WO2023208444A1

WO2023208444A1 - Method for uplink repetition

Info

Publication number: WO2023208444A1
Application number: PCT/EP2023/054485
Authority: WO
Inventors: Alessio MARCONE; Majed SAAD; Frank Frederiksen; Rafhael MEDEIROS DE AMORIM
Original assignee: Nokia Technologies Oy
Priority date: 2022-04-29
Filing date: 2023-02-23
Publication date: 2023-11-02

Abstract

An apparatus comprising: means for obtaining a configuration from a network element, the configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; means for grouping, according to said configuration, the number of transmissions in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets; and means for using the grouping of the number of transmissions based on said allocation of symbols for transmitting on said physical uplink channel.

Description

METHOD FOR UPLINK REPETITION

TECHNICAL FIELD

[0001] The present invention relates to uplink repetition schemes.

BACKGROUND

[0002] One of the new service categories introduced in 5G NR networks is ultra-reliable low-latency communication (URLLC). 3 GPP Release 15 and 16 versions of the 5G standard have built the physical implementation of URLLC to meet the two conflicting requirements of reliability and latency.

[0003] 3GPP Release 15 introduced a slot-based transmission of OFDM symbols of a packet for Physical Uplink Shared Channels (PUSCH) referred to as repetition Type A, where PUSCH repetition via slot aggregation was supported in a semi-static way, i.e. no repetition within a slot. Therein, to avoid transmitting a long PUSCH across slot boundary, the user equipment (UE) may transmit (small) PUSCHs in several repetitions in the consecutive available slots. For further reducing latency, 3GPP Release 16 introduced PUSCH repetition Type B, where a transport block is scheduled allowing cross-slot- boundary and cross-DL-symbols repetitions.

[0004] Demodulation Reference Signal (DMRS) bundling is a feature that has been introduced in 3 GPP Release 17, aiming at improving channel estimation accuracy by bundling DMRS of PUSCH/PUCCH transmissions across different slots. Nevertheless, in many practical scenarios, channel conditions evolve very rapidly, and application of the coverage enhancements feature DMRS bundling becomes very challenging. In such scenarios, the coherence time of the channel may typically be very small, whereupon using PUSCH repetition Type A (a number of OFDM symbols within one slot) may not be sufficient for accurate channel estimation. On the other hand, if using PUSCH repetition Type B (a number of OFDM symbols extending across multiple slots) for DMRS bundling, the UE may have challenges to maintain the phase continuity, while maintaining good time and frequency pre-compensation across multiple slots. SUMMARY

[0005] Now, an improved method and technical equipment implementing the method has been invented, by which the above problems are alleviated. Various aspects include a method, an apparatus and a non-transitory computer readable medium comprising a computer program, or a signal stored therein, which are characterized by what is stated in the independent claims. Various details of the embodiments are disclosed in the dependent claims and in the corresponding images and description.

[0006] The scope of protection sought for various embodiments of the invention is set out by the independent claims. The embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the invention.

[0007] According to a first aspect, there is provided an apparatus comprising means for obtaining a configuration from a network element, the configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; means for grouping, according to said configuration, the number of transmissions in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets; and means for using the grouping of the number of transmissions based on said allocation of symbols for transmitting on said physical uplink channel.

[0008] According to an embodiment, the physical uplink channel is Physical Uplink Shared Channel (PUSCH) or Physical Uplink Control Channel (PUCCH).

[0009] According to an embodiment, the grouping of the number of transmissions is either predetermined or based on one or more parameters of said configuration, the parameters including at least one of a number of consecutive transmissions in a subset and a length of the gap between the subsets.

[0010] According to an embodiment, the apparatus comprises means for determining the gap between subsets of transmissions based on the allocation of symbols and on the grouping of the number of transmissions.

[0011] According to an embodiment, the number of transmissions to be grouped as subsets is two, and the allocation of the symbols in every other slot, starting from a first slot, comprises a number of symbols in an end of the slot and the allocation of the symbols in alternating slots, starting from a second slot, comprises a number of symbols in a beginning of the slot.

[0012] According to an embodiment, the transmission on the physical uplink channel comprises demodulation reference signals (DMRS) for demodulation of the physical uplink channel at a receiver.

[0013] According to an embodiment, the apparatus comprises means for obtaining, from the network element, a first indication with an allocation of the symbols across the plurality of slots for the transmission of a Physical Uplink Shared Channel (PUSCH) Type A repetition; and means for obtaining, within the configuration from the network element, a second indication to change the allocation of symbols, according to which said means for grouping the number of transmissions is configured to group, according to said configuration, a number of PUSCH repetitions in a first subset and a number of PUSCH repetitions in a second subset, wherein a first PUSCH repetition of the first and second subset is in the same slot and symbols, in time- wise order, as the corresponding PUSCH repetition in the PUSCH Type A repetition.

[0014] According to an embodiment, the apparatus comprising means for changing an order of the symbols in every other slot, starting from the second slot, to be opposite to their original time-wise order.

[0015] A method according to a second aspect comprises obtaining, by a user equipment, a configuration from a network element, the configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; grouping, according to said configuration, the number of transmissions in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets; and using, by the user equipment, the grouping of the number of transmissions based on said allocation of symbols for transmitting on said physical uplink channel.

[0016] An apparatus according to a third aspect comprises means for providing a user equipment with a configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; and means for receiving, from the user equipment, transmissions on said physical uplink channel, wherein the number of transmissions are grouped in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets.

[0017] A method according to a fourth aspect comprises providing, by a network element, a user equipment with a configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; and receiving, from the user equipment, transmissions on said physical uplink channel, wherein the number of transmissions are grouped in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets.

[0018] Computer readable storage media according to further aspects comprise code for use by an apparatus, which when executed by a processor, causes the apparatus to perform the above methods.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] For a more complete understanding of the example embodiments, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:

[0020] Fig. 1 shows a schematic block diagram of an apparatus for incorporating a dual- SIM/MUSIM arrangement according to the embodiments;

[0021] Fig. 2 shows schematically a layout of an apparatus according to an example embodiment;

[0022] Fig. 3 shows a part of an exemplifying radio access network;

[0023] Figs. 4a and 4b show examples of segmentation of nominal repetitions in PUSCH Repetition Type B;

[0024] Fig. 5 shows an example of applying invalid symbol patterns;

[0025] Fig. 6 shows an example of PUSCH repetitions Type A with small number of allocated OFDM symbols combined with DMRS bundling; [0026] Fig. 7 shows a flow chart for an enhanced uplink repetition scheme in a user equipment according to an embodiment;

[0027] Figs. 8a and 8b show an example illustrating differences between a conventional PUSCH Type A repetition and the enhanced type of repetition according to an embodiment;

[0028] Fig. 9 shows an example of the enhanced type of repetition according to an embodiment;

[0029] Fig. 10 shows a signalling chart for applying the enhanced uplink repetition scheme according to an embodiment;

[0030] Fig. 11 shows an example of the enhanced type of repetition according to another embodiment; and

[0031] Fig. 12 shows a flow chart for applying the enhanced uplink repetition scheme in a network element according to an embodiment.

DETAILED DESCRIPTON OF SOME EXAMPLE EMBODIMENTS

[0032] The following describes in further detail suitable apparatus and possible mechanisms carrying out uplink repetition schemes. While the following focuses on 5G networks, the embodiments as described further below are by no means limited to be implemented in said networks only, but they are applicable in any network supporting uplink repetition schemes.

[0033] In this regard, reference is first made to Figures 1 and 2, where Figure 1 shows a schematic block diagram of an exemplary apparatus or electronic device 50, which may incorporate the arrangement according to the embodiments. Figure 2 shows a layout of an apparatus according to an example embodiment. The elements of Figs. 1 and 2 will be explained next.

[0034] The electronic device 50 may for example be a mobile terminal or user equipment of a wireless communication system. The apparatus 50 may comprise a housing 30 for incorporating and protecting the device. The apparatus 50 further may comprise a display 32 and a keypad 34. Instead of the keypad, the user interface may be implemented as a virtual keyboard or data entry system as part of a touch-sensitive display. [0035] The apparatus may comprise a microphone 36 or any suitable audio input which may be a digital or analogue signal input. The apparatus 50 may further comprise an audio output device, such as anyone of: an earpiece 38, speaker, or an analogue audio or digital audio output connection. The apparatus 50 may also comprise a battery 40 (or the device may be powered by any suitable mobile energy device such as solar cell, fuel cell or clockwork generator). The apparatus may further comprise a camera 42 capable of recording or capturing images and/or video. The apparatus 50 may further comprise an infrared port 41 for short range line of sight communication to other devices. In other embodiments the apparatus 50 may further comprise any suitable short-range communication solution such as for example a Bluetooth wireless connection or a USB/firewire wired connection.

[0036] The apparatus 50 may comprise a controller 56 or processor for controlling the apparatus 50. The controller 56 may be connected to memory 58 which may store both user data and instructions for implementation on the controller 56. The memory may be random access memory (RAM) and/or read only memory (ROM). The memory may store computer-readable, computer-executable software including instructions that, when executed, cause the controller/processor to perform various functions described herein. In some cases, the software may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein. The controller 56 may further be connected to codec circuitry 54 suitable for carrying out coding and decoding of audio and/or video data or assisting in coding and decoding carried out by the controller.

[0037] The apparatus 50 may comprise radio interface circuitry 52 connected to the controller and suitable for generating wireless communication signals for example for communication with a cellular communications network, a wireless communications system or a wireless local area network. The apparatus 50 may further comprise an antenna 44 connected to the radio interface circuitry 52 for transmitting radio frequency signals generated at the radio interface circuitry 52 to other apparatus(es) and for receiving radio frequency signals from other apparatus(es).

[0038] In the following, different exemplifying embodiments will be described using, as an example of an access architecture to which the embodiments may be applied, a radio access architecture based on Long Term Evolution Advanced (LTE Advanced, LIE- A) or new radio (NR, 5G), without restricting the embodiments to such an architecture, however. A person skilled in the art appreciates that the embodiments may also be applied to other kinds of communications networks having suitable means by adjusting parameters and procedures appropriately. Some examples of other options for suitable systems are the universal mobile telecommunications system (UMTS) radio access network (UTRAN or E-UTRAN), long term evolution (LTE, the same as E-UTRA), wireless local area network (WLAN or WiFi), worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, sensor networks, mobile ad-hoc networks (MANETs) and Internet protocol multimedia subsystems (IMS) or any combination thereof.

[0039] Figure 3 depicts examples of simplified system architectures only showing some elements and functional entities, all being logical units, whose implementation may differ from what is shown. The connections shown in Figure 3 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that the system typically comprises also other functions and structures than those shown in Figure 3. The embodiments are not, however, restricted to the system given as an example but a person skilled in the art may apply the solution to other communication systems provided with necessary properties.

[0040] The example of Figure 3 shows a part of an exemplifying radio access network. [0041 ] Figure 3 shows user devices 300 and 302 configured to be in a wireless connection on one or more communication channels in a cell with an access node (such as (e/g)NodeB) 304 providing the cell. The physical link from a user device to a (e/g)NodeB is called uplink or reverse link and the physical link from the (e/g)NodeB to the user device is called downlink or forward link. It should be appreciated that (e/g)NodeBs or their functionalities may be implemented by using any node, host, server or access point etc. entity suitable for such a usage.

[0042] A communication system typically comprises more than one (e/g)NodeB in which case the (e/g)NodeBs may also be configured to communicate with one another over links, wired or wireless, designed for the purpose. These links may be used for signaling purposes. The (e/g)NodeB is a computing device configured to control the radio resources of communication system it is coupled to. The NodeB may also be referred to as a base station, an access point or any other type of interfacing device including a relay station capable of operating in a wireless environment. The (e/g)NodeB includes or is coupled to transceivers. From the transceivers of the (e/g)NodeB, a connection is provided to an antenna unit that establishes bi-directional radio links to user devices. The antenna unit may comprise a plurality of antennas or antenna elements. The (e/g)NodeB is further connected to core network 310 (CN or next generation core NGC). Depending on the system, the counterpart on the CN side can be a serving gateway (S-GW, routing and forwarding user data packets), packet data network gateway (P-GW), for providing connectivity of user devices (UEs) to external packet data networks, or mobile management entity (MME), etc. The CN may comprise network entities or nodes that may be referred to management entities. Examples of the network entities comprise at least an Access and Mobility Management Function (AMF).

[0043] The user device (also called a user equipment (UE), a user terminal, a terminal device, a wireless device, a mobile station (MS) etc.) illustrates one type of an apparatus to which resources on the air interface are allocated and assigned, and thus any feature described herein with a user device may be implemented with a corresponding network apparatus, such as a relay node, an eNB, and an gNB. An example of such a relay node is a layer 3 relay (self-backhauling relay) towards the base station.

[0044] The user device typically refers to a portable computing device that includes wireless mobile communication devices operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: a mobile station (mobile phone), smartphone, personal digital assistant (PDA), handset, device using a wireless modem (alarm or measurement device, etc.), laptop and/or touch screen computer, tablet, game console, notebook, and multimedia device. It should be appreciated that a user device may also be a nearly exclusive uplink only device, of which an example is a camera or video camera loading images or video clips to a network. A user device may also be a device having capability to operate in Internet of Things (loT) network which is a scenario in which objects are provided with the ability to transfer data over a network without requiring human-to-human or human-to- computer interaction. Accordingly, the user device may be an loT-device. The user device may also utilize cloud. In some applications, a user device may comprise a small portable device with radio parts (such as a watch, earphones or eyeglasses) and the computation is carried out in the cloud. The user device (or in some embodiments a layer 3 relay node) is configured to perform one or more of user equipment functionalities. The user device may also be called a subscriber unit, mobile station, remote terminal, access terminal, user terminal or user equipment (UE) just to mention but a few names or apparatuses.

[0045] Various techniques described herein may also be applied to a cyber-physical system (CPS) (a system of collaborating computational elements controlling physical entities). CPS may enable the implementation and exploitation of massive amounts of interconnected ICT devices (sensors, actuators, processors microcontrollers, etc.) embedded in physical objects at different locations. Mobile cyber physical systems, in which the physical system in question has inherent mobility, are a subcategory of cyberphysical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals.

[0046] Additionally, although the apparatuses have been depicted as single entities, different units, processors and/or memory units (not all shown in Fig. 1) may be implemented.

[0047] 5G enables using multiple input - multiple output (MIMO) antennas, many more base stations or nodes than the LTE (a so-called small cell concept), including macro sites operating in co-operation with smaller stations and employing a variety of radio technologies depending on service needs, use cases and/or spectrum available. The access nodes of the radio network form transmission/reception (TX/Rx) points (TRPs), and the UEs are expected to access networks of at least partly overlapping multi-TRPs, such as macro-cells, small cells, pico-cells, femto-cells, remote radio heads, relay nodes, etc. The access nodes may be provided with Massive MIMO antennas, i.e. very large antenna array consisting of e.g. hundreds of antenna elements, implemented in a single antenna panel or in a plurality of antenna panels, capable of using a plurality of simultaneous radio beams for communication with the UE. The UEs may be provided with MIMO antennas having an antenna array consisting of e.g. dozens of antenna elements, implemented in a single antenna panel or in a plurality of antenna panels. Thus, the UE may access one TRP using one beam, one TRP using a plurality of beams, a plurality of TRPs using one (common) beam or a plurality of TRPs using a plurality of beams.

[0048] The 4G/LTE networks support some multi-TRP schemes, but in 5G NR the multi-TRP features are enhanced e.g. via transmission of multiple control signals via multi- TRPs, which enables to improve link diversity gain. Moreover, high carrier frequencies (e.g., mmWaves) together with the Massive MIMO antennas require new beam management procedures for multi-TRP technology.

[0049] 5G mobile communications supports a wide range of use cases and related applications including video streaming, augmented reality, different ways of data sharing and various forms of machine type applications (such as (massive) machine-type communications (mMTC), including vehicular safety, different sensors and real-time control. 5G is expected to have multiple radio interfaces, namely below 6GHz, cmWave and mmWave, and also capable of being integrated with existing legacy radio access technologies, such as the LTE. Integration with the LTE may be implemented, at least in the early phase, as a system, where macro coverage is provided by the LTE and 5G radio interface access comes from small cells by aggregation to the LTE. In other words, 5G is planned to support both inter-RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz - cmWave, below 6GHz - cmWave - mmWave). One of the concepts considered to be used in 5G networks is network slicing in which multiple independent and dedicated virtual sub-networks (network instances) may be created within the same infrastructure to run services that have different requirements on latency, reliability, throughput and mobility.

[0050] Frequency bands for 5G NR are separated into two frequency ranges: Frequency Range 1 (FR1) including sub-6 GHz frequency bands, i.e. bands traditionally used by previous standards, but also new bands extended to cover potential new spectrum offerings from 410 MHz to 7125 MHz, and Frequency Range 2 (FR2) including frequency bands from 24.25 GHz to 52.6 GHz. Thus, FR2 includes the bands in the mmWave range, which due to their shorter range and higher available bandwidth require somewhat different approach in radio resource management compared to bands in the FR1.

[0051] The current architecture in LTE networks is fully distributed in the radio and fully centralized in the core network. The low latency applications and services in 5G require to bring the content close to the radio which leads to local break out and multiaccess edge computing (MEC). 5G enables analytics and knowledge generation to occur at the source of the data. This approach requires leveraging resources that may not be continuously connected to a network such as laptops, smartphones, tablets and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content in close proximity to cellular subscribers for faster response time. Edge computing covers a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, cooperative distributed peer-to-peer ad hoc networking and processing also classifiable as local cloud/fog computing and grid/mesh computing, dew computing, mobile edge computing, cloudlet, distributed data storage and retrieval, autonomic self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and/or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications).

[0052] The communication system is also able to communicate with other networks, such as a public switched telephone network or the Internet 312, or utilize services provided by them. The communication network may also be able to support the usage of cloud services, for example at least part of core network operations may be carried out as a cloud service (this is depicted in Fig. 3 by “cloud” 314). The communication system may also comprise a central control entity, or a like, providing facilities for networks of different operators to cooperate for example in spectrum sharing.

[0053] Edge cloud may be brought into radio access network (RAN) by utilizing network function virtualization (NFV) and software defined networking (SDN). Using edge cloud may mean access node operations to be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head or base station comprising radio parts. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. Application of cloudRAN architecture enables RAN real time functions being carried out at the RAN side (in a distributed unit, DU) and non-real time functions being carried out in a centralized manner (in a centralized unit, CU 308).

[0054] It should also be understood that the distribution of labor between core network operations and base station operations may differ from that of the LTE or even be non- existent. Some other technology advancements probably to be used are Big Data and all-IP, which may change the way networks are being constructed and managed. 5G (or new radio, NR) networks are being designed to support multiple hierarchies, where MEC servers can be placed between the core and the base station or nodeB (gNB). It should be appreciated that MEC can be applied in 4G networks as well. The gNB is a next generation Node B (or, new Node B) supporting the 5G network (i.e., the NR).

[0055] 5G may also utilize non-terrestrial nodes 306, e.g. access nodes, to enhance or complement the coverage of 5G service, for example by providing backhauling, wireless access to wireless devices, service continuity for machine-to-machine (M2M) communication, service continuity for Internet of Things (loT) devices, service continuity for passengers on board of vehicles, ensuring service availability for critical communications and/or ensuring service availability for future railway/maritime/aeronautical communications. The non-terrestrial nodes may have fixed positions with respect to the Earth surface or the non-terrestrial nodes may be mobile nonterrestrial nodes that may move with respect to the Earth surface. The non-terrestrial nodes may comprise satellites and/or HAPSs. Satellite communication may utilize geostationary earth orbit (GEO) satellite systems, but also low earth orbit (LEO) satellite systems, in particular mega-constellations (systems in which hundreds of (nano)satellites are deployed). Each satellite in the mega-constellation may cover several satellite-enabled network entities that create on-ground cells. The on-ground cells may be created through an on-ground relay node 304 or by a gNB located on- ground or in a satellite.

[0056] A person skilled in the art appreciates that the depicted system is only an example of a part of a radio access system and in practice, the system may comprise a plurality of (e/g)NodeBs, the user device may have an access to a plurality of radio cells and the system may comprise also other apparatuses, such as physical layer relay nodes or other network elements, etc. At least one of the (e/g)NodeBs or may be a Home(e/g)nodeB. Additionally, in a geographical area of a radio communication system a plurality of different kinds of radio cells as well as a plurality of radio cells may be provided. Radio cells may be macro cells (or umbrella cells) which are large cells, usually having a diameter of up to tens of kilometers, or smaller cells such as micro-, femto- or picocells. The (e/g)NodeBs of Fig. 1 may provide any kind of these cells. A cellular radio system may be implemented as a multilayer network including several kinds of cells. Typically, in multilayer networks, one access node provides one kind of a cell or cells, and thus a plurality of (e/g)NodeBs are required to provide such a network structure.

[0057] For fulfilling the need for improving the deployment and performance of communication systems, the concept of “plug-and-play” (e/g)NodeBs has been introduced. Typically, a network which is able to use “plug-and-play” (e/g)Node Bs, includes, in addition to Home (e/g)NodeBs (H(e/g)nodeBs), a home node B gateway, or HNB-GW (not shown in Fig. 1). A HNB Gateway (HNB-GW), which is typically installed within an operator’s network may aggregate traffic from a large number of HNBs back to a core network.

[0058] The Radio Resource Control (RRC) protocol is used in various wireless communication systems for defining the air interface between the UE and a base station, such as eNB/gNB. This protocol is specified by 3GPP in in TS 36.331 for LTE and in TS 38.331 for 5G. In terms of the RRC, the UE may operate in LTE and in 5G in an idle mode or in a connected mode, wherein the radio resources available for the UE are dependent on the mode where the UE at present resides. In 5G, the UE may also operate in inactive mode. In the RRC idle mode, the UE has no connection for communication, but the UE is able to listen to page messages. In the RRC connected mode, the UE may operate in different states, such as CELL DCH (Dedicated Channel), CELL FACH (Forward Access Channel), CELL PCH (Cell Paging Channel) and URA PCH (URA Paging Channel). The UE may communicate with the eNB/gNB via various logical channels like Broadcast Control Channel (BCCH), Paging Control Channel (PCCH), Common Control Channel (CCCH), Dedicated Control Channel (DCCH), Dedicated Traffic Channel (DTCH).

[0059] The transitions between the states is controlled by a state machine of the RRC. When the UE is powered up, it is in a disconnected mode/idle mode. The UE may transit to RRC connected mode with an initial attach or with a connection establishment. If there is no activity from the UE for a short time, eNB/gNB may suspend its session by moving to RRC Inactive and can resume its session by moving to RRC connected mode. The UE can move to the RRC idle mode from the RRC connected mode or from the RRC inactive mode. [0060] The actual user and control data from network to the UEs is transmitted via downlink physical channels, which in 5G include Physical downlink control channel (PDCCH) which carries the necessary downlink control information (DCI), Physical Downlink Shared Channel (PDSCH), which carries the user data and system information for user, and Physical broadcast channel (PBCH), which carries the necessary system information to enable a UE to access the 5G network.

[0061] The user and control data from UE to the network is transmitted via uplink physical channels, which in 5G include Physical Uplink Control Channel (PUCCH), which is used for uplink control information including HARQ feedback acknowledgments, scheduling request, and downlink channel-state information for link adaptation, Physical Uplink Shared Channel (PUSCH), which is used for uplink data transmission, and Physical Random Access Channel (PRACH), which is used by the UE to request connection setup referred to as random access.

[0062] For the 5G technology, one of the most important design goals has been improved metrics of reliability and latency, in addition to network resilience and flexibility. To meet the requirements of emerging applications such as intelligent transportation, augmented virtual reality, industrial automation, etc, three new service categories has been defined for 5G: enhanced mobile broadband (eMBB), massive machine-type communication (mMTC) and ultra-reliable low-latency communication (URLLC).

[0063] The 3 GPP Release 15 and 16 versions of the 5G standard have built the physical implementation of URLLC to meet the two conflicting requirements of reliability and latency. The implementation includes e.g. higher subcarrier spacings and thus shorter OFDM symbol lengths (a.k.a. numerology), sub-slot transmission time intervals, and configured grant resources.

[0064] 3GPP Release 15 introduced a slot-based transmission of OFDM symbols of a packet for PUSCH referred to as repetition Type A, where PUSCH repetition via slot aggregation was supported in a semi-static way, i.e. no repetition within a slot, with aggregation factor of 2, 4 or 8. Therefore, to avoid transmitting a long PUSCH across slot boundary, the UE may transmit (small) PUSCHs in several repetitions scheduled by an uplink grant procedure or RRC in the consecutive available slots. [0065] In the case of paired spectrum (such as in NTN (Non-Terrestrial Network) defined in 3GPP Release 17), the slots for repetitions are determined as consecutive slots:

“For PUSCH repetition Type A, in case K>1,

If the PUSCH is scheduled by DC I format 0 1 or 0 2 if Available SlotCounting is enabled, the same symbol allocation is applied across the NK slots determined for the PUSCH transmission and the PUSCH is limited to a single transmission layer. The UE shall repeat the TB across the NK slots determined for the PUSCH transmission, applying the same symbol allocation in each slot.

Otherwise, the same symbol allocation is applied across the NK consecutive slots and the PUSCH is limited to a single transmission layer. The UE shall repeat the TB across the NK consecutive slots applying the same symbol allocation in each slot.” where N is the number OFDM symbols per slot, K is the number of repetitions, TB is a transport block and downlink control information (DCI) formats define the uplink resource allocation (scheduling grants) for PUSCH.

[0066] Figure 4a shows an example of a PUSCH repetition Type A, where the PUSCH allocation does not span the entire slot.

[0067] PUSCH transmission resources for uplink (UL) may be configured to the UE by the gNB as configured grant (CG) transmission resources. The UE uses these CG resources to transmit data on PUSCH directly to the gNB without transmitting scheduling request (SR) and receiving UL grant as dynamic grant (DG) transmission. For reducing latency, 3GPP Release 16 introduced PUSCH repetition Type B for both DG-based PUSCH and CG-based PUSCH, wherein for a transport block, one dynamic UL grant or one configured grant schedules two or more PUSCH repetitions that can be in one slot, or across slot boundary in consecutive available slots.

[0068] For PUSCH repetition Type B, time domain resource assignment (TDRA) field in downlink control information (DCI) may be used as a basis for deriving the resources for the first repetition. The time domain resources for the remaining repetitions are derived based at least on the resources for the first repetition and UL/DL direction of symbols. The time resource allocation is defined by S (starting symbol), L (length of each repetition) and K (number of repetitions), which are signalled as part of the TDRA entry. TDRA field in DCI indicates one of the entries in the TDRA table. The PUSCH transmission occurs within the time window (AL*K symbols, starting from the indicated starting symbol. [0069] PUSCH repetition Type B are characterized by back-to-back PUSCH repetitions, each repetition of the same length in terms of OFDM symbols. Figure 4b shows an example of a PUSCH repetition Type B for a PUSCH allocation length L=7 OFDM symbols.

[0070] However, before the actual transmission, a UE would consider the downlink symbols as invalid symbols for the PUSCH repetitions as well as symbols indicated as invalid by the higher layer parameter invalidSymbolPattem (invalid meaning that UE cannot transmit in such symbols) as specified in TS 38.214:

“The UE may be configured with the higher layer parameter invalidSymbolPattem, which provides a symbol level bitmap spanning one or two slots (higher layer parameter symbols given by invalidSymbolPattem). A bit value equal to 1 in the symbol level bitmap symbols indicates that the corresponding symbol is an invalid symbol for PUSCH repetition Type B transmission. The UE may be additionally configured with a time-domain pattern (higher layer parameter periodicity AndPattem given by invalidSymbolPattem), where each bit of periodicity AndPattem corresponds to a unit equal to a duration of the symbol level bitmap symbols, and a bit value equal to 1 indicates that the symbol level bitmap symbols is present in the unit. The periodicity AndPattem can be {1, 2, 4, 5, 8, 10, 20 or 40} units long, but maximum of 40 msec. The first symbol of periodicity AndPattem every 40 msec/P periods is a first symbol in frame n/ mod 4 = 0, where P is the duration of periodicityAndPattem-rl6 in units of msec. When periodicityAndPattem is not configured, for a symbol level bitmap spanning two slots, the bits of the first and second slots correspond respectively to even and odd slots of a radio frame, and for a symbol level bitmap spanning one slot, the bits of the slot correspond to every slot of a radio frame.” [0071] This can be clarified by the example scenario of Figure 5, where the groups of l’s and 0’s in the invalidSymbolPattem are pictorially represented by the low rectangles and by the high rectangles, respectively, and the dashed boxes represent each of the 8 scheduled PUSCH repetitions. After applying the pattern to the PUSCH allocation, a UE would not transmit part of the 4^th repetition, as shown from the actual repetitions pattern.

The invalid symbol pattern was originally introduced to avoid UEs transmitting PUSCH in flexible symbols of the frame, where gNB may be configuring different UL or DL transmissions.

[0072] Demodulation Reference Signal (DMRS) bundling is a feature that has been introduced in Rel-17 specifications in the context of the Coverage Enhancements Work Item (WI), aiming at improving channel estimation accuracy by bundling DMRS of PUSCH/PUCCH transmissions across different slots. For UEs in low SNR conditions, channel estimation represents a bottleneck in link performance, and improvements to the channel estimate by bundling DMRSs across multiple slots provides a large benefit in link performance. This feature was introduced for PUSCH or PUCCH repetitions and for a Transport Block over Multiple Slots (TBoMS).

[0073] Thus, the DMRS bundling (or joint channel estimation) feature provides a significant SNR gain and coverage enhancements as long as the bundled DMRS are subject to correlated channel conditions. This would allow for an averaging of the channel estimates across the multiple slots, thereby increasing the reliability of the estimation. However, the feature was developed with the underlying assumption that channel conditions are static throughout the duration of the PUSCH or PUCCH repetitions.

[0074] Nevertheless, in many practical scenarios, channel conditions evolve very rapidly, and application of the coverage enhancements feature DMRS bundling becomes very challenging. Some examples/scenarios where this condition is fulfilled are listed below but other examples are not precluded:

- NTN scenario where the satellites are traveling at high speeds, like LEO (Low-

Earth Orbit) case, and the UE could be also in motion.

- Vehicular communications where both Tx and Rx could be in high mobility.

- Dynamic environment surrounding the transceivers where the scatters/reflectors could be obstructed or moved rapidly.

[0075] In such scenarios, the coherence time of the channel is rather small and, although the frequency offset due to doppler shift can theoretically be pre- or post-compensated, the residual errors could still be large enough to impact the phase continuity of the signal. In addition, recalling that DMRS bundling targets scenarios where the SNR is low, large frequency estimation errors in post- or pre-compensation are to be expected, for example, due to inaccurate ephemeris information, Doppler shifts, Doppler drift and/or Doppler spread.

[0076] In addition, NTN UEs are expected to be able to maintain good time and frequency pre-compensation across multiple slots to cope with the dynamics of an NTN scenario. Thus, PUSCH repetitions Type B, providing all back-to-back repetitions, may not be a desirable option for carrying out the DMRS bundling, since they would not allow a UE to closely follow channel evolution across the multiple slots where repetitions are transmitted in addition to not guaranteeing a good degree of time diversity.

[0077] Figure 6 shows an example of PUSCH repetitions Type A with small number of allocated OFDM symbols combined with DMRS bundling. For such PUSCH or PUCCH transmissions not spanning the entire slot, the channels across different slots could be not correlated enough to provide relevant gains with the DMRS bundling. As a result, a gNB would either have to avoid application of DMRS bundling or be forced to schedule a larger number of OFDM symbols in one slot for the same PUSCH/PUCCH transmission of the same UE to increase the number of available DMRS symbols, which, in turn, may cause a larger system overhead.

[0078] Additionally, considering the large number of UEs that need to be served in an NTN system, the latter possibility would complicate scheduling operations significantly, providing no performance benefit especially for UEs with small number of bits to transmit. Particularly for a PUSCH transmission, an increase in the number of allocated resources for a same code rate would result in an increased transport block size (TBS) that a UE may not have available, rather than in an increased reliability of the transmitted signal. Additionally, 3GPP TR 38.821 has demonstrated that UL link budget is a major issue for NTN links, as for handheld devices with less complex antenna implementations, there is a severe limitation in power in UL, which reduces the amount of resources that may be allocated for the same user at the same time.

[0079] In the following, an enhanced method for PUSCH/PUCCH repetitions will be described in more detail, in accordance with various embodiments.

[0080] The method, which is disclosed in flow chart of Figure 7 as reflecting the operation of a terminal apparatus, such as a user equipment (UE), wherein the method comprises obtaining (700), by a user equipment, a configuration from a network element, the configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmission for said time frame; grouping (702), according to said configuration, the number of transmissions in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets; and using (704), by the user equipment, the grouping of the number of transmissions based on said allocation of symbols for transmitting on said physical uplink channel.

[0081] Thus, the method introduces a new or an enhanced type of allocation of symbols of a transmission block of a physical uplink channel, where a user equipment is configured to transmit subsets of a plurality of repetitions back-to-back in consecutive symbols and slots and provide a gap between consecutive subsets of repetitions. This improves channel estimation accuracy for physical uplink channel transmissions across different slots in scenarios where the coherence time of the channel is small, such as in NTN. The system overhead (in terms of occupied time- frequency resources) remains the same as with PUSCH Type A repetitions while permitting bundling of the DMRSs of the repetitions within the subsets of back-to-back repetitions. In addition, the gap between the subsets of repetitions allows a UE to follow channel evolution as close as possible and timely adjust the time and frequency synchronization of its transmitter to optimize system performance. [0082] According to an embodiment, the grouping of the number of transmissions is either predetermined or based on one or more parameters of said configuration, the parameters including at least one of a number of consecutive transmissions in a subset and a length of the gap between the subsets.

[0083] Thus, the UE may have one or more predefined settings for the grouping of the number of transmissions, and the UE may apply, for example, a default setting or setting signaled by the network. Alternatively, said configuration provided by the network may comprise one or more parameters, such as a number of consecutive transmissions in a subset and/or a length of the gap between the subsets. These parameters may, either explicitly or implicitly, define the grouping of the number of transmissions. [0084] According to an embodiment, determining the gap between subsets of transmissions is based on the allocation of symbols and on the grouping of the number of transmissions.

[0085] Hence, in a case where the length of the gap between the subsets is not explicitly defined, e.g. by a parameter, the UE may determine the gap between subsets of transmissions based on other parameters, such as the allocation of symbols and on the grouping of the number of transmissions.

[0086] Figures 8a and 8b show an example of the enhanced type of repetition, where Figure 8a shows a conventional PUSCH Type A repetition, where the number of repetitions per time frame K=8, and the allocation comprises one repetition per slot. Figure 8b, in turn, shows the enhanced type of repetition, where the number of repetitions to be grouped as subsets of repetitions is 3. Starting from the first repetition in the first slot, two subsequent repetitions are bundled with it to form a first subset of three repetitions. The second subset of three repetitions comprises the 4^th, 5^th and 6^th repetitions, starting from the position of the 4^th repetition. As a result, a gap larger than one slot is created between the first and the second subset of repetitions, providing the UE with more time to follow the channel evolution and carry out adjustments, if needed. Since the number of repetitions per time frame is 8, the third subset of repetitions comprises only two repetitions, nevertheless providing a gap larger than one slot between the second and the third subset of repetitions. [0087] According to an embodiment, the number of transmission to be grouped as subsets is two, and the allocation of the symbols in every other slot, starting from the first slot, comprises a number of symbols in an end of the slot and the allocation of the symbols in alternating slots, starting from the second slot, comprises a number of symbols in a beginning of the slot.

[0088] Thus, when the number of repetitions to be grouped as subsets of repetitions is two, this embodiment provides pairs of repetitions configured back-to-back in consecutive slots. Such straightforward configuration still allows to double the number of DMRSs that the gNB could use for joint channel estimation.

[0089] Figure 9 shows an example of the enhanced type of repetition, where each pair of repetitions is transmitted back-to-back and potentially within the coherence time of the channel, allowing for bundling of the respective DMRSs to improve the channel estimation accuracy. It is noted that the DMRS density and allocation for the single repetition does not require any changes and therefore remains unchanged.

[0090] For illustrative and simplification purposes, some embodiments are described herein as using two repetitions to be grouped as subsets of repetitions. It is, however, noted that also these embodiments can be applied in more generalized cases, where the number of repetitions to be grouped as subsets of repetitions is more than two.

[00 1] According to an embodiment, the allocation of the symbols of the transmission block is applied for Physical Uplink Shared Channel (PUSCH) repetitions or Physical Uplink Control Channel (PUCCH) repetitions.

[0092] Thus, the enhanced type of repetition is applicable as a new type of PUSCH repetition, wherein compared to PUSCH repetitions Type A, the now introduced new type of repetition allows for increasing the number of DMRSs that a gNB may use for joint channel estimation without sacrificing additional network resources, even in the cases of small coherence time of the channel. It is noted that the residual frequency offset in an NTN-system may be above 1 kHz, generating a channel coherence time smaller than one slot.

[0093] Compared to PUSCH repetitions Type B, the now introduced new type of repetition provides the repetitions as back-to-back only in subsets, instead of providing all repetitions consecutively, thereby allowing a UE to constantly follow the evolution of the physical channel and to keep its transmitter synchronized to optimize system performance, in the gap period between the subsets. In an NTN-like scenario, it is of utmost importance for a UE to constantly adjust its time and frequency synchronization to follow channel evolution as close as possible. In addition, the new scheme would allow a lower degree of resource occupancy (on a slot-by-slot basis) and larger time diversity compared to a PUSCH repetition Type B scheme

[0094] Moreover, the now introduced new type of repetition is also applicable to PUCCH repetition, for which a Type-B like repetition scheme is not currently supported. It is noted that within the features of 3 GPP Release 17 DMRS bundling is the only feature providing SNR gains for the PUCCH channel in case of low SNR conditions. Thus, having the possibility of applying the feature DMRS bundling to a PUCCH transmission also in an NTN scenario by applying the now introduced new type of repetition is of great importance.

[0095] According to an embodiment, the method comprises obtaining, by the user equipment, from the network element, a first indication with an allocation of the symbols across the plurality of slots for the transmission of a Physical Uplink Shared Channel (PUSCH) Type A repetition; and obtaining, within the configuration from the network element, a second indication to change the allocation of the symbols, wherein according to said configuration, a number of PUSCH repetitions are grouped in a first subset and a number of PUSCH repetitions are grouped in a second subset, wherein a first PUSCH repetition of the first and second subset is in the same slot and symbols, in time-wise order, as the corresponding PUSCH repetition is in the PUSCH Type A repetition.

[0096] Thus, in one example, in the beginning the gNB may configure the UE to use the conventional PUSCH Type A repetition. When considered necessary, the gNB may provide the UE with a second indication, thereby configuring the UE to use the now introduced new type of repetition. The second indication, which is herein referred to by an exemplifying term swap allocation flag (any other term may also be used), may be defined as an enhancement to the conventional PUSCH Type A repetition, for example as follows in case of N-K repetitions in paired spectrum: if the PUSCH is scheduled by DCI format 0 1 or 0 2, and swap allocation flag in the DCI is set to 1, the symbol allocation in even slots among the N-K slots is the same as indicated by the scheduling DCI, and the symbol allocation in odd slots among the N-K slots is derived as Ngy^_b — n — 1, where n are the indexes of the symbols allocated by DCI, and the PUSCH is limited to a single transmission layer. The slot indicated for the first PUSCH transmission has number 0. The UE shall repeat the TB across the N-K consecutive slots applying the same symbol allocation in each slot.

[0097] Accordingly, for implementation of the now introduced new type of repetition, the UE just needs to swap the time allocation provided in the scheduling DCI in the odd slots where UE transmits the k^th repetition, for k = 1, 3, ... , numberOfRepetitions, where the slot for the 1^st repetition is slot number 0. The swapping can be realized by computing the indexes of the OFDM symbols for transmission in the odd slots as N^y^_b — n — 1, where N^y^_b = 14 for normal cyclic prefix and n are the indexes of the OFDM symbols allocated by DCI and used for transmission in the even slots. The slot where the first PUSCH transmission occurs is slot number 0 for this counting. This further ensures that each subset starts in a position corresponding to a position of a transmission in the PUSCH Type A repetition. For example, if the number of transmissions in a subset is two, the second subset starts in the same slot and symbol, in time- wise order, as the third transmission in the PUSCH Type A repetition.

[0098] According to an embodiment, the transmission on the physical uplink channel comprises demodulation reference signals (DMRS) for demodulation of the physical uplink channel at a receiver.

[0099] According to an embodiment, the method comprises providing the network element with measurement data relating to channel conditions.

[0100] Hence, the UE may monitor the experienced Doppler spread and/or more directly the expected performance of the frequency shift pre- compensation on the currently experienced channel. The UE may then periodically report e.g. the experienced Doppler spread to the gNB, either implicitly or explicitly. Implicitly refers to the UE being scheduled to transmit a reference signal for Doppler spread estimation to the gNB.

Explicitly refers to the UE reporting the actual Doppler spread, for example in UCI (Uplink Control Information) or a MAC control element (MAC CE).

[0101] The gNB may then conclude, based on the reports from the UE, that the channel conditions are too non-static throughout the duration of the PUSCH repetitions. The gNB may then configure the UE to use the enhanced type of repetition, for example, by sending the second indication to the UE. As a result, the UE transmits pairs of two repetitions back- to-back in consecutive slots, thereby enabling bundling of the DMRSs of each two consecutive back-to-back repetitions, as shown in Figure 8.

[0102] The method and at least some of the embodiments is illustrated in the signalling chart of Figure 10. The method starts by the network, such as the gNB, sending a first indication (1000) to the UE to use a Physical Uplink Shared Channel (PUSCH) Type A repetition as the allocation of the symbols of the transmission block across the plurality of consecutive slots. The first indication configures the UE, either implicitly interpreted by the UE or explicitly indicated e.g. by a flag, for operation with Enhanced Type A repetitions, such that when indicated by the network, such as the gNB, the UE shifts to transmit the PUSCH/PUCCH repetitions with swapped allocation in odd slots. Next, the UE periodically reports e.g. the experienced Doppler spread (1002) to the gNB. Based on this, the gNB schedules the UE with two PUSCH (or PUCCH) repetitions (1004), as well as sets the flag swap allocation in the scheduling DCI to 1 (1006). The UE then transmits the PUSCH or PUCCH with enhanced Type A repetitions, wherein the first repetition is transmitted on the indicated OFDM symbols (1008) and the second repetition is transmitted on swapped OFDM symbols (1010).

[0103] According to an embodiment, the method comprises changing an order of the symbols in every other slot, starting from the second slot, to be opposite to their original time-wise order.

[0104] Thus, the allocation swap may be applicable to the transmission of all OFDM symbols of the slot. That is, the slot is time- wise mirrored such that any symbol that would normally be placed in symbol number 14 would be transmitted in symbol number 1 and vice versa, symbol number 13 would be transmitted in symbol number 2 and vice versa, etc. (including new positions for the DMRS, which are a part of the swapping). Such scheme would allow the gNB to make a linear interpolation of the channel estimate between the two end points between the two back-to-back repetitions (as the normal front- loaded DMRS would be occurring at the end of the UL transmission on the swapped transmission). According to the embodiment, new DMRS positions are defined when the allocation in odd slots is swapped. Figure 11 shows an exemplified representation of the embodiment where, compared to the embodiment shown in Figure 8, the entire second slot has been mirrored, including the DMRS positions.

[0105] As described above, the network may signal to the UE the number of repetitions to be transmitted, and the number of repetitions in a subset. For example, in Figure 9, there are 4 repetitions, and the DMRS subset size is equal to 2, such that only 2 contiguous repetitions are transmitted back-to-back. In other applications, depending on how fast is the doppler spread varying, there may be other configurations, for example: a DMRS subset size equal to 4, and a total number of repetitions equal to 16, where the subset of 4 repetitions is transmitted all back-to-back.

[0106] An apparatus, such as a UE, according to an aspect comprises means for means for obtaining a configuration from a network element, the configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; means for grouping, according to said configuration, the number of transmissions in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets; and means for using the grouping of the number of transmissions based on said allocation of symbols for transmitting on said physical uplink channel.

[0107] According to an embodiment, the physical uplink channel is Physical Uplink Shared Channel (PUSCH) or Physical Uplink Control Channel (PUCCH).

[0108] According to an embodiment, the grouping of the number of transmissions is either predetermined or based on one or more parameters of said configuration, the parameters including at least one of a number of consecutive transmissions in a subset and a length of the gap between the subsets.

[0109] According to an embodiment, the apparatus comprises means for determining the gap between subsets of transmissions based on the allocation of symbols and on the grouping of the number of transmissions.

[0110] According to an embodiment, the number of transmissions to be grouped as subsets is two, and the allocation of the symbols in every other slot, starting from a first slot, comprises a number of symbols in an end of the slot and the allocation of the symbols in alternating slots, starting from a second slot, comprises a number of symbols in a beginning of the slot.

[0111] According to an embodiment, the transmission on the physical uplink channel comprises demodulation reference signals (DMRS) for demodulation of the physical uplink channel at a receiver.

[0112] According to an embodiment, the apparatus comprises means for obtaining, from the network element, a first indication with an allocation of the symbols across the plurality of slots for the transmission of a Physical Uplink Shared Channel (PUSCH) Type A repetition; and means for obtaining, within the configuration from the network element, a second indication to change the allocation of symbols, according to which said means for grouping the number of transmissions is configured to group, according to said configuration, a number of PUSCH repetitions in a first subset and a number of PUSCH repetitions in a second subset, wherein a first PUSCH repetition of the first and second subset is in the same slot and symbols, in time- wise order, as the corresponding PUSCH repetition in the PUSCH Type A repetition.

[0113] According to an embodiment, the apparatus comprising means for changing an order of the symbols in every other slot, starting from the second slot, to be opposite to their original time-wise order.

[0114] According to an embodiment, the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0115] An apparatus according to a further aspect comprises at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: obtain a configuration from a network element, the configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; group, according to said configuration, the number of transmissions in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets; and use the grouping of the number of transmissions based on said allocation of symbols for transmitting on said physical uplink channel.

[0116] Such apparatuses may comprise e.g. the functional units disclosed in any of the Figures 1, 2 and 3 for implementing the embodiments.

[0117] A further aspect relates to a computer program product, stored on a non- transitory memory medium, comprising computer program code, which when executed by at least one processor, causes an apparatus at least to perform: obtain a configuration from a network element, the configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; group, according to said configuration, the number of transmissions in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets; and use the grouping of the number of transmissions based on said allocation of symbols for transmitting on said physical uplink channel.

[0118] Another aspect relates to the operation of a base station or an access point, such as a gNB, for configuring a user equipment to applying the now introduced new type of repetition.

[0119] The flow chart of Figure 12 illustrates a method carried out by a base station, wherein the method comprises providing (1200), by a network element, a user equipment with a configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; and receiving (1202), from the user equipment, transmissions on said physical uplink channel, wherein the number of transmissions are grouped in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets.

[0120] Accordingly, the base station or the access point, such as a gNB, provides the UE with a configuration or an indication to use the new type of repetition across a plurality of slots of a time frame. The UE applies the new type of repetition for its transmissions on physical uplink channel, and the gNB receives the transmissions, where the number of transmissions are grouped in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets.

[0121] The method and the embodiments related thereto may be implemented in an apparatus implementing an access point or a base station of a radio access network, such as an eNB or a gNB. The apparatus may comprise at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: provide a user equipment with a configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; and receive, from the user equipment, transmissions on said physical uplink channel, wherein the number of transmissions are grouped in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets.

[0122] Such an apparatus may likewise comprise: means for providing a user equipment with a configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; and means for receiving, from the user equipment, transmissions on said physical uplink channel, wherein the number of transmissions are grouped in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets.

[0123] In general, the various embodiments of the invention may be implemented in hardware or special purpose circuits or any combination thereof. While various aspects of the invention may be illustrated and described as block diagrams or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods 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.

[0124] Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0125] Programs, such as those provided by Synopsys, Inc. of Mountain View, California and Cadence Design, of San Jose, California automatically route conductors and locate components on a semiconductor chip using well established rules of design as well as libraries of pre stored design modules. Once the design for a semiconductor circuit has been completed, the resultant design, in a standardized electronic format (e.g., Opus, GDSII, or the like) may be transmitted to a semiconductor fabrication facility or "fab" for fabrication.

[0126] The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended examples. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention.

Claims

1. An apparatus comprising: means for obtaining a configuration from a network element, the configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; means for grouping, according to said configuration, the number of transmissions in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets; and means for using the grouping of the number of transmissions based on said allocation of symbols for transmitting on said physical uplink channel.

2. The apparatus according to claim 1, wherein the physical uplink channel is Physical Uplink Shared Channel (PUSCH) or Physical Uplink Control Channel (PUCCH).

3. The apparatus according to claim 1 or 2, wherein the grouping of the number of transmissions is either predetermined or based on one or more parameters of said configuration, the parameters including at least one of a number of consecutive transmissions in a subset and a length of the gap between the subsets.

4. The apparatus according to claim 3, comprising means for determining the gap between subsets of transmissions based on the allocation of symbols and on the grouping of the number of transmissions.

5. The apparatus according to any preceding claim, wherein the number of transmissions to be grouped as subsets is two, and the allocation of the symbols in every other slot, starting from a first slot, comprises a number of symbols in an end of the slot and the allocation of the symbols in alternating slots, starting from a second slot, comprises a number of symbols in a beginning of the slot.

6. The apparatus according to any preceding claim, wherein the transmission on the physical uplink channel comprises demodulation reference signals (DMRS) for demodulation of the physical uplink channel at a receiver.

7. The apparatus according to any preceding claim, comprising means for obtaining, from the network element, a first indication with an allocation of the symbols across the plurality of slots for the transmission of a Physical Uplink Shared Channel (PUSCH) Type A repetition; and means for obtaining, within the configuration from the network element, a second indication to change the allocation of symbols, according to which said means for grouping the number of transmissions is configured to group, according to said configuration, a number of PUSCH repetitions in a first subset and a number of PUSCH repetitions in a second subset, wherein a first PUSCH repetition of the first and second subset is in the same slot and symbols, in time- wise order, as the corresponding PUSCH repetition in the PUSCH Type A repetition.

8. The apparatus according to any preceding claim, comprising means for changing an order of the symbols in every other slot, starting from the second slot, to be opposite to their original time-wise order.

9. A method comprising: obtaining, by a user equipment, a configuration from a network element, the configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; grouping, according to said configuration, the number of transmissions in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets; and using, by the user equipment, the grouping of the number of transmissions based on said allocation of symbols for transmitting on said physical uplink channel.

10. The method according to claim 9, wherein the physical uplink channel is Physical Uplink Shared Channel (PUSCH) or Physical Uplink Control Channel (PUCCH).

11. The method according to claim 9 or 10, wherein the grouping of the number of transmissions is either predetermined or based on one or more parameters of said configuration, the parameters including at least one of a number of consecutive transmissions in a subset and a length of the gap between the subsets.

12. The method according to claim 11, comprising determining the gap between subsets of transmissions based on the allocation of symbols and on the grouping of the number of transmissions.

13. The method according to any of claims 9 - 12, wherein the number of transmissions to be grouped as subsets of repetitions is two, and the allocation of the symbols in every other slot, starting from a first slot, comprises a number of symbols in an end of the slot and the allocation of the symbols in alternating slots, starting from a second slot, comprises a number of symbols in a beginning of the slot.

14. An apparatus comprising: means for providing a user equipment with a configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; and means for receiving, from the user equipment, transmissions on said physical uplink channel, wherein the number of transmissions are grouped in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets.

15. A method comprising: providing, by a network element, a user equipment with a configuration comprising an allocation of symbols for a transmission on a physical uplink channel across a plurality of slots of a time frame, wherein the allocation of the symbols is configured to be used for a number of transmissions for said time frame; and receiving, from the user equipment, transmissions on said physical uplink channel, wherein the number of transmissions are grouped in two or more subsets, each subset comprising two or more consecutive transmissions, wherein a gap is determined between said subsets.