the target DMRS configuration based on the capability information.

16. The second apparatus of any of claims 10-15, wherein the indication is in one of:radio resource control signaling,medium access control signaling, orphysical layer signaling.

17. The second apparatus of any of claims 10-16, wherein the first apparatus is a terminal device, and the second apparatus is a network device.

18. A method comprising:obtaining, at a first apparatus, at least one demodulation reference signal, DMRS, configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; and receiving, from a second apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

19. A method comprising:determining, at a second apparatus, a target demodulation reference signal, DMRS, configuration from at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; andtransmitting, to a first apparatus, an indication indicating the target DMRS configuration.

20. A first apparatus comprising:means for obtaining at least one demodulation reference signal, DMRS, configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; and means for receiving, from a second apparatus, an indication indicating a target DMRS configuration from the at least one DMRS configuration.

21. A second apparatus comprising:means for determining a target demodulation reference signal, DMRS, configuration from at least one DMRS configuration for multi-slot scheduling of a plurality of slots, each of the at least one DMRS configuration comprising the number of DMRS symbols associated with a symbol offset value between consecutive DMRS symbols; andmeans for transmitting, to a first apparatus, an indication indicating the target DMRS configuration.

22. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 18 or 19.

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