GB2623069A

GB2623069A - Devices, methods and apparatuses for antenna port configuration

Info

Publication number: GB2623069A
Application number: GB2214405.9A
Authority: GB
Inventors: Yuk Youngsoo; Pekka Karjalainen Juha; Eino Tapio Kinnunen Pasi; Luoto Petri
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2022-09-30
Filing date: 2022-09-30
Publication date: 2024-04-10
Also published as: GB202214405D0; WO2024069274A1

Abstract

3GPP TS 38.212 sets out the requirements for DCI format 0_1, for scheduling (uplink) PUSCH. This includes a field which combines precoding information (i.e. transmitted precoding matrix indicator, TPMI) and number of layers (aka rank). DCI format 0_1 also includes an antenna ports field. The antenna ports field provides an index into rank specific tables, from which demodulation reference signal (DMRS) ports can be deduced. However, here, the invention lies in adopting new antenna port configuration information, which appears intended to replace DCI format 0_1. The antenna port configuration information includes first configuration information and second configuration information. The first configuration information indicates (preferably only) the number of layers. The second configuration information indicates TPMI or/and antenna port information (e.g. DMRS ports). Preferably, an appropriate antenna ports table (see tables 1-4) can be identified from the first configuration information and the second configuration information indexes into the identified antenna ports table. The antenna ports table preferably includes TPMI and DMRS ports; the second configuration information thus preferably provides a combined indication of antenna ports and TPMI. The invention allows the antenna port configuration to cope with more than 4 layers, without requiring an increase in configuration bits.

Description

DEVICES, METHODS AND APPARATUSES FOR ANTENNA PORT CONFIGURATION

FIELD

100011 Embodiments of the present disclosure generally relate to the field of communication, and in particular. to devices, methods, apparatuses and computer readable storage medium for antenna port configuration.

BACKGROUND

[0002] Enhancements on uplink (UL) and downlink (DL) operations have been approved to be considered and specified as part of the multiple input multiple output (MIMO) evolution in the third generation partnership project (3GPP) radio access network (RAN) #94. Target channels of the enhancements include at least the Physical Uplink Shared Channel (PUSCH) and Physical Uplink Control Channel (PUCCH). Enhanced solutions may involve UL demodulation reference signal (DMRS) and sounding reference signal (SRS) enhancements.

100031 The 3GPP Release 17 (Re1-17) specification provides the support of 4 DMRS ports for PUSCH. In 3GPP release 18 (Rel-18), it is agreed to support 8 DMRS ports. 20 However, to enable support for up to 8 DMRS ports, there is a need for improved solutions regarding antenna port configuration.

SUMMARY

[0004] In general, example embodiments of the present disclosure provide devices, 25 methods, apparatuses and computer readable storage medium for antenna port con figuration.

[0005] In a first aspect, there is provided a terminal device. The terminal device may comprise one or more transceivers; and one or more processors communicatively coupled to the one or more transceivers, and the one or more processors are configured to cause the terminal device to: receive, from a network device, antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers. and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPNII, or antenna port information; and determine an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.

[0006] In a second aspect, there is provided a network device. The network device may comprise one or more transceivers; and one or more processors communicatively coupled to the one or more transceivers, and the one or more processors are configured to cause the network device to: obtain antenna port configuration information comprising at. least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of: a transmitted preceding matrix indicator, TPNII, or antenna port information; and transmit, to a terminal device, the antenna port configuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to be used for an uplink reference signal.

[0007] In a third aspect, there is provided a method implemented at a terminal device.

The method may comprise: receiving, from a network device, antenna port configuration information comprising at least firs( configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPNIT or antenna port information; and determinin an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.

[0008] In a fourth aspect, there is provided a method implemented at a network device. The method may comprise: obtaining antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of: a transmitted precoding matrix indicator, TPNII, or antenna port information; and transmitting, to a terminal device, the antenna port configuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to be used for an uplink reference signal.

[0009] In a fifth aspect, there is provided an apparatus of a terminal device. The apparatus may comprise: means for receiving, from a network device, antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPMI, or antenna port information; and means for determining an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.

100101 In a sixth aspect, there is provided an apparatus of a network device. The apparatus may comprise: means for obtaining antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of: a transmitted preceding matrix indicator, TPMI, or antenna port information; and transmitting, to a terminal device, the antenna port configuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to be used for an uplink reference signal.

[0011] In a seventh aspect, there is provided a terminal device. The teiiuinal device may comprise at least one processor; and at least one memory including computer program codes, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to: receive, from a network device, antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPMI, or antenna port information; and determine an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.

100121 In an eighth aspect, there is provided a network device. The network device may comprise at least one processor; and at least one memory including computer program codes, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the network device to obtain antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPMI, or antenna port information; and transmit, to a terminal device, the antenna port configuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to be used for an uplink reference signal.

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

[0014] In a tenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least lo: receive, From a network device, antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPMI, or antenna port information; and determine an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.

[0015] In an eleventh aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: obtain antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of: a transmitted precoding matrix indicator. TPMI, or antenna port information; and transmit, to a terminal device, the antenna port configuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to be used for an uplink reference signal, [0016] In a twelfth aspect, there is provided a terminal device. The terminal device may comprise receiving circuitry configured to receive, from a network device, antenna port configuration information comprising at leas( first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPMI, or antenna port information; and determining circuitry configured to determine an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.

[0017] In a thirteenth aspect, there is provided a network device. The network device may comprise obtaining circuitry configured to obtain antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of: a transmitted precoding matrix indicator, TPMI, or antenna port information; and transmitting circuitry configured to transmit, to a terminal device, the antenna port configuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to be used for an uplink reference signal.

100181 It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Some example embodiments will now be described with reference to the accompanying drawings, where: [0020] FIG. 1 illustrates an example network environment in which example embodiments of the present disclosure may be implemented; [0021] FIG. 2 illustrates an example flowchart of a method implemented at a terminal 20 device according to example embodiments of the present disclosure; [0022] FIG. 3A and FIG. 3B illustrate example UL DMRS port mapping for DMRS type 1 and DMRS type 2 respectively, [0023] FIG. 4 illustrates example SRS antenna port group to DMRS code division multiplexing (CDM) group mapping for DMRS type 1; 100241 FIG. 5 illustrates an example flowchart of a method implemented at a network device according to example embodiments of the present disclosure; [0025] FIG. 6 illustrates an example simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure; and [0026] FIG. 7 illustrates an example block diagram of an example computer readable 30 medium in accordance with some embodiments of the present disclosure.

100271 Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

100281 Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

100291 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.

[0030] References in the present disclosure to "one embodiment," "an embodiment," "an example embodiment," and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within die knowledge of one skilled in the art to affect such feature, structure or characteristic in connection with other embodiments whether or not explicitly described.

100311 It shall be understood that although the terms "first" and "second" etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could he termed a second element, and similarly, a second element could he 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.

[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", "has", "having", "includes" and/or "including", when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/ or combinations thereof. As used herein, "at least one of the following: <a list of two or more elements>" and "at least one of <a list of two or more elements>" and similar wording, where the list of two or more elements are joined by "and" or "or", mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

100331 As used in this application, the term circuitry may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0034] 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.

100351 As used herein, the term "communication network" refers to a network following 30 any suitable communication standards, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-loT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may he performed according to any suitable generation communication protocols, including, but not limited to, the third generation (30), the fourth generation (40), 4.50, the future fifth generation (50) communication protocols, and/or any other protocols either currently known or to he developed in the future. Embodiments of the present disclosure may he 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 he embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

100361 As used herein, the term network device" refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a New Radio (NR) NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.

100371 The term "terminal device" refers to any end device that may he 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 telminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VolP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME). USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

100381 In Technical Specification (TS) 38.212, for DL physical downlink shared channel (PDSCH), 8 antenna port DMRS is supported with port mapping. In DL, the transmission rank is dynamically signaled with downlink control information (DCI) (for example, format 1 1) via a table where a large number of entries associated with different antenna port combinations are required. However, for UL PUSCH, the transmission rank is indicated separately by "Precoding information and layers" (codebook based PUSCH), or SRS resource indicator (non-codebook based PUSCH) codepoint fields. Upon the reception of the aforementioned information, the UE may use the corresponding rank-specific DMRS port indication table with the signaled antenna port value.

[0039] In Re1-17. DCI signaling for PUSCH antenna port mapping is related to the following two fields: - Antenna port(s), and - Precoding information and number of layers.

[0040] When transform precoding is disabled (cyclic prefix orthogonal frequency division multiplexing (OFDM), CP-OFDM) and double symbol DMRS is configured, the number of bits for the "Antenna port(s)" field is 4 or 5 bits according to the DMRS type =1 or 2, 20 respectively.

[0041] When the UE is configured with codebook-based PUSCH, the number of bits for the "Precoding information and number of layers" field is up to 6 according to the number of UL transmission (TX) antenna ports, max rank, codebook subset and FullPowerTransmission mode configured. For example, when the antenna port number is 4 and the maxRank is 2 or 3 or 4, for the UE supporting full coherent, the number of bits for the "Precoding information and number of layers" field is 6. For UE supporting partial coherent, the number of bits for the "Precoding information and number of layers" field is 5. For UE supporting non-coherent, the number of bits for the "Precoding information and number of layers" field is 4.

[0042] In 3GPP RAN#94, enhancements on UL and DL DMRS operation are approved to be considered and specified as part of the MIMO evolution for DL and UP WID in RP-213598. The objectives for 8 transmission (TX) UL operations including DMRS enhancements are stated as follows: The work item aims to specify the enhancements identified for NR MIMO. The detailed RANI objectives are as follows: 5. Study, and if justified, specify UL DMRS, SRS, SRI, and TPM1 (including codebook) enhancements to enable 8 Tx UL operation to support 4 and more layers per UE in UL targeting CPE/FWA/vehicle/Industrial devices Note: Potential restrictions on the scope of this objective (including coherence assumption, full/non-full power modes) will be identified as part of the study.

[0043] If the legacy signaling methodology is followed, a larger number of bits needs to be signaled. Therefore, it would be beneficial to define a signaling scheme where signaling overhead can be reduced even if the number of antenna ports and different rank values is increased. Thus, to enable support for up to 8 antenna ports in Re1-18 for PUSCH, antenna port mapping and related indication mechanisms for UL DMRS should be improved.

100441 On the other hand, there has been no any study on the potential impact of UL DMRS design and related signaling aspects. To enable support for different UE implementation options for 8 TX, it is highly important that signaling related to 8 TX antenna port indication may provide flexible support for different implementation options.

[0045] Tn view of the above, for enhancements on UL and DL DMRS operation, 8TX UL 15 operations including DMRS enhancements shall be supported. Therefore, there is a need for improved solutions for antenna port configuration, especially, a principle of DMRS port mapping and signaling of DM-RS port indication for 8TX PUSCH support.

[0046] According to embodiments of the present disclosure, there is providing a scheme for antenna port configuration. With this scheme, a terminal device receives, from a network device, antenna port configuration information. The antenna port configuration information comprises at least first configuration information and second configuration information. The first configuration information indicates a number of transmission layers, and the second configuration information indicates at least one of a transmitted precoding matrix indicator (TPMI) or antenna port information. Moreover, the terminal device determines an antenna port configuration to be used for an uplink reference signal and/or data transmission based on the antenna port configuration information.

[0047] By using of this antenna port configuration, this scheme may optimize antenna port configuration for supporting various DMRS port mapping. for example. for 8TX PUSCH. In this way, it is possible to save signaling overhead by using fewer hits to indicate the antenna-related information and thus improve transmission efficiency.

[0048] The term "SRS ports" or "UL TX ports" refer to real TX antenna port, which may be indexed as, for example, 1000+x, such as 1000, 1001, 1002,... The term "DMRS ports" refers to logical ports indicating DMRS resource elements (REs) and sequences, which may be indexed as, for example, y = 0, 1, The term "TPMI" refers to transmitted precoding matrix indicator, which is used for generating layers from a linear combination of SRS 10 ports.

[0049] The term "CDM group" refers to a group of DMRS ports multiplexed by different OCC (Orthogonal Cover Code) within a same DMRS resource element. Antenna port mapping is for one-to-one mapping of layers to DMRS ports. For example, for UE having 4 transmission layers and up to 8 DMRS ports, example antenna mappings could be as follows: UE1: layer 1,2,3,4 4 DMRS ports 0,1,4,5 (CDM group 0) UE2: layer 1,2,3,4 4 DMRS ports 2,3,6,7 (CDM group 1) [0050] Hereinafter, principle and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Reference is first made to 20 FIG. 1, which illustrates an example environment 100 in which example embodiments of the present disclosure can be implemented.

[0051] The environment 100, which may be a part of a communication network, comprises a terminal device 110 and a network device 120 communicating with each other or with other devices via each other.

[0052] The communication environment 100 may comprise any suitable number of devices and cells. In the communication environment 100, the terminal device 110 and the network device 120 can communicate data and control information with each other. A link from the network device 120 to the terminal device 110 is referred to as a downlink (DL), while a link from the terminal device 110 to the network device 120 is referred to as an uplink (UL).

[0053] It is to be understood that two devices are shown in the environment 100 only for the purpose of illustration, without suggesting any limitation to the scope of the present disclosure. In some example embodiments, the environment 100 may comprise a further device to communicate with the terminal device 110 and network device 120.

100541 The communications in the environment 100 may follow any suitable communication standards or protocols, which are already in existence or to be developed in the future, such as Universal Mobile Telecommunications System (UMTS), long term evolution (LTE), LTE-Advanced (LTE-A), the fifth generation (5G) New Radio (NR), Wireless Fidelity (Wi-Fi) and Worldwide Interoperability for Microwave Access (WiMAX) standards, and employs any suitable communication technologies, including, for example, Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), time division multiplexing (TDM), frequency division multiplexing (FDM), code division multiplexing (CDM), Bluetooth, ZigBee, and machine type communication (MTC), enhanced mobile broadband (eMBB), massive machine type communication (mMTC), ultra-reliable low latency communication (URLLC), Carrier Aggregation (CA), Dual Connectivity (DC), and New Radio Unlicensed (NR-U) technologies.

100551 FIG. 2 illustrates an example flowchart of a method 200 implemented at a terminal device according to example embodiments of the present disclosure. For the purpose of discussion, the method 200 will be described from the perspective of the terminal device 110 with reference to FIG. 1.

[0056] As shown in FIG. 2, at block 210, the terminal device 110 may receive, from the network device 120, antenna port configuration information. The antenna port configuration information may comprise at least first configuration information and second configuration information. The first configuration information may indicate a number of transmission layers, and the second configuration information may indicate at least one of a TPMI or antenna port information.

[0057] In some example embodiments, the first configuration information may correspond to a new field called, for example, -the number of layers". The second configuration information may correspond to another field called, for example, -precoding (TPMI) and antenna port(s)" indicating a "precoding (TPMI) and antenna port(s)" table. For example, different tables may be used for different numbers of layers, or in other words, different ranks.

100581 It can be seen that the antenna port configuration approach proposed herein is different from the existing antenna port configuration approach in Rd-17, In the existing antenna port configuration approach. the antenna port configuration information comprises a "TPMI and the number of layers" field and an "antenna port" field. In other words, a field is used to indicate the TPMI and the number of layers, and another field is used to indicate the antenna port. While, in some example embodiments according to the present disclosure, the antenna port configuration information may comprise the "the number of layers" field and the "preceding (TPMI) and antenna port(s)" field. The "the number of layers" field may be used to determine a mapping table for determining the precoding (TPMI) and antenna port(s) information using the "precoding (TPMI) and antenna port(s)" field. For example, the -the number of layers" field and the "precoding and antenna port(s)" field may be carried in the same signaling message.

[0059] In some example embodiments, the antenna port configuration information may be indicated by at least 4 bits. The first configuration information may be indicated by at least 2 bits. The second configuration information may be indicated by at least 1 bit.

[0060] As an example, the total number of bits for precoding, layers and antenna ports may be the same for both Rel-17 and Rd-18. For example, the antenna port configuration information proposed herein may be indicated by 10 bits. According to the existing antenna port configuration approach, the antenna port configuration information comprises 6 bits for the"Precoding and layer" field and 4 bits for the "Antenna port" field. While in some example embodiments according to the disclosure, the antenna port configuration information may comprise 3 bits for the "the number of layers" field and 7 bits for the "Precoding (TPMI) and antenna port(s)" field. In this case, the first configuration information may be indicated by 3 bits and the second configuration information may be indicated by 7 bits. Alternatively or additionally, the total number of bits for precoding, layers and antenna ports may be lower than the existing antenna port configuration approach in Rd-17 by dividing tables per layer. In this case, for example, the "Precoding (TPMI) and antenna port(s)" field may comprise 4-6 bits. In addition, the antenna port mapping may depend on TPMI, and combination of the TPMI and antenna port mapping may be efficient from the perspective of signaling.

[0061] Then, as shown in FIG. 2, at block 220, the terminal device 110 may determine an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information. In some example embodiments, the terminal device 110 may determine an antenna port configuration to be used for an uplink reference signal and data transmission based on the first and second configuration information. For example, the uplink reference signal may comprise a DMRS.

[0062] In some example embodiments, the terminal device 110 may determine at least one mapping table associated with the second configuration information based on the first configuration information. In this case, the at least one of the TPM I and the antenna port information may be determined based on the at least one mapping table and the second configuration information.

[0063] In some embodiments, the at least one mapping table may comprise a first mapping for uplink reference signal power boosting and a second mapping for increasing uplink throughput. In some example embodiments, the terminal device 110 may obtain an ordering of selection of uplink reference signal transmission ports corresponding to the number of transmission layers indicated by the first configuration information based on the at least one mapping table.

100641 In addition, the inventors further notice that in current Rel-17. DMRS port mapping and indication mechanisms do not take into account potential antenna port phase coherency assumptions between different antenna ports/groups of antenna ports (for example, non-coherency, partial coherency. full-coherency). However, the inventors further notice that in Rd-18, 8TX coherent PUSCH antenna port configuration is expected to be more complex than the legacy configuration (that is, 4 antenna ports). Thus the inventors propose taking into account the concept of a coherent group in designing a signaling table. In other words, different coherency assumptions between different antenna ports/groups of antenna ports should be considered in the 8 TX UL precoder design.

[0065] Therefore, in the present disclosure, it is further proposed that the terminal device 25 may report its antenna port coherency capability and the the network device may configure at least one corresponding codebook subset. In other words, the mapping table may be associated with codebook subset configuration.

[0066] In some example embodiments, the terminal device 110 may transmit, to the network device 120, the antenna port coherency capability of the terminal device 110.

The network device 120 may configure the terminal device with corresponding codebook subset corresponding to the antenna port coherency capability. Then, the terminal device 110 may receive, from the network device 120, a codebook subset configuration. For example, the codebook subset configuration may correspond to the coherency capability. In this case, for example, the terminal device 110 may determine at least one of the TPMI or the antenna port information based on the first configuration information, the second configuration information and the codebook subset configuration.

[0067] In some embodiments, the antenna port coherency capability may comprise one of a group comprising one or more of: full-coherent capability, partial-coherent capability, or non-coherent capability. The netword device may configure the codebook subset respectively corresponding to any of full-coherent capability, partial-coherent capability, or non-coherent capability.

100681 The term -coherent" used herein may refer to property of antenna ports. If the maximum difference of measured relative power errors between different antenna ports is less than a predetermined threshold and/or the maximum difference of relative phase errors between the different antenna ports (in any slot within a specified time window) is less than a threshold, these antenna ports may be regarded as coherent. For example, if the maximum difference of relative phase errors between different antenna ports is less than 40 degrees and/or the maximum difference of relative power errors between different antenna ports is less than 4dB within a 20ms time window, these antenna polls are coherent.

[0069] The term "full-coherent capability" may refer to, for a terminal device, all antenna ports of the terminal device being coherent with each other. The term "partial-coherent capability" may refer to, for a terminal device, antenna ports of a group being coherent and antenna ports of different groups being not coherent. The term "non-coherent capability" may refer to, for a temmial device, any two antenna ports being not coherent.

100701 In some embodiments, it may design mapping tables respectively corresponding to different codebook subsets which correspond to different antenna port coherency capability.

100711 Hereinafter, for illustrative purposes, some example mapping tables respectively corresponding to different codebook subsets will be described to enable the skilled in the art to understanding the solution as proposed herein. It is to be noted that these tables are only provided for illustrative purposes without suggesting any limitations in any way.

A. Full-coherent Capability and Codebook Subset=fullyAndPartialAndNonCoherent 100721 In this example case, it is assumed that the terminal device 110 supporting full-coherent capability and the terminal device is configured with codebook subset corresponding lo fullyAndPartialAndNonCoherent.

100731 In some example embodiments, the terminal device 110 may receive, from the network device 120, a first codebook subset configuration for fully, partial and non-coherent, corresponding to the full-coherent capability. In this case, the at least one mapping table may comprise at least one first mapping table corresponding to the first codebook subset configuration. In this case, for example, the terminal device 110 may report full-coherent capability and network device 120 may configure the codebookSubset as fullyAndPartialAndNonCoherent.

[0074] In such a case, the at least one first mapping table may comprise one or more 10 mapping tables corresponding to different numbers of transmission layers, and each may comprise indexes of the second configuration information, and TPMIs and DMRS ports respectively corresponding to the indexes [0075] In some example embodiments, the first mapping table may comprise TPMI information, and the layers to DMRS port mapping may be fixed if single user MIMO transmission is used, according to the number of transmission layers.

[0076] Design of the DMRS port mapping may consider one or more of the following aspects: Power balancing for different CDM groups as we used in DL mapping Coherent ports to the same DMRS CDM group Options for DMRS power boosting vs. UL peak through( for layers up to 4.

[0077] Regarding the power balancing between CDM groups, it is intended for efficient power mapping to different CDM groups. It is recommended to support the balanced port mapine betwen two CDM groups. For example, for DMRS type 1, CDM group 0 may be mapped to DMRS ports 0,1,4.5, and CDM group I may be mapped to DMRS ports 2,3,6,7.

100781 Also, mixing non-coherent ports in the same CDM group may not be efficient. In NR multi transmission reception point (multi-TRP) operation, because this is based on Non-Coherent Joint Transmission (NC-JT), there may be a restriction that only coherent port (from the same TRP) may be multiplexed into the same CDM group. So, this principle may be good to be supported in 8 TX UL transmission.

100791 For the terminal device supporting full-coherent capability, there may be no restriction for mapping layers associated with an SRS antenna port group to DMRS CDM group. Any layer may be mapped to any DMRS port. In this case, power balancing may be considered for determining UL DMRS ports to be mapped with resources. Only single DMRS port mapping may he supported for a number of layers.

100801 FIG. 3A and FIG. 3B illustrate example UL DMRS port mapping for DMRS type 1 and DMRS type 2 respectively. As shown in FIG. 3A in UL DMRS port mapping for DMRS type 1, two CDM groups, i.e., DMRS CDM group 0 and DMRS CDM group 1 may be used and they may be respectively mapped to DMRS ports 0, 1, 4 and 5 and DMRS ports 2, 3, 6, and 7.

100811 As shown in FIG. 3B, in UL DMRS port mapping for DMRS type I. three CDM 10 groups, i.e., DMRS CDM group 0, DMRS CDM group 1, and DMRS CDM group 2 may be used and three CDM groups may be mapped to DMRS ports 0, 1, 6 and 7. DMRS port 2, 3, 8 and 9 and DMRS port 4, 5, 10 and 11 respectively.

[0082] In some embodimetns, for example, for 5 to 8 layers, the DMRS port mapping order may be for example, DMRS port {0,1,2,3,4,6,5,7} for DMRS type 1 and/or DMRS port {0,1,2,3,6,8,7,9} for DMRS type 2. For DMRS type 1, DMRS ports 5 and 6 are swapped in the mapping order, and the reason lies in that it may provide power balance between different CDM groups, for example, when rank 6 is used. For DMRS type 2, only two CDM groups may be used and, due to the same reason as DMRS type 1, DMRS ports 7 and 8 are swapped in the mapping order.

100831 As a further example, for 1-4 layers, the DMRS port mapping order may be either {0,1,23} or {0,1,4,5} for DMRS type 1, and either {0,1,2,3} or {0,1,6,7} for DMRS type 2. The first mapping may be for coverage with DMRS power boosting, while the second mapping may be for the throughput without DMRS power boosting and with PUSCH multiplexing in DMRS symbols.

100841 As an example, Tables 1-4 show example first mapping tables corresponding to different ranks, 5 to 8.

Table 1: TPMI and Antenna port(s), transform preeoder is disabled codebookSubset = fullvAndPartialAndNonCoherent, dmrs-Type=1, maxtength =2, rank=5 0-4 X1 X2 0-4 0-4 X3 ****** * ,-;*** *-*-* ******** * uLNumber f4DIVIRS:C i*gteptip(s) without data 3 2 X4 0-4 2 2 0-4 2 M 2 XM 0-4 2 Table 2: TPMI and Antenna port(s), transform precoder is disabled codebookSubset = fullyAndPartialAndNonCoherent, dmrs-Type=1, maxLength =2, rank=6 Table 3: TPMI and Antenna port(s), transform precoder is disabled, codebookSubset = fullyAndPartialAndNonCoherent, dmrs-Type=1, maxLength =2, rank=7 Table 4: TPMI and Antenna port(s), transform precoder is disabled, codebookStibset = fullvAndPartialAndNonCoherent dmrs-Type=1, maxLength =2, rank=8 0 2 X1 0-7 2 1 2 X2 0-7 2 2 2 X3 0-7 2 3 2 X4 0-7 2 2 0-7 2 2 XM 0-7 2 100851 From the above example tables, it can be seen that the mapping table includes an Value Number of ElmRst,Dm group00 without data 0 2 2 2 3 2 X I 0,1,2.3,4.6 X2 0,1,2.3,4.6 X3 0,1,2.3,4.6 X4 0,1,2,3,4,6 XM 0,1,2,3,4,6 X1 0-6 X2 0-6 X3 0-6 0-6 X4 0-6

XM 0-6

Ntimbcr Of R *,grtt>14P01,1 WM19

TPMI

index, information on TPMI, and corresponding DMRS pork. In addition, it may also include the nuber of DRMS CDM group(s) without data and the nubcr of front-loal syrubol.s 100861 Based on the first configuration information, the terminal device may learn the number of layer or the rank and based on the rank, the terminal device may deteremine a a mapping table corresponding to the number of layers or the rank from the mapping tables corresponding to various ranks. For example, if the first configuration indicates 7 transmission layers and the terminal device may determine to use Table 3 to determine TPMI and DM RS port.

100871 The index value in the table may correspond to the second configuration information. Using the second configuration information, the terminal device may determined the corresponding TMPI and DRMS ports.

100881 In some embodiments, the DMRS port mapping may be fixed according to the rank signaled, which may be: (0-41 for rank 5; (0,1,2,3,4,6) for rank 6; (0-61 for rank 7. and (0-7) for rank 8 ( for DMRS type 1).

(0-3,61 for rank 5, (0-3,6,8) for rank 6, (0-3, 6-8) for rank 7 and (0-3.6-91 for rank 8 (for DMRS type 2).

In such a case" in the mapping tables, only TPMI may be different for different indexes.

[0089] In some embodiments, the size of the table may be determined as for example, 8 or 16 bit according to the number of TPMI used (M). For example, the network device 120 may pre-configure the subset of the TPMI for each rank, and the size of the TPMI for each rank (M) may be separately configured by a RRC message. As an example, size M of the TPMI can be the same or different for different ranks. For example, the DCI size of the "TPMI and Antenna ports" field may be determined by ceiling (log2(max (M ank=5,. .8))) B. Partial-coherent Capability and Codebook Subset.PartialAndNonCoherent 100901 In this example case, it is assumed that the terminal device 110 supporting partial-coherent capability and the terminal device is configured with codebook subset corresponding to Partial AndNonCoherent.

100911 In some example embodiments, the terminal device 120 may receive a second codebook subset configuration for partial and non-coherent, corresponding to the partial-coherent capability. In this case, the at least one mapping table may comprise at least one second mapping table corresponding to the second codebook subset configuration.

100921 For example, the terminal device 110 may report full or partial-coherent capability and the network device 120 may configure the codebookSubset as PartialAndNonCoherent as well. In this case, at least one second mapping table may comprise one or more mappings corresponding to different numbers of transmission layers and codebookSubset. Each may comprise indexes of the second configuration information, and TPMIs, information on antenna ports in respective CDM groups and DMRS ports, respectively corresponding to the indexes.

100931 In other words, the second mapping table may comprise TPMI information, and the layers to DMRS port mapping. The mapping may be fulfilling that the layers associated with a coherent antenna group are mapped to the same CDM group.

100941 For this type of ten tinal device, its partial coherent capability may be identified as a configuration of more than one antenna group. In this case, DMRS port mapping may consider divide coherent ports into the same CDM groups. For example, the antenna ports in the same CDM antenna group may be coherent with each other, and antenna ports in different CDM antenna groups may be not coherent with each other.

100951 In such a case, when the terminal device 110 reports its support for partial coherency, the DMRS port mapping may consider antenna port group mapping. For 8 TX, two types of partial coherent mapping may be considered, i.e., 2 groups of 4TX, and 4 groups of 2 TX. CDM between the same port group may be preferred because they are well time-synchronized. CDM between the different port groups may not be preferred, because non-coherency may break orthogonality between ports. Therefore, for example, layers associated with the antenna ports in the same antenna group may be mapped to the same DMRS CDM group. As used herein, the SRS port group may be used with the same meaning as the antenna group.

100961 Assuming that the coherent group configuration of the teiuiinal device 110 is reported to the network device 120, different antenna port(s) tables may be defined for two different group configurations.

100971 For example, based on the capability of the terminal device 110, it is assumed that SRS antenna ports may be indexed as: - 2 group of 4 TX: 1000+10,1,2,31, 1000+14,5,6,71, or - 4 group of 2 TX: 1000+10,11, 12,31, {4,5}, {6,7} [0098] In some embodiments, a port group selection is supported, the example layer mapping to groups may be provided as follows, for illustrative purposes.

* Regarding 2 group of 4TX [0099] In this case, there are two groups of 4TX, i.e., 1000+10,1,2,31, 1000+14.5,6,71. In some embodiments, the rank, i.e., the transmission layers, may be first divided into 2 groups and mapped into 2 SRS antenna port groups. Then, the SRS ports may be mapped 10 to DMRS ports.

1001001 FIG. 4 illustrates example SRS antenna port group to DMRS CDM group mapping for DMRS type 1. As illustrated in Fig. 4, for 2 group of 4TX, antnan ports ar first divided into two SRS port groups 0 and I. The SRS port groups may mapped to TMP1s, which may be further mapped to DMRS ports of two CDM groups 0 and 1. For 4 group of 2TX, antnan ports are divided into four SRS port groups 0 to 3. The SRS port groups may mapped to TMPIs, which may be further mapped to DMRS ports of two CDM groups 0 and 1. Similar principle may be applied also to the table design for DMRS type 2.

[00101] For illustrative purposes, Tables 5-6 below show example mapping tables (codebookSubset = PartialAndNonCoheren)with different rank values, with the assumption 20 that PUSCH DMRS ports are indexed from 0 to 8 for SU-M1MO. Each row entry of the mapping table may provide both TPM I and layers to SRS ports/DMRS port mapping. As shown in these tables, M is the largest row index of each table.

1001021 The following Table 5 shows an example mapping table for rank 5, also referred to as first mapping table.

Table 5: TPMI and Antenna port(s), transform precoder is disabled, codebookSubset = PartialAtztiNonCoherent, 2 groups with 4TX, dnzrs-Type=1,maxLength=2, rank=5 0 5 layers X1 4 layers 1 layer 0,1,4,5,2 layers X2 4 layers 1 layer 0,1,4,5,2 2 5 layers X3 4 layers I layer 0,1,4,5,2 Slayers 4 layers 1 layer 0,1,4,5,2 Slayers Y1 3 2 0,1,4, 2,3 Slayers Y2 3 2 0,1,4, 2,3 Slayers 3 2 0,1,4,2,3 Slayers W1 2 3 0,1,2,3,6 Slayers W2 2 3 0,1,2,3,6 Slayers 2 3 0,1, 2,3,6 layers Z1 1 4 0, 2,3,6,7 layers Z2 1 4 0, 2,3,6,7 M 5 layers 1 4 0, 2,3,6,7 1001031 As shown in Table 5, the index (that is, the second configuration information) of 2 may indicate that 5 layers are mapped to SRS ports 1000+0,1,2,3 and 1000+4, and they may be further mapped to DMRS ports 0,1,4,5,2 in order. Also, TPMI X2 may he applied for the PUSCH/DMRS transmission. In this case. both TPMI and layers to SRS ports/DMRS port mapping may need to be determined based on the index.

1991041 In addition, Table 6 further shows an example second mapping table for rank 8.

Table 6: TPMI and Antenna port(s), transform preeoder is disabled, codebook,Subset = PartialAndNonCoherent, 2 ffroups with 4TX dnzrs-Type=1, maxLength=2, rank=8 0 X1 4 layers 4 layers 0,1,4,5,2,3,6,7 X2 4 4 0, 1,4,5,2.16,7 2 X3 4 4 0. I.4,5,2,3.6,7 4 4 0, I,4,5,2,16,7 XX 4 4 0,1,4,5,2,3,6,7 1991051 For rank=8, because all SRS and DMRS ports may be mapped to all 8 layers and there is only one manner of antenna port divisions. Therefore, in such a case, only TPMI may be signaled via the index. In other words, in this case, only TPMI may need to be determined based on the second configuration information. In addition, it is also possible does not include a mapping of SRS port to layers in the mapping table.

[00106] Alternatively or additionally. the TPMI may implictly indicate mapping SRS ports to layers, and the information of the fourth and the fifth columns as shown in Tables 5-6 may associated with TPMI. Thus, it is possible to combine TPMI and layers to SRS ports mapping with the TMPI, for example, as shown in Table 7. In this case, the TPMI dimension may be for example [rank]x[8], and the value of 0 may be used to indicate selecting no SRS port for any of the layers.

Table 7: TPAII and Antenna port(s), transform preeoder is disabled, codebook,Subset = PartialAndNonCoherent, 2 groups with 4TX, dmrs-Type=1, maxLength=2, rank=5 * Regarding 4 group of 2TXe [00107] In this case, the number of layers may be first divided into 4 groups, mapped into 4 SRS antenna port groups, and finally mapped to DMRS ports. The 8 antenna port may he divided into 4 group of 2TX, for example, 1000+ (0,1), (2,31, {4,5}, {6,7) [00108] For illustrative purposes. Tables 8-10 below show example second mapping tables with DMRS type=1 for 5 layers. As an example, to distribute groups to 2 CDM groups evenly, the DMRS port mapping order may he swapped, for example, 0,1,2,3,4 or 0,1,4,2,3, etc. [00109] In Table 8, the TPM I may already he embedded with the information of SRS ports to layer mapping, and thus only TPMT and DMRS port mapping may be listed in Table 8.

DMRS ports combination may be different according to the SRS antenna port group selection, such as {0,1,2,3,4}, {0,1,2,6,7} ... {0,2,3,4,5}. As an example, it is allowed to support principles of power balance among CDM groups and mapping the same port group to the same CDM group.

Table 8: TPM1 and Antenna port(s), transform precoder is disabled, code bookSubset = PartialAndNonCoherent, 4,groups with 2TX dmrs-Type=1, maxLength=2, rank=5 0 X1 0,1,2,3,4 1 X2 0,1,2,3,4 2 X3 0,1,2,4,5 X1 X2 X3 X4 0 2,3,6,7 3 X4 0,1,2,4,5 4 0,1,2,6,7 M XM 0,2,3,4,5 1001101 For illustrative purposes. Table 9 shows another example second mapping table with port group to layer mapping for different DMRS port combinations. The port group to layer mapping may be already extracted from the TPMI information. Thus, as another option, the TPMI may be simplified with separate indication of port group to layer mapping as shown in Table 9, with the assumption of always mapping the DM RS ports from port 0.

Table 9: TPMI and Antenna port(s), transform precoder is disabled, codebookSubset = PartialAtidNonCoherent, 4 2roups with 2TX dmrs-Type=1. tnaxLength =2, rank=5 0 XI 2 layers 2 layers I layers 0 layers 0, I 1,14 X2 2 2 0 0,1 1,14 2 X3 2 1 2 0 0,1.2,6.7 3 X4 2 1 0,1 1,14 4 2 0 2 0,11,63 2 0 2 1 0,1.2,3.4 6 2 0 1 2 0,1.4,6.7 7 1 2 2 0 0,2,3,4,5 9 2 0,1 1,14 1 0 2 2 0,2.3,4.5 11 0 2 2 1 0,1.2,3.4 12 0 2 1 2 0,1,2,4,5 13 0 1 2 2 0,2,3,4,5 1001111 As a further example, it s allowed to map the SRS port (1000+x) diectrly to the DMRS port (x), as shown in Table 10.

Table 10: TPMI and Antenna port(s), transform precoder is disabled codebookSubset = PartittlAndiVonCoherent, 4 2roups with 2TX dmrs-Type=1, maxterigth=2, rank=5 0 XX 2 layers 2 layers 1 layers 0 layers 0,1,2,3,4 1 XX 2 2 0 1 0,1,2,3,4 2 XX 2 1 2 0 0,1,2,4,5 3 XX 2 1 1 1 0,1,2,3,4 4 2 1 0 2 0,1,2,6,7 2 0 2 1 0,1",4,5.6 6 2 0 1 2 0,1,4,6,7 7 1 2 2 0 0,2,3,4,5 8 1 2 1 1 0,2,3,4,5 9 1 1 2 1 0,1,2,3,4 1 0 2 2 0.2,3.4,5 I I 0 2 2 I,2,3,4,5,6 12 0 2 I 2,2,3,4,6,7 13 0 1 1 2 2,4,5,6,7

M

1001121 For example, without consideration of the port mapping order, the antenna port group combination may be either (2+2+1) or (2+1+1+1) and the CDM group mapping may be 2+3(2+1) or 2 + 3(1+1+1) respectively.

[00113] In addition e, a similar mapping may be defined for 6,7 and 8 layers: For 6 layers, 2+2+2 or 2+2+1+1 may be supported, and CDM group mapping may be 4(2+2)+2 or 3(2+1)+3(2+1) For 7 layers, 2+2+2+1 may be supported, and CDM group mapping may be 4(2+2) +3 (2+1) For 8 layers, only one DMRS port mapping may be supported [00114] For example, for rank 1-4, the same principle as in case A for coherent cases may be supported for high throughput support, so DMRS ports 0,1,4,5 for type 1 or DM RS ports 0,1,6,7 for type 2 may be supported only.

C. Non-coherent Capability and Codebook Subset.NonCoherent [00115] In this example case, it is assumed that the terminal device 110 supporting non-coherent capability and the terminal device is configured with codebook subset corresponding to NonCoherent.

[00116] In some example embodiments, the terminal device 120 may receive a third codebook subset configuration for non-coherent, corresponding to the non-coherent capability. In this case, the at least one mapping table may comprise at least one third mapping table corresponding to the third codebook subset configuration.

1001171 In this case, the terminal device 110 may report full/partial or non-coherent capability and the network device 120 may configure the codebookSubset as NonCoherent as well. In some embodiments, it is expected that the terminal device 110 may report non-coherent capability.

[00118] For example, the at least one third mapping table each may comprise a bitmap for antenna port selection, which is equivalent to TPM1 and port mapping. For example, for non-coherent 8TX, the mapping table may comprise 8-bit bitmaps. Each bitmap may correspond to the antenna port in order, and any antenna port with a corresponding bit set to "one" may mean that it is selected for the DMRS transmission.

[00119] For example, the selected antenna ports may be mapped to DMRS ports in a fixed order according to the number of layers, and the order may be determined from the sequence of 0,1,2,3,4,6,5,7. For example, if the number of layers is 5, the DMRS ports to be used may be indexed by 0,1,2,3,4. As another example, if the number of layers is 6, the DMRS ports to be used may be indexed by 0,1,2,3,4,6.

[00120] For illustrative purposes, Table 11 below shows an example third mapping table.

Table 11: TPMI and Antenna port(s), transform precoder is disabled codebookSubset = NonCoherent dmrs-Type=1, maxLength=2, rank=5, 8TX [00121] As another example, the teii tinal device 110 may receive a bitmap for transmission layer indication, antenna port selection and DRMS port mapping, instead of the antenna port configuration information comprising at least first configuration 25 information and second configuration information. Then, the terminal device may 14OR:Si: 1 1 1 10010 1 1 1 10001

XM

determine die antenna port configuration based on the bitmap.

1001221 In this case, instead of receiving the number of layers and TPMI/Antenna ports, it is allowed to receive only one 8-bit bitmap. Each bitmap may correspond to the antenna ports in order, and an antenna port with the corresponding bit set to "one" may mean that it is selected for the DMRS transmission. For example, the number of "1" may correspond to the number of layers, and the antenna ports may he mapped to DMRS ports in order of 0,1,2,3,4,6,5,7.

[00123] As a further example, when the number of layers is smaller than 5, it is allowed to consider the mapping order of 0,1,4,5. The second mapping may he supported when higher UL throughput is needed. The up to 4 layers may be mapped to CDM group 0 only. And the remaining resources for CDM group 1 may be used for PUSCH data transmission. To select one of two mappings, the terminal device 110 may be configured with a separate signal, for example, "DM RS order= f TypeO(Power boosting) or Typel(Throughput)r. Alternatively or additionally, 1-bit DCI may be included to indicate the order.

[00124] As an example, when the network device 120 may indicate layers, according to the configured options among two options, the terminal device 110 may automatically map SRS ports to DMRS ports in order.

[00125] As mentioned hereinabove, in Rd-18, 8TX coherent PUSCH antenna port configuration is expected to be more complex than the legacy configuration (that is, 4 antenna ports). By using of the capability reporting, the concept of a coherent group may be taken in designing a signaling table. Therefore, it is possible to enable the terminal devicd to use different mapping tables, which might reduce the complixitiy in the antenna port configuration and thus improve the system performance.

[00126] FIG. 5 shows a flowchart of an example method 500 implemented at a network 25 device (for example, the network device 120) in accordance with some embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the network device 120 with reference to FIG. 1.

[00127] At block 510, the network device 120 obtains antenna port configuration information. The antenna port configuration information may comprise at least first configuration information and second configuration information. The first configuration information may indicate a number of transmission layers. The second configuration information may indicate at least one of: a transmitted precoding matrix indicator, TPMI, or antenna port information.

1001281 At block 520, the network device 120 transmits, to a terminal device 110, the antenna port configuration information. Then, the antenna port configuration information may used by the terminal device 110 to determine an antenna port configuration to be used for an uplink reference signal. For example, the uplink reference signal may comprise a

DMRS

[00129] In some example embodiments, the network device 120 may determine the antenna port configuration information based on at least one mapping table. The least one mapping table has been described in detail with reference to FIG.2 to FIG. 4 and Tables 1 to 12, Thus, for the purpose of simplification, the details will be omitted.

[00130] In some example embodiments, the network device 120 may receive, from the terminal device 110, an antenna port coherency capability of the terminal device 110. Then, the network device 120 may transmit, to the terminal device 110, a codebook subset configuration. In some example embodiments, the antenna port coherency capability may comprise one or more of: full-coherent capability, partial-coherent capability, or non-coherent capability.

[00131] In some example embodiments, the network device 120 may transmit a first codebook subset configuration for fully, partial and non-coherent, corresponding to the full-coherent capability. In some other example embodiments, the network device 120 may transmit a second codebook subset configuration for partial and non-coherent, corresponding to the partial-coherent capability. Alternatively or additionally the network device 120 may transmit a third codebook subset configuration for non-coherent, corresponding to the non-coherent capability.

[00132] In some example embodiments, the antenna port configuration information may be indicated by at least 4 bits. The first configuration information may be indicated by at least 2 bits. The second configuration information may be indicated by at least 1 bit. The bit length used to indicate the antenna port configuration information has been described in detail with reference to F10.2, thus, for the purpose of simplification, the details will be omitted.

[00133] In some embodiments, an apparatus capable of performing any of operations of the method 200 (for example, the terminal device 110) may include means for performing the respective steps of the method 200. The means may be implemented in any suitable form.

For example, the means may be implemented in a circuitry or software module.

1001341 In some example embodiments, the apparatus may include means for receiving, from a network device, antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPME, or antenna port information; and means for determining an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.

1001351 In some example embodiments, the means for determining the antenna port configuration may comprise: means for determining at least one mapping table associated with the second configuration information based on the first configuration information, the at least one of the TPMI and the antenna port information is determined based on the at least one mapping table and the second configuration information. In some example embodiments, the apparatus may further comprise means for obtaining an ordering of selection of uplink reference signal transmission ports corresponding to the number of transmission layers indicated by the first configuration information based on the at least one mapping table.

MIN In some example embodiments, the apparatus may further comprise means for transmitting, to the network device, antenna port coherency capability of the terminal device; and/or means for receiving, from the network device, a codebook subset configuration. In some example embodiments, the means for deteimining an antenna port configuration to be used may comprise: means for determining the at least one of the TPMI or the antenna port information based on the first configuration information, the second configuration information and the codebook subset configuration.

1001371 In some example embodiments, the the antenna port coherency capability may comprise one of a group compiising one or more of: full-coherent capability, partial-coherent capability, or non-coherent capability.

1001381 In some example embodiments, the means for receiving a codebook subset configuration may comprise one of: receiving a first codebook subset configuration for fully, partial and non-coherent, corresponding to the full-coherent capability; receiving a second codebook subset configuration for partial and non-coherent, corresponding to the partial-coherent capability; or receiving a third codebook subset configuration for non-coherent, corresponding to the non-coherent capability, at least one mapping table is associated with the second configuration information. In such a case, the at least one mapping table may comprise one or more of: at least one first mapping table corresponding to the first codebook subset configuration; at leas( one second mapping table corresponding to the second codebook subset configuration; or at least one third mapping table corresponding to the third codebook subset configuration.

[00139] In some example embodiments, the at leas( one first mapping table may comprise one or more mapping tables corresponding to different numbers of transmission layer, each 10 comprising: indexes of the second configuration information, and TPMIs and demodulation reference signal, DMRS, ports respectively corresponding to the indexes.

[00140] In some example embodiments, the at least one second mapping table may comprise one or more mappings corresponding to different numbers of transmission layer, each comprising: indexes of the second configuration information, and TPMIs, information on antenna ports in respective code division multiplexing. CDM, groups and DMRS ports, respectively corresponding to the indexes, and the antenna ports in the same antenna group are coherent with each other, and antenna ports in different antenna groups are not coherent with each other, and layers associated with the antenna ports in the same antenna group are mapped to the same DMRS CDM group.

[00141] In some example embodiments, the at least one third mapping table each comprises a bitmap for antenna port selection and DRMS port mapping. In some example embodiments, the third codebook subset configuration for non-coherent, corresponding to the non-coherent capability is received from the network device, and the apparatus further comprises means for receiving a bitmap for transmission layer indication, antenna port selection and DRMS port mapping, instead of the antenna port configuration information comprising at least firs( configuration information and second configuration information; and means for determining the antenna port configuration based on the bitmap.

1001421 In some example embodiments, at least one mapping table is associated with the second configuration information, and the at leas( one mapping table comprises a first mapping for uplink reference signal power boosting and a second mapping for increasing uplink throughput.

1001431 In some example embodiments, the uplink reference signal comprises a demodulation reference signal. DMRS.

1001441 In some example embodiments, the antenna port configuration information is indicated by at least 4 bits, and the first configuration information is indicated by at least 2 bits and the second configuration information is indicated by at least 1 bit.

[00145] in some embodiments, an apparatus capable of performing any of the method 500 (for example, the network device 120) may include means for performing the respective steps of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[00146] In some embodiments, the apparatus may further include means for obtaining antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of: a transmitted precoding matrix indicator, TPMI, or antenna port information; and means for transmitting, to a terminal device, the antenna port configuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to be used for an uplink reference signal.

[00147] In some embodiments, the apparatus further comprises means for receiving, from the terminal device, antenna port coherency capability of the terminal device; and means for transmitting, to the terminal device, a codcbook subset configuration.

1001481 In some embodiments, the antenna port coherency capability comprises one or more of: full-coherent capability, partial-coherent capability, or non-coherent capability.

[00149] In some embodiments, the means for transmitting a codebook subset configuration comprises one of: means for transmitting a first codebook subset configuration for fully, partial and non-coherent, corresponding to the full-coherent capability; means for transmitting a second codebook subset configuration for partial and non-coherent, corresponding to the partial-coherent capability; or means for transmitting a third codebook subset configuration for non-coherent, corresponding to the non-coherent capability [00150] In some embodiments,the uplink reference signal comprises a demodulation reference signal, DMRS.

[00151] In some embodiments, the antenna port configuration information is indicated by at least 4 bits, and wherein the first configuration information is indicated by at least 2 bits and the second configuration information is indicated by at least 1 bit.

1001521 FIG. 6 is a simplified block diagram of a device 600 that is suitable for implementing embodiments of the present disclosure. The device 600 may be provided to implement the communication device, for example the terminal device 110 or the network device 120 as shown in FIG. 1. As shown, the device 600 includes one or more processors 610, one or more memories 640 coupled to the processor 610, and one or more transmitters and/or receivers (TX/RX) 640 coupled to the processor 610.

[00153] The TX/RX 640 is for bidirectional communications. The TXJRX 640 has at least one antenna to facilitate communication. The communication interface may 10 represent any interface that is necessary for communication with other network elements.

[00154] The processor 610 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 600 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[00155] The memory 620 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) 624, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 622 and other volatile memories that will not last in the power-down duration.

[00156] A computer program 630 includes computer executable instructions that are 25 executed by the associated processor 610. The program 630 may be stored in the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

[00157] The embodiments of the present disclosure may be implemented by means of the program so that the device 600 may perform any process of the disclosure as discussed with reference to FIGs. 2 to 5. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[00158] In some embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD. DVD, and the like. FIG. 7 shows an example of the computer readable medium 700 in form of CD or DVD The computer readable medium has the program 630 stored thereon.

[00159] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

1001601 The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method 200 or 500 as described above with reference to FIG. 2 and FIG. 5. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[00161] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

1001621 In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[00163] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. The term "non-transitory," as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[00164] Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

1001651 Although the present disclosure has been desciibed 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: I. A terminal device, comprising: one or more transceivers; and one or more processors communicatively coupled to the one or more transceivers, wherein the one or more processors are configured to cause the terminal device to: receive, from a network device, antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precodin2 matrix indicator, TPMI, or antenna port information; and determine an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.
2. The terminal device of claim I. wherein the terminal device is caused to determine the antenna port configuration by: determining at least one mapping table associated with the second configuration information based on the first configuration information, and wherein the at least one of the TPMI and the antenna port information is determined based on the at least one mapping table and the second configuration information.
3. The terminal device of claim 2, wherein the terminal device is further caused to: obtain an ordering of selection of uplink reference signal transmission ports corresponding to the number of transmission layers indicated by the first configuration information based on the at least one mapping table.
4. The terminal device of any of claims 1-3, wherein the terminal device is further caused to: transmit, to the network device, an antenna port coherency capability of the terminal device; and/or receive, from the network device, a codebook subset configuration.
5. The terminal device of claim 4, wherein the terminal device is further caused to determine an antenna port configuration to be used by: determining the at least one of the TPMI or the antenna port information based on the first configuration information, the second configuration information and the codebook subset configuration.
6. The terminal device of claim 4 or 5, wherein the antenna port coherency capability comprises one of a group comprising one or more of: full-coherent capability, partial-coherent capability, or non-coherent capability.
7. The terminal device of any of claims 4-6, wherein the terminal device is caused to receive a codebook subset configuration by one of: receiving a first codebook subset configuration for fully, partial and non-coherent, corresponding to the full-coherent capability; receiving a second codebook subset configuration for partial and non-coherent, corresponding to the partial-coherent capability; or receiving a third codebook subset configuration for non-coherent, corresponding to the non-coherent capability, and wherein at least one mapping table is associated with the second configuration information, and the at least one mapping table comprises one or more of: at least one first mapping table corresponding to the first codebook subset configuration; at least one second mapping table corresponding to the second codebook subset configuration; or at least one third mapping table corresponding to the third codebook subset configuration.
8. The terminal device of claim 7, wherein the at least one first mapping table comprises one or more mapping tables corresponding to different numbers of transmission layers, each comprising: indexes of the second configuration information, and TPMIs and demodulation reference signal. DMRS, ports respectively corresponding to the indexes.
9. The terminal device of claim 7, wherein the at least one second mapping table comprises one or more mappings corresponding to different numbers of transmission layers, each comprising: indexes of the second configuration information, and TPMIs, information on antenna ports in respective code division multiplexing, 5 CDM, groups and DMRS ports, respectively corresponding to the indexes, and wherein the antenna ports in the same antenna group are coherent with each other, and antenna ports in different antenna groups are not coherent with each other, and wherein layers associated with the antenna ports in the same antenna group are mapped to the same DMRS CDM group.
10. The terminal device of claim 7, wherein the at least one third mapping table each comprises a bitmap for antenna port selection and DRMS port mapping.
11. The terminal device of any of claims 7 to 10, wherein the third codebook subset configuration for non-coherent corresponding to the non-coherent capability is received from the network device, and wherein the terminal device is further caused to: receive a bitmap for transmission layer indication, antenna port selection and DRMS port mapping, instead of the antenna port configuration information comprising at least first configuration information and second configuration information; and determine the antenna port configuration based on the bitmap.
12. The terminal device of any of claims 1-11, wherein at least one mapping table is associated with the second configuration information, and wherein the at least one mapping table comprises a first mapping for uplink reference signal power boosting and a second mapping for increasing uplink throughput.
13. The terminal device of any of claims 1-12, wherein the uplink reference signal comprises a demodulation reference signal, DMRS.
14. The terminal device of any of claims 1-13, wherein the antenna port configuration information is indicated by at least 4 bits, and wherein the first configuration information is indicated by at least 2 bits and the second configuration information is indicated by at least 1 bit.
15. A network device, comprising: one or more transceivers; and one or more processors communicatively coupled to the one or more transceivers, wherein the one or more processors are configured to cause the network device to: obtain antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of: a transmitted precoding matrix indicator, TPIVIE, or antenna port information; and transmit, to a terminal device, the antenna port configuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to be used for an uplink reference signal.
16. The network device of claim 15, wherein the network device is further caused to: receive, from the terminal device, an antenna port coherency capability of the terminal device; and transmit, to the terminal device, a codebook subset configuration.
17. The network device of claim 16, wherein the antenna port coherency capability comprises one or more of: full-coherent capability, partial-coherent capability, or non-coherent capability.
18. The network device of claim 16 or 17, wherein the network device is caused to transmit a codebook subset configuration by one of: transmitting a first codebook subset configuration for fully, partial and non-coherent, corresponding to the full-coherent capability; transmitting a second codebook subset configuration for partial and non-coherent, corresponding to the partial-coherent capability; or transmitting a third codebook subset configuration for non-coherent, corresponding to the non-coherent capability
19. The network device of any of claims 15-18, wherein the uplink reference signal comprises a demodulation reference signal, DMRS.
20. The network device of any of claims 15-19, wherein the antenna port configuration information is indicated by at least 4 bits, and wherein the first configuration information is indicated by at least 2 bits and the second configuration information is indicated by at least 1 bit
21. A method at a terminal device, comprising: receiving, from a network device, antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPMI, or antenna port information; and determining an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.
22. A method at a network device, comprising: obtaining antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of: a transmitted precoding matrix indicator, TPMI, or antenna port information; and transmitting, to a terminal device, the antenna port configuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to be used for an uplink reference signal.
23. An apparatus of a terminal device, comprising: means for receiving, from a network device, antenna port configuration information comprising at least first configuration information and second configuration information.wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPMI, or antenna port information; and means for determining an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.
24. An apparatus of a network device, comprising: means for obtaining antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of: a transmitted precoding matrix indicator, TPMI, or antenna port information; and means for transmitting, to a terminal device, the antenna port configuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to be used for an uplink reference signal.
25. A terminal device, comprising: at least one processor; and at least one memory including computer program codes, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to: receive, from a network device, antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of a transmitted precoding matrix indicator, TPMI, or antenna port information; and determine an antenna port configuration to be used for an uplink reference signal based on the antenna port configuration information.
26. A network device, comprising: at least one processor; and at least one memory including computer program codes, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to: obtain antenna port configuration information comprising at least first configuration information and second configuration information, wherein the first configuration information indicates a number of transmission layers, and wherein the second configuration information indicates at least one of: a transmitted precoding matrix indicator, TPMI, or antenna port information; and transmit, to a terminal device, the antenna port confiuration information, wherein the antenna port configuration information is used to determine an antenna port configuration to he used for an uplink reference signal.
27. A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of Claim 21 or 22.