Transmitting device, receiving device, transmitting method, receiving method, and integrated circuit

Abstract

To facilitate providing flexible reference signal settings for demodulation during data channel repetition.SOLUTION: A transmitting device according to one embodiment of the present disclosure includes a circuit that, in operation, allocates data to a plurality of TTIs including an initial transmission time interval (TTI) and one or more subsequent TTIs following the initial TTI, assigns a demodulation reference signal (DMRS) to the initial TTI, and obtains DMRS allocation indicating whether a DMRS is allocated to each subsequent TTI of the one or more subsequent TTIs, and in which multiple TTIs are each represented by consecutive symbols within a slot, and a transceiver that, in operation, transmits data and the DMRS to a receiving device within a slot, and in which transmission of the DMRS in one or more subsequent TTIs is performed according to the DMRS assignment, and symbols between the multiple TTIs are assigned symbols that are not valid for uplink transmission.SELECTED DRAWING: Figure 16

Description

[Technical field]

[0001] The present disclosure relates to transmission and reception, devices and methods in communication systems, such as 3GPP (3rd Generation Partnership Project) communication systems. [Background technology]

[0002] Recently, the 3rd Generation Partnership Project (3GPP) completed the first release (Release 15) of technical specifications for the next generation cellular technology, also referred to as the fifth generation (5G). At 3GPP's Technical Specification Group (TSG) Radio Access network (RAN) Meeting #71 (March 2016, Gothenburg), the first study item for 5G, "Study on New Radio Access Technology", involving RAN1, RAN2, RAN3, and RAN4, was approved as a possible work item for Release 15 that will define the first standard for 5G. The objective of the study item is to develop “New Radio” (NR) access technologies defined during the RAN requirements study that will operate in frequency bands up to 100 GHz and support a wide range of use cases (see, for example, 3GPP TR 38.913, “Study on Scenarios and Requirements for Next Generation Access Technologies”, current version 14.3.0, available at www.3gpp.org).

[0003] The International Mobile Telecommunications-2020 (IMT-1010) specification by the International Telecommunications Union broadly categorized three major scenarios for next-generation mobile communications: enhanced Mobile Broadband (eMBB), massive Machine-type Communications (mMTC), and Ultra-Reliable and Low-Latency Communications (URLLC). In the recently completed 3GPP Release 15, the main focus was to standardize the specifications for eMBB and the initial support for URLLC. For example, deployment scenarios for eMBB may include indoor hotspots, dense urban areas, suburban, urban, and high-speed. Deployment scenarios for URLLC may include industrial control systems, mobile health management (remote monitoring, diagnosis, and treatment), real-time control of vehicles, and wide-area monitoring and control systems for smart grids. mMTC may include scenarios using a large number of devices with low latency sensitive data transmission, such as smart wearables and sensor networks.

[0004] In Release 15, the scope of URLLC for reliability includes the specification of new CQI (Channel Quality Indicator) and MCS (Modulation and Coding Scheme) table design for target BLER of 1E-5 in addition to the already agreed tables for target BLER of 1E-1. For URLLC, one new RRC parameter is introduced to configure a new RNTI (Radio Network Temporary Identifier) ​​for grant-based transmission. If a new RNTI is not configured, the existing RRC parameter "mcs-table" is extended to select between three MCS tables (existing 64QAM MCS table, existing 256QAM MCS table, new 64QAM MCS table). If mcs-table indicates the new 64QAM MCS table, for DCI formats 0_0 / 1_0 in CSS (Common Search Space) the existing 64QAM MCS table is used and for DCI formats 0_0 / 1_0 / 0_1 / 1_1 in USS (User Search Space) the new 64QAM MCS table is used. Otherwise, the existing behavior is followed. If a new RNTI is configured (via RRC (Radio Resource Control)), the RNTI scrambling of the DCI CRC is used to select the MCS table. If the DCI CRC is scrambled with the new RNTI, the new 64QAM MCS table is used. Otherwise, follow existing behavior. The above configurations for DL ​​(Downlink) and UL (Uplink) are separate.

[0005] The scope of URLLC reliability in Rel. 15 was quite limited. Therefore, a new study item on physical layer enhancements for NR URLLC was approved in RAN#80 (see RP-181477 "New SID on Physical Layer Enhancements for NR URLLC", Huawei, HiSilicon, Nokia, Nokia Shanghai Bell). In Rel. 15, basic support for URLLC was introduced. For NR URLLC Rel. 16, further use cases with more stringent requirements have been identified, such as factory automation, transportation industry, and power distribution. Summary of the Invention

[0006] One non-limiting illustrative embodiment facilitates providing flexible demodulation reference signal configuration during repetition of a Data Channel.

[0007] In one general aspect, the disclosed technology features a transmitting device for transmitting data to a receiving device in a communication system. The transmitting device includes a circuit for, during operation, allocating data to a plurality of transmission time intervals (TTIs) including an initial TTI and one or more subsequent TTIs following the initial TTI, allocating a demodulation reference signal (DMRS) to the initial TTI, and obtaining, for each of the one or more subsequent TTIs, a DMRS allocation indicating whether a DMRS is allocated to the subsequent TTI for transmission in addition to data. Each of the plurality of TTIs includes a number of symbols less than a slot, and the data allocated to each TTI of the plurality of TTIs is identical. The transmitting device further includes a transceiver for, during operation, transmitting, within a slot, the data and the DMRS allocated to the initial TTI and the data allocated to the one or more subsequent TTIs to the receiving device. The DMRS transmission in the one or more subsequent TTIs is performed in accordance with the DMRS allocation.

[0008] It should be noted that the general or specific embodiments may be realized as a system, a method, an integrated circuit, a computer program, a storage medium, or any combination thereof.

[0009] Further benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. These benefits and / or advantages may be obtained individually by various embodiments and features of the specification and drawings. However, it is not necessary for all of these features to be present in order to obtain one or more of such benefits and / or advantages. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an example architecture for a 3GPP NR system. [Diagram 2] FIG. 1 is a block diagram of an example user and control plane architecture for an LTE eNB, an NR gNB, and a UE. [Diagram 3] Schematic diagram showing usage scenarios for Massive Machine-Type Communication (mMTC) and Ultra-Reliable Low Latency Communication (URLLC). [Figure 4] 1 is a diagram of an example of inter-slot repetition of a two-symbol PUSCH (Physical Uplink Shared Channel). [Diagram 5] FIG. 13 is a diagram of an example of repetition of a 4-symbol PUSCH in the same slot. [Figure 6] 1 illustrates an example of an 8-symbol PUSCH with one additional DMRS (Demodulation Reference Signal). [Figure 7] 1 illustrates repetition with frequency hopping. [Figure 8] 1 shows repetition with beam hopping. [Figure 9] FIG. 13 illustrates an example of repetition on measurement resources in a configured grant. [Figure 10] FIG. 2 illustrates an example of a two-symbol PUSCH transmission with six repetitions in one slot. [Figure 11]1 is a block diagram of a transmitting device and a receiving device. [Figure 12] 1 is a block diagram of a circuit of a transmitting device. [Figure 13] 4 is a flowchart of a transmission method and a reception method. [Figure 14] 1 illustrates an example of removal of DMRS symbols from a particular repetition within a slot. [Figure 15] 4 illustrates an example of permutation of DMRS symbols with data symbols in a particular repetition within a slot. [Figure 16] 1 illustrates an example of combined removal and replacement of DMRS symbols in a slot. [Figure 17] 4 is a flowchart of an uplink transmission method and an uplink reception method. [Figure 18] 13 is a graph illustrating example control signaling for DMRS allocation. [Figure 19] FIG. 1 illustrates an example of repetition with frequency hopping. [Figure 20] FIG. 13 is a diagram showing an example of repetition involving beam hopping. [Figure 21] FIG. 13 illustrates an example of repetition on measurement resources in a configured grant. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] As presented in the Background section, 3GPP is working on the next release of the fifth generation of cellular technology, simply referred to as 5G, including the development of New Radio (NR) access technology that will operate at frequencies in the range up to 100 GHz. 3GPP must identify and develop the technology components required to successfully standardize an NR system that meets both immediate market needs and longer-term requirements in a timely manner. To achieve this, the evolution of the air interface and radio network architecture is being considered in the study item "New Radio Access Technology." Results and consensus have been collected in technical report TR 38.804 v14.0.0, which is incorporated herein by reference in its entirety.

[0012] Among other things, there is a tentative agreement on the overall system architecture. The NG-RAN (Next Generation-Radio Access Network) includes the gNB, which provides the NG-Radio Access User Plane, SDAP / PDCP / RLC / MAC / PHY (Service Data Adaptation Protocol / Packet Data Convergence Protocol / Radio Link Control / Medium Access Control / Physical) and control plane, RRC (Radio Resource Control) protocol termination towards the UE. The NG-RAN architecture is shown in FIG. 1 based on TS 38.300 v.15.0.0, section 4, which is incorporated herein by reference. The gNBs are interconnected with each other by the Xn interface. The gNBs are also connected to the NGC (Next Generation Core) by the Next Generation (NG) interface, more specifically to the AMF (Access and Mobility Management Function) (e.g., a specific core entity that runs the AMF) by the NG-C interface and to the UPF (User Plane Function) (e.g., a specific core entity that runs the UPF) by the NG-U interface.

[0013] For example, as reflected in 3GPP TR 38.801 v14.0.0 "Study on new radio access technology: Radio access architecture and interfaces", various different deployment scenarios are currently being discussed to be supported. For example, a decentralized deployment scenario (Section 5.2 of TR 38.801; a centralized deployment is shown in Section 5.4; which is incorporated herein by reference) is presented therein, in which base stations supporting 5G NR can be deployed. Figure 2 illustrates an exemplary decentralized deployment scenario, based on Figure 5.2.-1 of TR 38.801, above, but additionally showing an LTE eNB and user equipment (UE) connected to both a gNB and an LTE eNB. As previously mentioned, the new eNB for NR 5G may be exemplarily referred to as a gNB.

[0014] Also, as mentioned above, the 3rd Generation Partnership Project New Radio (3GPP NR) considers three use cases that are envisioned to support a wide variety of services and applications with IMT-2020 (see Recommendation ITU-R M.2083: IMT vision - "Framework and overall objectives of the future development of IMT for 2020 and beyond", September 2015). Specifications for Phase 1 of Enhanced Mobile Broadband (eMBB) were finalized by 3GPP in December 2017. In addition to further extending eMBB support, current and future work will involve standardization of Ultra-Reliable and Low-Latency Communications (URLLC) and Large Scale Machine Type Communications. Figure 3 (from Recommendation ITU-R M.2083) shows some examples of envisioned usage scenarios for IMT beyond 2020.

[0015] URLLC use cases have stringent requirements for capabilities such as throughput, latency, and availability, and are envisioned as one of the enablers for future vertical applications such as wireless control of industrial manufacturing or production processes, remote surgery, power distribution automation in smart grids, transportation safety, etc. In the current WID (Work Item Description) RP-172115, it is agreed to support ultra-high reliability for URLLC by identifying technologies that meet the requirements set by TR 38.913.

[0016] For NR URLLC in Release 15, key requirements include a target user plane delay of 0.5 ms for UL (uplink) and 0.5 ms for DL ​​(downlink). A typical URLLC requirement for one transmission of a packet is a BLER (block error rate) of 1E-5 for a packet size of 32 bytes with a user plane of 1 ms. From a RAN1 perspective, reliability can be improved in several possible ways. The current scope for improving reliability is captured in RP-172817, including the definition of separate CQI tables for URLLC, more compact DCI formats, PDCCH repetition, etc. However, as NR becomes more stable and developed, the scope may be broadened to achieve ultra-high reliability (for key requirements of NR URLLC, see also 3GPP TR 38.913 V15.0.0 "Study on Scenarios and Requirements for Next Generation Access Technologies", which is incorporated herein by reference). Therefore, NR URLLC in Release 15 must be able to transmit 32-byte data packets within a user plane delay of 1 ms with a success rate corresponding to a BLER of 1E-5. Specific use cases for NR URLLC in Rel. 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications (see also ITU-R M.2083-0).

[0017] Furthermore, technology enhancements targeted by NR URLLC in Release 15 aim at delay improvement and reliability improvement. Technology enhancements for delay improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition for data channels, and downlink preemption. Preemption means that a transmission for which resources have already been allocated is stopped and the already allocated resources are used for another transmission that is requested later but has lower delay / higher priority requirements. Thus, a transmission that is already allowed is preempted by a later transmission. Preemption is applicable independent of the particular service type. For example, a transmission for service type A (URLLC) can be preempted by a transmission for service type B (eMBB, etc.). Technical enhancements for improved reliability include dedicated CQI / MCS tables for a target BLER of 1E-5 (for such enhancements, see also 3GPP TS 38.211 "NR; Physical channels and modulation", TS 38.212 "NR; Multiplexing and channel coding", TS 38.213 "NR; Physical layer procedures for control", and TS 38.214 "NR; Physical layer procedures for data", each version V15.2.0, all of which are incorporated herein by reference).

[0018] The mMTC use case is characterized by a very large number of connected devices that typically transmit a relatively small amount of non-latency sensitive data. The devices are required to be cheap and have a very long battery life. From an NR perspective, utilizing very narrow bandwidth portions is one possible solution to be power-saving from the UE perspective and enable a long battery life.

[0019] As mentioned above, it is expected that the scope of reliability in NR will be broader. One key requirement for all cases, especially for URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can be considered to improve reliability from a radio perspective and a network perspective. There are a few key areas that could potentially help to improve reliability. Among these areas are compact control channel information, data / control channel repetition, and diversity on frequency, time, and / or spatial domains. These areas are generally applicable to reliability, regardless of the specific communication scenario.

[0020] For NR URLLC Rel.16, additional use cases with more stringent requirements have been identified, such as factory automation, transportation industry, and power distribution (see RP-181477, “New SID on Physical Layer Enhancements for NR URLLC,” Huawei, HiSilicon, Nokia, Nokia Shanghai Bell, incorporated herein by reference). These more stringent requirements are driven by higher reliability (up to 10x the bandwidth required) depending on the use case. -6 level), higher availability, packet size up to 256 bytes, time synchronization down to the order of a few μs (the value can be 1 μs or a few μs depending on the frequency range), and low latency on the order of 0.5-1 ms (in particular a target user plane latency of 0.5 ms) (see also 3GPP TS 22.261 “Service requirements for next generation new services and markets” V16.4.0 and RP-181477, which are incorporated herein by reference).

[0021] Furthermore, for NR URLLC in Rel.16, several technology enhancements from a RAN1 perspective are specified. Among these are PDCCH enhancements related to compact DCI, PDCCH (Physical Downlink Control Channel) repetition, and increased PDCCH monitoring. Furthermore, UCI (Uplink Control Information) enhancements are related to enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback enhancements. Also, PUSCH enhancements and retransmission / repetition enhancements related to minislot level hopping are specified. The term "minislot" refers to a transmission time interval (TTI) that contains fewer symbols than a slot (a slot containing 14 symbols).

[0022] In general, the TTI defines the timing granularity for scheduling assignments. One TTI is the time interval in which a given signal is mapped to the physical layer. Conventionally, the TTI length can vary from 14 symbols (slot-based scheduling) to 2 symbols (non-slot-based scheduling). Downlink and uplink transmissions are specified to be organized into frames (10 ms duration) consisting of 10 subframes (1 ms duration). In slot-based transmissions, the subframes are divided into slots. The number of slots is defined by the numerology / subcarrier spacing, and the specified values ​​range between 10 slots for a subcarrier spacing of 15 kHz and 320 slots for a subcarrier spacing of 240 kHz. The number of OFDM symbols per slot is 14 for normal cyclic prefix and 12 for extended cyclic prefix (see sections 4.1 (general frame structure), 4.2 (Numerologies), 4.3.1 (frames and subframes), and 4.3.2 (slots) of 3GPP TS 38.211 V15.0.0(2017-12), which is incorporated herein by reference). However, the allocation of time resources for transmissions may be non-slot based. In particular, a TTI in a non-slot based allocation may correspond to a mini-slot instead of a slot. That is, one or more mini-slots may be allocated to a requested transmission of data / control signaling. In a non-slot based allocation, the minimum length of a TTI may conventionally be 2 OFDM symbols.

[0023] Other specified enhancements relate to scheduling / HARQ / CSI processing timelines and UL inter-UE Tx prioritization / multiplexing. Exemplary methods such as UL configured grant (grant-free) transmissions focusing on improved configured grant behavior, explicit HARQ-ACK, guaranteeing K repetitions and minislot repetition within a slot, and other MIMO (multiple-input multiple-output) related enhancements are further specified (see also 3GPP TS 22.261 V16.4.0).

[0024] This disclosure relates to potential Layer 1 enhancements to further improve reliability / latency and for other requirements related to use cases identified in (RP-181477 "New SID on Physical Layer Enhancements for NR URLLC", Huawei, HiSilicon, Nokia, Nokia Shanghai Bell). In particular, enhancements for PUSCH (Physical Uplink Shared Channel) repetition are discussed. The impact of the proposed ideas in this disclosure is expected to be on PUSCH repetition extensions, which are within the main scope of the new SI (Study Item) / WI (Work Item) for NR URLLC in Rel.16.

[0025] (PUSCH repeat) One of the scopes for potential extensions relates to minislot repetition of PUSCH within a slot. In the following, motivation is provided for supporting PUSCH repetition within a slot, which may enable potential extensions to the repetition mechanism to further improve reliability and / or latency to meet new requirements of NR URLLC.

[0026] To achieve the delay requirement for URLLC PUSCH transmission, one-shot transmission (i.e., single (TTI) allocation) is ideal if the reliability requirement is met. However, the target BLER of 1E-5 is not always achieved with one-shot transmission. Therefore, a retransmission or repetition mechanism is required. In NR Rel. 15, both retransmission and repetition are supported to achieve the target BLER when one-shot transmission is not sufficient. It is well known that HARQ-based retransmission improves the overall reliability by using feedback information and improving subsequent retransmissions depending on the channel condition. However, retransmission incurs additional delay due to the feedback processing timeline. Therefore, repetition is useful for delay-tolerant services, since subsequent transmissions of the same data packet are made without waiting for feedback.

[0027] PUSCH repetition can be defined as "transmitting the same uplink data packet multiple times without waiting for feedback of one or more previous transmissions of the same data packet." The advantage of PUSCH repetition is that it improves overall reliability and reduces delay compared to HARQ, since no feedback is required. However, in general, link adaptation is not possible and resource usage may be inefficient.

[0028] In NR Rel.15, limited support for repetition is introduced. Only semi-static configuration of repetition is allowed. Furthermore, repetition is only allowed between slots (slot-level PUSCH repetition) as shown in Figure 4. That is, repetition is only possible in the slot following the slot of the previous transmission. Depending on the numerology and service type (e.g., URLLC, eMBB), the delay between repetitions may be too long for inter-slot repetition. Such type of repetition is mainly useful for PUSCH mapping type A, which allows PUSCH transmissions to start only from the beginning of a slot. Such limited support may not be able to achieve the stricter delay requirement in NR Rel.15, i.e., a maximum delay of 0.5 ms. Therefore, PUSCH repetition within a slot is considered for NR URLLC in Rel.16.

[0029] Repetitions within the same slot may be supported for PUSCH mapping type B, which allows scheduling of a given transmission (or repetitions from any symbol in the slot, as opposed to only the beginning of the slot in PUSCH mapping type A). For example, two repetitions may be scheduled adjacently within a slot, as shown in Figure 5. This results in even lower delay between repetitions compared to inter-slot repetitions. In this figure, a single transmission consists of one DMRS symbol and three data symbols, followed by the exact same repetition.

[0030] However, it can be shown that the exact same configuration can be achieved with a single transmission without repetition. Essentially, the length of the initial transmission is longer and an additional DMRS symbol is configured. This is supported in NR Rel.15, where the additional DMRS is assigned to the 5th symbol of the slot, as shown in Figure 6. In the example shown in Figure 6, the single transmission consists of one front-end DMRS + one additional DMRS configuration and 6 data symbols, which is essentially the same as the repetition case.

[0031] Thus, supporting repetition within the same slot can be considered as providing the same functionality as can be achieved by a single transmission with a longer TTI (Transmission Time Interval) length. Therefore, in order to support and specify PUSCH repetition within a slot, a better functionality should be achieved with more flexibility and advantages that cannot be achieved by the existing support for PUSCH transmission.

[0032] Therefore, it is desirable to improve minislot repetition within a slot to achieve more flexibility and advantages that cannot be achieved by a single allocation. Therefore, it is a proposal of this disclosure that for PUSCH mapping type B, repetition of PUSCH within the same slot should be supported only if additional functionality with more flexibility and advantages is achieved compared to the existing support for PUSCH transmission.

[0033] Such intra-slot repetition appears to provide similar functionality as a single allocation. However, if this is combined with other existing physical layer technologies, more flexibility with better benefits can be realized. In the following, some possible use cases are described that can only be realized if intra-slot repetition is supported.

[0034] For PUSCH mapping type B, frequency diversity gain can be further exploited if frequency hopping between repetitions is allowed within a slot. This gives the flexibility to schedule each repetition on two or more hops depending on the size of the bandwidth portion, as shown in Figure 7. Basically, more configurations are possible compared to a single transmission within a slot. Inter-frequency hopping can refer to hopping between subcarrier blocks, including for example 12 subcarriers (corresponding to the size of the resource block in the frequency domain). However, frequency hopping can also refer to bandwidth portion hopping. According to section 4.4.5 of TS 38.211 V15.0.0(2017-12), a bandwidth portion (or carrier bandwidth portion) is a set of contiguous physical resource blocks, as defined in clause 4.4.4.3, selected from a subset of contiguous common resource blocks, as defined in clause 4.4.4.2, for a given numerology on a given carrier.

[0035] Another advantage of using repetition within a slot is that each repetition can be transmitted on a different beam to achieve additional spatial diversity gains not possible with a single transmission, as shown in Figure 8. Beamforming allows the energy of a given radio transmission to be concentrated in a certain direction, thereby extending the range, for example, to compensate for high propagation losses at high frequencies. For example, if one transmission and three repetitions are allowed within a slot, up to four different beams can be utilized for each transmission, thus obtaining additional spatial diversity and potentially improved reliability.

[0036] In a configured grant (also known as grant-free) PUSCH, all allocated resources for the PUSCH may or may not belong to the uplink. Only symbols indicated as UL may be used. It may therefore occur that the number of symbols indicated as UL is not sufficient or contiguous to allow the transmission of a longer PUSCH. Thus, as shown in Figure 9, a shorter PUSCH can be scheduled more efficiently, and its repetitions within a slot can take advantage of the non-contiguous symbols available for the uplink.

[0037] It is a finding of the present disclosure that for PUSCH mapping type B, intra-slot repetition (i.e., the entire series of initial transmissions and repetitions performed in a single slot) can provide better flexibility and advantages in combination with other physical layer techniques such as frequency hopping and beam hopping by exploiting frequency and spatial diversity, respectively. It is further observed that for PUSCH mapping type B with configured grant, intra-slot repetition allows efficient use of measurement resources with a small number of UL symbols.

[0038] In conventional repetition, the same transport block (TB) is transmitted in the initial transmission and all repetitions round with the same DMRS setting. However, this may result in a suboptimal limit in terms of DMRS overhead. For example, as shown in Figure 10, for a 2-symbol PUSCH with initial transmission and 6 repetitions, the DMRS overhead is 50%, which is very high. For each repetition round, a minislot consists of 1 data symbol and 1 DMRS symbol in the TTI, which is very inefficient in terms of resource usage, because the DMRS symbol is very frequent over the slot period in which the initial transmission and all of the repetitions are performed.

[0039] Thus, it is observed that conventional repetition may result in a very large DMRS overhead in certain scenarios where the length of the PUSCH is very short. In other words, each repetition round corresponding to one of the subsequent TTIs / minislots consists of one data symbol and one DMRS symbol, which is very inefficient in terms of resource usage, since the DMRS symbol is very frequent over the slot period. Therefore, it is desirable to improve minislot repetition within a slot to improve delay and / or reliability compared to conventional repetition mechanisms.

[0040] On the other hand, even for high mobility UEs (ie, UEs that move at high speeds and therefore require frequent adaptation to rapidly changing channel characteristics), such a high density of DMRS is not necessarily required.

[0041] In view of the above findings and considerations, the present disclosure proposes to allow for a minislot repetition of data within a slot to modify or change the DMRS allocation / DMRS symbol allocation in at least one of the repetitions set by a signaling mechanism. To this end, proposed transmitting devices, receiving devices, transmitting methods and receiving methods are described in the following aspects and embodiments of the present disclosure.

[0042] It should be noted that although the motivation above has referred to the context of PUSCH repetition and further to NR URLLC as a service type, the present disclosure is not limited to a particular service type or communication channel / link, and in particular, as will be shown in the following description, the present disclosure is applicable to the downlink as well as the uplink.

[0043] Generally, the present disclosure provides a transmitting device 1110 for transmitting data to a receiving device 1160 over a channel (e.g., a wireless channel) in a communication system (particularly a wireless communication system). The transmitting device 1110 shown in FIG. 11 includes a processing circuit 1130 and a transceiver 1120. In operation, the processing circuit allocates data to a plurality of transmission time intervals (TTIs). Each of the plurality of TTIs includes a number of symbols less than a slot. Here, the data allocated to each TTI of the plurality of TTIs is identical. In addition to the data, a demodulation reference signal (DMRS) is allocated to an initial TTI of the plurality of TTIs. Furthermore, in operation, the circuit 1130 obtains, for each subsequent TTI of the plurality of TTIs following the initial TTI, a DMRS allocation indicating whether a DMRS is allocated to the TTI. In the present disclosure, a device or device part adapted or configured to perform a given task is referred to as "operating" to perform the given task. According to the described operation, the processing circuit 1130 includes a DMRS allocation obtainer 1231 and a DMRS / data allocator 1232, as shown in Fig. 12. The DMRS allocation obtainer 1231 obtains a DMRS allocation during operation. The DMRS / data allocator 1232 allocates data to multiple TTIs, allocates a DMRS to an initial TTI, and allocates or does not allocate a DMRS to a subsequent TTI according to the DMRS allocation obtained by the DMRS allocation obtainer 1231.

[0044] A DMRS allocation is an allocation scheme or allocation setting for a TTI that indicates whether a DMRS is allocated to this TTI. That is, the DMRS allocation indicates whether a DMRS is allocated to this TTI to be transmitted in addition to data. Thus, if the DMRS allocation for one of the subsequent TTIs indicates that a DMRS should be transmitted in this subsequent TTI, the DMRS is allocated to this subsequent TTI. However, if the DMRS allocation indicates that a DMRS should not be transmitted in this TTI, the DMRS is not allocated to this TTI.

[0045] The transceiver 1120 of the transmitting device (i.e., a transmitter and a receiver, meaning hardware and software components of the transmitting device and / or the receiving device adapted to transmit / receive a wireless signal and modulate / demodulate data assigned to time and frequency resources of the wireless signal) transmits data assigned to multiple TTIs to the receiving device in a slot during operation. Furthermore, the transceiver 1120 transmits a DMRS assigned to the initial TTI in an initial TTI, and performs DMRS transmission in one or more subsequent TTIs according to the obtained DMRS allocation. That is, on the one hand, in the subsequent TTI in which the DMRS is assigned, the DMRS and data are transmitted. On the other hand, in the subsequent TTI in which the DMRS is not assigned, the DMRS is not transmitted and data is transmitted.

[0046] The present disclosure further provides a receiving device 1160 for receiving data from a transmitting device 1110 over a channel (e.g., a wireless channel) in a communication system, such as a wireless system. The receiving device 1160 includes a circuit 1180 and a transceiver 1170. In operation, the receiving device circuit 1180 obtains a DMRS allocation for each subsequent TTI of one or more subsequent TTIs, i.e., each subsequent TTI following the initial TTI. Each of the multiple TTIs, including the initial TTI and the subsequent TTI, has a number of symbols less than a slot. The data allocated to each TTI of the multiple TTIs is identical. In accordance with the above description, the DMRS allocation for a TTI indicates whether a DMRS is allocated to this TTI to be received in addition to data. In operation, the transceiver 1170 of the receiving device 1160 receives, in a slot, data allocated to the initial TTI and the DMRS and data allocated to one or more subsequent TTIs from the transmitting device. DMRS reception in one or more subsequent TTIs is performed according to the DMRS allocation.

[0047] Corresponding to the above-mentioned transmitting device 1110 and receiving device 1160, a transmitting method and a receiving method shown in Fig. 13 are respectively provided. Both the transmitting method and the receiving method include an acquisition step (S1310, S1360) of acquiring a demodulation reference signal (DMRS) allocation for each of one or more subsequent TTIs following the initial TTI. The DMRS allocation indicates whether a DMRS is assigned to the subsequent TTI to be transmitted in addition to data. Each of the multiple TTIs including the initial TTI and the one or more subsequent TTIs includes a number of symbols less than a slot. The transmitting method further includes an assignment step (S1320) of assigning the same data to each TTI of the multiple TTIs, assigning a DMRS to the initial TTI, and, if indicated by the DMRS allocation, assigning a DMRS to one or more subsequent TTIs of the one or more subsequent TTIs. The transmitting method further includes a transmitting step (S1330) of transmitting data and a DMRS allocated to the initial TTI and data allocated to one or more subsequent TTIs to a receiving device, where the DMRS transmission in the one or more subsequent TTIs is performed according to the DMRS allocation. The receiving method includes a receiving step (S1370) of receiving data and a DMRS allocated to the initial TTI and data allocated to one or more subsequent TTIs in a slot from the transmitting device, where the DMRS reception in the one or more subsequent TTIs is performed according to the DMRS allocation.

[0048] As mentioned above, data and possibly reference signals are each assigned to a transmission time interval (TTI) smaller than a slot. Thus, the present disclosure is particularly related to the non-slot-based assignment described above. As mentioned above, in a non-slot-based assignment, the minimum length of a TTI may be conventionally 2 OFDM symbols. Such a 2-symbol TTI is illustrated in FIG. 10. A TTI smaller than a slot is referred to as a mini-slot in the present disclosure. However, this is not intended to limit the present disclosure to such terminology. In particular, due to the small size of the mini-slot TTI, the entire series of repetitions, including the initial transmission in the first two symbols (i.e., 1 DMRS symbol and 1 data symbol) and the six repetitions each including 1 DMRS symbol and 1 data symbol, fit into the slot, and therefore the entire series of repetitions are made within a single slot. Furthermore, the present disclosure also accommodates a TTI to which no DMRS is assigned, i.e., a TTI that does not include a DMRS symbol. Thus, if a DMRS symbol is removed from a minislot having only one data symbol, the minimum size of a TTI becomes one symbol instead of the two symbols previously assumed.

[0049] Within a DMRS-assigned TTI / minislot, the DMRS-assigned (DMRS) symbol precedes one or more symbols in which data is transmitted. The DMRS is used for channel estimation for coherent demodulation at the receiver side. In general, a TTI may also include multiple DMRS symbols for DMRS retransmissions that precede one or more data symbols in which data is transmitted.

[0050] However, in scenarios where the channel characteristics are not expected to change over the duration of one or two minislots in such a way that coherent demodulation is impaired, it may be sufficient to assign a DMRS symbol to the first TTI before one or more subsequent TTIs, but not to assign DMRS to the one or more subsequent TTIs. That is, in such cases, DMRS is not transmitted in at least one of the one or more subsequent TTIs / minislots following the initial TTI. This non-allocation of DMRS to subsequent TTIs within a slot may be done in use cases where the transmitting device is expected to be stationary or moving slowly, such as, for example, factory automation.

[0051] An example of flexible DMRS allocation for data repetitions is shown in Figure 14. This figure shows a slot containing 14 symbols. The first 10 symbols of this slot are occupied by a series of initial transmissions and repetitions. The initial transmission in the initial minislot corresponds to the first two symbols, followed by six data repetitions in six subsequent TTIs. In the first and fourth repetitions, further DMRS is transmitted, i.e., the first and fourth subsequent minislots both contain DMRS symbols in addition to data symbols. Thus, the DMRS allocations of the first and fourth subsequent TTIs, respectively, indicate that DMRS is transmitted in these TTIs. Meanwhile, according to the DMRS allocations of the TTIs corresponding to the second, third, fifth, and sixth repetitions, no DMRS is assigned to any of these TTIs.

[0052] An advantage of the transmitting / receiving device and transmitting / receiving method of the present disclosure is that flexible allocation and non-allocation of DMRS to minislots, such as flexible removal and / or replacement of DMRS in one or more data repetitions as described below, may enable configurations with additional advantages that are not possible with a single allocation (i.e., the same DMRS allocation for each TTI of a repetition) due to limitations of existing DMRS configurations.

[0053] As mentioned above, the DMRS allocation scheme for a minislot (i.e., a TTI having fewer symbols than a slot) indicates or specifies whether a DMRS is assigned to the minislot, and in particular to one or more symbols of the minislot (generally including the first symbol in time order). Thus, the DMRS allocation is also referred to as a DMRS symbol allocation in this disclosure. In the following, further details regarding possible DMRS symbol allocations are provided. In particular, if the DMRS symbol allocation for at least one TTI within a slot specifies that no DMRS is assigned to that TTI, then it is described how data is assigned to the respective symbols of the TTIs within the slot.

[0054] It has been described above that in a sequence of DMRS repetitions in minislots within a slot, no DMRS is assigned to the specific TTI in which the data repetition is performed. In particular, flexible DMRS assignment or modification of DMRS symbol assignment according to some embodiments of the present disclosure may mean: One or more DMRS symbols in a given repetition are removed, and only one or more data symbols are transmitted in each TTI corresponding to the given repetition. The flexible removal of one or more DMRS symbols in one or more repetitions can facilitate reducing delays to achieve a final target BLER compared to traditional repetitions (i.e., repetitions in which a DMRS is assigned to each TTI in which the repetition occurs). One or more DMRS symbols in a given repetition are replaced with one or more data symbols, and a transport block (TB) corresponding to the data to be transmitted is transmitted with a reduced coding rate relative to the initial transmission. The flexible replacement of one or more DMRS symbols in one or more repetitions can facilitate increased reliability compared to conventional repetitions. - Removal and replacement of one or more DMRS symbols are combined, which can facilitate providing both delay and reliability improvements compared to conventional repetition.

[0055] (DMRS removal) According to some embodiments, the DMRS allocation further indicates that if a DMRS is not assigned to a TTI, the length of this TTI is reduced by one or more symbols corresponding to the DMRS, which means that one or more DMRS symbols are removed in the TTI where the DMRS is not assigned.

[0056] Therefore, one possible extension to conventional repetitions is to allow flexibility to remove DMRS from certain repetitions depending on channel conditions and reliability requirements. As an example, if it is allowed to remove DMRS from certain repetitions in the case of an initial transmission and a 2-symbol PUSCH with 6 repetitions, one of the possibilities looks like the above-mentioned allocation of data and DMRS to TTIs shown in Figure 14. This flexibility not only allows to control DMRS overhead, but also gives more flexibility in terms of DMRS configuration, which is not currently supported in NR Rel. 15. Furthermore, by allowing such flexibility, the overall delay is also reduced.

[0057] The DMRS-less repetition rounds corresponding to minislots / TTIs without DMRS symbols use the last available DMRS for channel estimation. In particular, the second and third repetitions are DMRS-less and use the DMRS from the first repetition for demodulation. Similarly, the fifth and sixth repetitions are DMRS-less and use the DMRS from the fourth repetition for demodulation.

[0058] Regarding demodulation performance, especially in applications with low mobility requirements for the transmitting device such as the UE, there should be negligible difference for repetitions without DMRS, since the interval to the last available DMRS from the previous repetition is still rather small. Furthermore, the same MCS (Modulation and Coding Scheme), especially the same coding rate, may be used in the initial data transmission and in each repetition round, since the same amount of data symbols, e.g. one data symbol per transmission, is available in the initial TTI and in each subsequent TTI of one or more subsequent TTIs.

[0059] Such configurations (especially data / DMRS allocation to symbols within one slot) are not possible according to currently supported DMRS configurations for single assignments, and for such configurations performance may be similar or may be improved compared to current configurations for single transmissions.

[0060] Moreover, compared to conventional repetition, the delay can be reduced while still obtaining the same reliability. For example, as shown in Figure 14, the delay is reduced by 4 symbols.

[0061] Furthermore, resources (especially time domain resources) can be saved with respect to conventional repetition, where all 14 symbols of a slot are used for the initial transmission sequence and six repetitions, whereas according to the present embodiment some symbols in the slot (e.g. the last 4 symbols of the slot shown in Fig. 14) may not be used by the initial transmission sequence and repetitions and may be used for other transmissions, e.g. other URLLC traffic in queue for the same or other UEs.

[0062] Thus, with particular reference to PUSCH mapping type B discussed above, it is a further finding of the present disclosure that in a slot repetition for PUSCH mapping type B, removing the DMRS from certain repetition rounds can reduce DMRS overhead and provide more flexibility in terms of DMRS configuration, which is not currently possible in NR Rel. 15. An additional finding is that in a slot repetition for PUSCH mapping type B, removing the DMRS from certain repetition rounds can also reduce overall delay and make resources available for other traffic in the pipeline, e.g., URLLC / eMBB.

[0063] (Replacement for DMRS) According to some embodiments, the DMRS allocation for a subsequent TTI of one or more subsequent TTIs may further indicate that if a DMRS is not allocated in this subsequent TTI that is smaller than a slot, the symbols for the DMRS allocation in this subsequent TTI are replaced with symbols for the data allocation, i.e., in a minislot, the DMRS symbols are replaced with data symbols.

[0064] An exemplary allocation of DMRS and data to symbols of TTIs in a slot, where DMRS symbols are replaced with data symbols, is shown in FIG. 15. The slot includes seven minislots, with each minislot including two symbols. The first (initial) minislot, where the initial PUSCH transmission is performed, and the subsequent TTIs, where data for the first, third, and fifth repetitions are assigned, each include one DMRS symbol and one data symbol. However, the second, fourth, and sixth repetitions are each without a data symbol. In the TTIs corresponding to these repetitions, the DMRS is replaced with a data symbol, respectively. Thus, the second, fourth, and sixth subsequent minislots each include two data symbols, instead of one DMRS symbol followed by one data symbol.

[0065] The DMRS allocation scheme for repetitions within a slot allows the application of principles for reducing the MCS (i.e., coding rate) in a particular repetition to improve coding gain while maintaining the desired demodulation performance by avoiding long intervals between data symbols and DMRS. As can be seen from FIG. 15, in a TTI with two symbols, when DMRS symbols are replaced with data symbols, the number of symbols available for transmission doubles. Furthermore, in each repetition, identical data is transmitted. Thus, in the two-symbol example, the coding rate can essentially be reduced to half the coding rate of the initial data transmission in all repetitions where the change (i.e., replacement of DMRS symbols with data symbols) is applied. However, the present disclosure is not limited to TTIs with two symbols, so the reduced coding rate can also be other than half the original coding rate at which data is coded in the initial TTI and subsequent TTIs containing DMRS symbols.

[0066] 15, a configuration in which DMRS symbols are replaced by data symbols can obtain similar or even better performance compared to a single allocation, which is not possible according to current DMRS configurations. Moreover, compared to conventional repetition, the reliability can be further improved while keeping the delay the same.

[0067] As mentioned above, DMRS symbols may be removed or replaced from a particular TTI within a slot. For example, within a single slot or a series of slots, changes in DMRS symbol allocation may be limited to either DMRS symbol removal or DMRS symbol replacement. That is, within such a slot, only removal or only replacement is performed if DMRS is not assigned to one or more subsequent TTIs. However, as described in the following embodiments, DMRS symbol removal and replacement may be combined for different TTIs within a single slot.

[0068] (Combination of removal and replacement) For example, according to some embodiments, the DMRS allocation further indicates that if a DMRS is not assigned to a TTI, the length of this TTI is either reduced by one symbol corresponding to the DMRS (DMRS symbol removal) or the symbol for the DMRS assignment in this TTI is replaced by a symbol for the data assignment (DMRS symbol replacement). Thus, among one or more subsequent TTIs in which data is repeatedly transmitted within a slot, it is possible to configure that the DMRS symbol removal is applied to one subsequent TTI of the subsequent TTIs and the DMRS symbol replacement is applied to another subsequent TTI of the subsequent TTIs, regardless of the chronological order of these TTIs. That is, the TTI in which the DMRS symbol is removed may precede the TTI in which the DMRS symbol is replaced in transmission order, or vice versa.

[0069] A slot in which both removal and replacement of DMRS symbols are performed in different TTIs contained in the slot is shown in Figure 16. In particular, the second and fifth subsequent minislots, in which the second and fifth repetitions are performed, are free of DMRS symbols, and the length of these minislots is reduced accordingly. The third and sixth subsequent minislots, corresponding to the third and sixth repetitions, are also free of DMRS symbols, in which the DMRS symbols are replaced with further data symbols. For the third and sixth repetitions, each containing two data symbols, the code rate can be reduced by half, as mentioned above. Moreover, as can be further seen from this figure, the last two symbols of the slot in time order are not used for the initial series of transmissions and repetitions, and are therefore available for other traffic in the pipeline.

[0070] Such a mixed use of removal of DMRS symbols and replacement of DMRS symbols with data symbols can facilitate increased reliability and reduced delay relative to conventional repetition. Although removal of DMRS symbols can provide delay improvement, whereas replacement of DMRS symbols with reduced coding rate can facilitate increased reliability, a combination of these embodiments provides greater flexibility and allows tradeoffs between different objectives.

[0071] As mentioned above, in some embodiments, when symbols for DMRS assignment in a TTI are replaced with symbols for data assignment, the data is transmitted in this TTI at a lower code rate (or coding rate) than the code rate at which the data is transmitted in the initial TTI. For example, as shown, the lower code rate may be half the code rate at which the data transmitted in the initial TTI / minislot is coded, although this disclosure is not limited to reducing the coding rate by half. Alternatively, if the initial TTI includes 2 data symbols and 1 DMRS symbol and the subsequent TTI includes 3 data symbols and no DMRS symbols, the coding rate may be reduced to two-thirds of the coding rate used in the initial transmission. As mentioned above, the aforementioned reduction in coding rate should be understood as relative to the coding rate of the data in the initial TTI, rather than reducing the absolute coding rate 1 to, for example, 1 / 2. That is, the aforementioned reduction in coding rate is independent of the original value of the coding rate.

[0072] (Uplink transmission and repeat) Several examples have been shown in which a series of initial transmissions and repetitions constitute an uplink transmission, such as a PUSCH (Physical Uplink Shared Channel) transmission. Thus, in some embodiments, the transmitting device 1110 (specifically, the active transceiver 1120 of the transmitting device 1110) transmits data on the uplink to a receiving device, and the transceiver 1120 of the transmitting device 1110 further receives control signaling from the receiving device 1160. In response, the receiving device 1160 transmits control signaling to the transmitting device.

[0073] The control signaling includes an assignment indicator indicating a respective DMRS assignment for each of the subsequent TTIs of the subsequent TTIs. The circuitry 1130 of the transmitting device obtains the DMRS assignment for each of the subsequent TTIs of the initial TTI by evaluating the control signaling.

[0074] In an embodiment in which the transmitting device 1110 transmits data on the uplink to the receiving device 1160, the transmitting device may be a terminal or user equipment, and the receiving device 1160 may be a base station, referred to as a gNB or gNodeB in a NR (New Radio) communication system, which corresponds to an eNodeB (eNB) in a LTE (Long Term Evolution) or LTE-Advanced system. The data transmission on the uplink may correspond to an initial PUSCH transmission and one or more repetitions.

[0075] An uplink transmission method and an uplink reception method according to the present disclosure are shown in FIG. 17. As shown, a gNB corresponding to a receiving device 1160 obtains a DMRS by a decision step S1760 (embodied step S1360 of FIG. 13) for determining a DMRS allocation. In particular, such decision of the DMRS allocation is performed based on a channel quality estimation. In particular, the base station can estimate the channel quality based on an uplink sounding reference signal (SRS) transmitted by the UE for the purpose of channel quality estimation. The gNB can receive the SRS from one or more UEs and determine the DMRS allocation based on a channel condition corresponding to the channel quality estimated based on the received SRS.

[0076] The gNB / base station then generates a DMRS allocation indicator and transmits control signaling including the DMRS allocation indicator to the (user) terminal in step S1765. The user terminal receives the control signaling including the DMRS allocation indicator in step S1710 (embodied as step S1310 of FIG. 13), thereby obtaining the DMRS allocation. The assignment step S1320 and transmission step S1330 of the uplink transmission method and the reception step S1370 of the uplink reception method are performed according to the corresponding general method shown in FIG. 13.

[0077] (Control Signaling) Specifically, in some embodiments, the DMRS allocation indicator for each of the one or more subsequent TTIs is a two-bit allocation indicator. Two bits are sufficient to indicate whether a DMRS is allocated to the TTI and further indicate whether the option of DMRS removal or DMRS replacement is applied. Thus, each repetition may be associated with one of the following two-bit indications, respectively: - "00": No change to one or more DMRS symbols in a given repetition (i.e., DMRS is assigned to the TTI) "01": One or more DMRS symbols are removed, reducing the TTI length of a given repetition "10": One or more DMRS symbols are replaced with one or more data symbols to reduce the coding rate for a given iteration - "11": reserved entry

[0078] According to the above 2-bit indication, the DMRS allocation indicator for 6 repetitions consists of six 2-bit indicators. For the example of combined DMRS symbol removal and replacement shown in Figure 16, the resulting 12-bit indicator is "00 01 10 00 01 10". This indicator is also shown in Figure 18.

[0079] Obviously, the association between the two-bit values ​​and the DMRS allocations is merely exemplary. Alternatively, for example, "10" may represent DMRS symbol cancellation.

[0080] Alternatively, the DMRS allocation indicator may have more or less than two bits. Specifically, the DMRS allocation indicator for each subsequent TTI transmitted in the slot may be a one-bit indicator, resulting in a six-bit field for indication of DMRS allocation for up to six retransmissions. If it is clear or known, for example from the standard or from further control signaling, what specific changes are made to the allocation in the TTI (e.g., whether removal or replacement of DMRS symbols is performed), then a one-bit indicator corresponding to the TTI is sufficient to indicate whether DMRS is allocated to this TTI or not. For example, a bit value of "0" may indicate that DMRS is allocated to the TTI and transmitted in this TTI, and a bit value of "1" may indicate that DMRS is not allocated, regardless of whether DMRS symbols are replaced or removed. Thus, the resulting 6-bit DMRS allocation indicator for all six repetitions would be "011011" for the example shown in Figure 14 (removal) and "010101" for the example shown in Figure 15 (substitution). Again, the "0" and "1" values ​​may be reversed, with a "1" value in this case signifying allocation of the DMRS to the TTI.

[0081] For example, a DMRS allocation indicator (e.g., the above-mentioned 1-bit indicator or 2-bit indicator for each TTI) may be included in higher-level signaling. Thus, the DMRS allocation is signaled semi-statically, specifically in RRC (Radio Resource Control) signaling.

[0082] In some embodiments, the control signaling further includes a DMRS activation indicator indicating whether a DMRS is not allocated to any of one or more subsequent TTIs. Thus, the DMRS activation indicator, which may be a one-bit indicator, may indicate whether flexible recurrence configuration (whether a DMRS is allocated to a subsequent TTI or not, as well as the type of case where it is not allocated) applies or not. In other words, the DMRS activation indicator is set to disable or enable flexible DMRS configuration. Furthermore, the selection of a particular DMRS activation indicator may indicate the degree of flexibility in DMRS allocation.

[0083] Specifically, the DMRS enablement indicator may be a one-bit indicator indicating whether flexible DMRS is applied within a slot or within a longer time interval including several slots (e.g., the enablement indicator may be signaled semi-statically, as described below). For example, "0" indicates that flexible repetition that allows no DMRS to be assigned to a particular TTI is not applied, and "1" indicates that flexible repetition is applied (or vice versa). The one-bit enablement indicator may be used in combination with a respective two-bit indicator for a particular group of TTIs of the above-mentioned set of repetitions. For example, if the DMRS enablement indicator indicates that flexible DMRS is applied, the two-bit indicator may specify whether DMRS allocation, DMRS removal, or DMRS replacement is applied for a particular TTI within the slot.

[0084] Alternatively, the 1-bit enable indicator may indicate whether DMRS removal or DMRS replacement is applied (e.g., "0" indicates removal and "1" indicates replacement). In this case, whether a DMRS is not allocated (specifically, removed or replaced depending on the value of the DMRS enable indicator) may be indicated by the 1-bit DMRS allocation indicator for each TTI.

[0085] The activation indicator may be included in higher layer signaling. Alternatively, the activation indicator may be included in downlink control information (DCI) (i.e., a physical layer control signaling message transmitted on the PDCCH (Physical Downlink Control Channel)), which may be considered as dynamic signaling for conveying, for example, scheduling information (grant) and / or transmission parameters. The present disclosure is not limited to a specific DCI format, which may correspond to an existing / specified DCI format for NR or may be agreed in the future for a specific service type such as URLLC. On the one hand, including the activation indicator in the DCI provides greater flexibility, since enabling / disabling of DMRS allocation can be performed with grants for a flexible set of data repetitions. On the other hand, signaling the activation indicator in higher layer signaling rather than in the DCI can avoid introducing further DCI signaling and thus resulting in DCI signaling overhead. However, when the DMRS allocation indicator is included in the DCI, advantageously a one-bit allocation indicator is used.

[0086] The above mentioned control signaling including the DMRS allocation indicator for each TTI and the activation indicator constitute a signaling mechanism that can be implemented with only RRC signaling (semi-static configurability), however, the signaling mechanism may also be implemented as a combination of both RRC and DCI signaling, as described below.

[0087] In the case where DMRS allocation / activation configuration is done solely by RRC signaling, a two-bit field (referred to as "Bit Field 1" and "Bit Field 2" in this disclosure) may allow complete flexibility to allow removal or replacement of DMRS symbols in any of the repetition rounds (i.e., flexibly specifying in what order removal, replacement, or allocation, respectively, is performed within a series of repetitions).

[0088] Bit field 1 may correspond to the above mentioned 1-bit enable indicator indicating whether flexible repetition configuration is applied or not. The exact repetition configuration (DMRS allocation) is configurable by bit field 2 corresponding to a 2-bit allocation indicator provided respectively for the TTI. In bit field 2, the maximum number of bits is twice the maximum allowed number of repetitions. For example, if a maximum of 6 repetitions are allowed, a 12-bit field is defined in RRC to allow flexible repetition configuration. Each repetition (i.e. each subsequent TTI) is associated with 2 bits having an indication as listed above in the description of the DMRS allocation indicator. Thus, returning to the example of the combination of DMRS removal and DMRS replacement shown in Figure 16, bit field 1 has the value "1" (indicating that flexible repetition is applied) and bit field 2 takes the value "00 01 10 00 01 10" as described above and shown in Figure 18.

[0089] As an alternative to bit field 1 being a 1-bit field and bit field 2 being a field of up to 12 bits, a 1-bit enable indicator indicating whether DMRS substitution or DMRS removal is applied may be combined with the respective 1-bit DMRS allocation indicator for the subsequent TTIs as described above. As a further alternative, a 2-bit enable indicator as described above may be combined with the respective 1-bit allocation indicator. In the latter signaling mechanism, bit field 2 of up to 12 bits may be reduced by half the bits to a field of up to 6 bits. Thus, resources in RRC signaling are saved.

[0090] Furthermore, in accordance with the present disclosure, signaling of one or more DMRS assignments for each TTI corresponding to repetition may be performed without bit field 1. Specifically, control signaling related to DMRS assignment may include only a DMRS assignment indicator. However, if an enablement indicator is included in the RRC control signaling and indicates a value of "0" (flexible repetition is not applied), bit field 2 does not need to be signaled in the same RRC signaling and bits may be reused or saved for indications other than DMRS assignment.

[0091] As an alternative to control signaling of DMRS allocation / activation in RRC only, the signaling mechanism may include both RRC signaling and DCI signaling, which may allow some degree of dynamicity of DMRS allocation.

[0092] Specifically, a field called "bit field 1" may be moved to the DCI, i.e. a 1-bit field corresponding to one of the 1-bit enable indicators mentioned above is added to the DCI to dynamically signal whether flexible repetition configuration (which in this case is still configurable by the RRC bit field) is applied or not (DCI bit field value "1" if flexible repetition configuration is applied, and "0" if flexible repetition configuration is not applied). In case control signaling in RRC and control signaling in DCI are combined, the RRC bit field in RRC signaling may be the same as "bit field 2" mentioned above for RRC only use. Thus, the repetition configuration pattern (i.e. DMRS allocation for each subsequent TTI) is the same, but its application (i.e. activation (deactivation) to "switch" flexible DMRS allocation on or off) is dynamically done via the DCI.

[0093] The one-bit field in the DCI may be a one-bit enable indicator specifying the enablement or disablement of flexible DMRS allocation, as described above. In this case, the bit field in the RRC signaling may correspond to a two-bit DMRS allocation indicator as described above (up to 12 bits for up to 6 repetitions), which also indicates whether DMRS symbol substitution or DMRS symbol removal is applied. However, the one-bit field in the DCI may also correspond to the above-mentioned indicator indicating whether DMRS removal or DMRS substitution is applied. In this case, the DMRS allocation indicator may have one bit per subsequent TTI (up to 6 bits for up to 6 repetitions), as described above. As a further alternative, the type of symbol allocation (substitution or removal) in case DMRS is not assigned to the repetition may be predefined, for example by a standard. In this case, a one-bit enable indicator in the DCI and a one-bit DMRS allocation indicator per subsequent TTI (e.g. 6 bits corresponding to 6 repetitions) are sufficient.

[0094] Further embodiments Some of the above embodiments have been described specifically in relation to uplink transmission / repetition. However, as already mentioned, the present disclosure is not limited to the uplink case and may be used in relation to PDSCH repetition. Thus, in some embodiments, the transmitting device, rather than the receiving device, corresponds to a gNB. The transmitting device generates a DMRS allocation indicator and optionally an activation indicator, and transmits control signaling including the DMRS allocation indicator to the receiving device (i.e., a (user) terminal). The receiving device receives the DMRS allocation indicator (and possibly an activation indicator), and further receives data in an initial TTI and receives DMRS in a subsequent TTI according to the DMRS allocation indicated by the received DMRS allocation indicator (and possibly an activation indicator). Here, the activation indicator and the allocation indicator may correspond to any of the indicators described above for the uplink case.

[0095] Furthermore, it should be noted that the present disclosure is directed to enabling flexibility in the time domain: the allocation of data and DMRS to carriers or subcarriers, i.e., to resources in the frequency domain of an OFDM system, or to other resources such as spatial resources (beams), is not affected by the DMRS allocation.

[0096] However, the flexibility in repetition as described in this disclosure can also be utilized in frequency hopping, beam hopping, and small measurement resource scenarios, as shown in Figures 19-21. The same phase is used to utilize the DMRS from the last available transmission for channel estimation in the current repetition round. In the case of frequency hopping, channel estimation can be performed from the last available DMRS in the same hop. Similarly, in the case of beam hopping, channel estimation can be performed from the last available DMRS in the same beam.

[0097] Thus, in some embodiments, as shown in FIG. 19, during operation, the transceiver transmits data assigned to each of the one or more subsequent TTIs on a set of subcarriers different from the set of subcarriers on which the data was transmitted in the TTI immediately preceding the subsequent TTI of the plurality of TTIs. In other words, in two of the plurality of TTIs, the data is assigned to a different set of subcarriers and transmitted on a different set of subcarriers. The set of subcarriers may correspond to 12 subcarriers corresponding to the resource block size in the frequency domain or may correspond to the bandwidth portion mentioned above. Thus, frequency hopping may be performed before each subsequent TTI to which the DMRS is assigned. However, when frequency hopping is performed from one TTI to the next TTI of the plurality of TTIs, the data in the TTI after the frequency hopping step / operation is transmitted on the set of subcarriers on which the DMRS was transmitted in the one TTI of the plurality of TTIs prior to the TTI after the hopping step. In FIG. 19, frequency hopping between two respective frequency groups / sets is performed.

[0098] Similar to the frequency hopping described above, in some embodiments, as shown in Figure 20, the transceiver transmits data assigned to each of one or more subsequent TTIs in operation on a beam different from the beam in which the data was transmitted in the TTI immediately preceding the subsequent TTI of the plurality of TTIs. That is, in two of the plurality of TTIs, the data is transmitted on different beams. As with frequency hopping, in each TTI, the data is transmitted on the beam in which the data was previously transmitted in another TTI of the plurality of TTIs. In the example of beam hopping shown in Figure 20, beam hopping between two different beams is performed.

[0099] The beam or frequency change from one TTI to the next may be signaled semi-statically. For example, in addition to the DMRS allocation indicator, the RRC signaling may also include a beam hopping pattern indicator or a frequency hopping pattern indicator. Furthermore, the DCI or RRC may include a beam hopping activator and / or a frequency hopping indicator. Alternatively, for the case where flexible DMRS allocation is enabled, a predefined hopping pattern may be defined in the standard.

[0100] In some further embodiments, the multiple TTIs in which data is assigned to be transmitted in the initial transmission and repetitions are not consecutive. That is, between two of the multiple TTIs there are symbols that are not included in any of the multiple TTIs. That is, other data and / or control signaling different from the data assigned to each TTI of the multiple TTIs may be assigned to the symbols between two of the multiple TTIs. An example is shown in Figure 21, where there is an initial PUSCH transmission and three data repetitions in a slot, and a DMRS is assigned to the TTIs corresponding to the initial transmission and the second repetition. However, between each of these TTIs there are symbols that are not used for the same set of initial transmissions and repetitions. Furthermore, these intervening symbols are symbols that are not used for uplink transmissions.

[0101] Additionally, in most of the examples shown, the initial transmission begins with the DMRS assigned to the first symbol of the slot. However, particularly in accordance with PUSCH mapping type B described above, the present disclosure is not limited to an initial TTI that includes the first symbol in the slot in chronological order. Alternatively, the initial transmission may begin with a symbol other than the first symbol in the slot.

[0102] The present disclosure can be realized by software, by hardware, or by software cooperating with hardware. Each functional block used in the description of each embodiment above can be realized in part or in whole by an LSI such as an integrated circuit, and each process described in each embodiment can be controlled in part or in whole by the same LSI or a combination of LSIs. The LSI can be formed individually as a chip, or one chip can be formed to include some or all of the functional blocks. The LSI can include a data input / output unit coupled to it. Depending on the degree of integration, the LSI may be called an IC, a system LSI, a super LSI, or an ultra LSI. However, the technology for realizing an integrated circuit is not limited to an LSI, and can be realized by using a dedicated circuit, a general-purpose processor, or a dedicated processor. In addition, an FPGA (field programmable gate array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connection and settings of the circuit cells arranged inside the LSI, can also be used. The present disclosure can be realized as digital processing or analog processing. When LSI is replaced by a future integrated circuit technology as a result of advances in semiconductor technology or other derivative technologies, the future integrated circuit technology can be used to integrate the functional blocks. Biotechnology can also be applied.

[0103] According to one general aspect, the present disclosure provides a transmitting device for transmitting data to a receiving device in a communication system, the transmitting device comprising: circuitry for, during operation, allocating the data to a plurality of transmission time intervals (TTIs) including an initial TTI and one or more subsequent TTIs following the initial TTI, and further allocating a demodulation reference signal (DMRS) to the initial TTI, and for each of the one or more subsequent TTIs, obtaining a DMRS allocation indicating whether a DMRS is allocated to the subsequent TTI to be transmitted in addition to the data, wherein each of the plurality of TTIs includes a number of symbols less than a slot, and the data allocated to each TTI of the plurality of TTIs is identical; and a transceiver for, during operation, transmitting within the slot the data allocated to the initial TTI and the DMRS and the data allocated to the one or more subsequent TTIs to the receiving device, wherein DMRS transmission in the one or more subsequent TTIs is performed in accordance with the DMRS allocation.

[0104] This provides greater flexibility for repetition and facilitates enabling reduced delays and / or increased reliability.

[0105] For example, the DMRS is not transmitted in at least one subsequent TTI of the one or more subsequent TTIs.

[0106] In some embodiments, the DMRS allocation further indicates that if a DMRS is not assigned to that subsequent TTI, then the length of that subsequent TTI is reduced by one symbol corresponding to that DMRS.

[0107] This facilitates reducing delays.

[0108] In another embodiment, the DMRS allocation further indicates that if a DMRS is not allocated in the subsequent TTI, then symbols for the DMRS allocation in the subsequent TTI are replaced with symbols for the data allocation.

[0109] This facilitates enhanced reliability.

[0110] In a further embodiment, the DMRS allocation further indicates either that if a DMRS is not allocated in the subsequent TTI, the length of the subsequent TTI is reduced by one symbol corresponding to the DMRS, or that the symbols for allocation of the DMRS in the subsequent TTI are replaced with symbols for allocation of the data.

[0111] This helps to reduce delays and enhance reliability.

[0112] For example, if the symbols for allocating the DMRS in the subsequent TTI are replaced with symbols for allocating the data, the data is transmitted in the subsequent TTI at a code rate lower than the code rate at which the data is transmitted in the initial TTI.

[0113] For example, the transmitting device transmits the data to the receiving device on an uplink, and the transceiver, during operation, further receives control signaling from the receiving device, the control signaling including a DMRS allocation indicator indicating the DMRS allocation for each subsequent TTI of the one or more subsequent TTIs, and the circuit, during operation, obtains the DMRS allocation for each subsequent TTI of the one or more subsequent TTIs by evaluating the control signaling.

[0114] For example, the DMRS allocation indicator for each subsequent TTI is a two-bit allocation indicator.

[0115] In some embodiments, the DMRS allocation indicator is included in higher layer signaling.

[0116] For example, the control signaling further includes a validation indicator that indicates whether a DMRS is not assigned to any of the one or more subsequent TTIs.

[0117] In some exemplary embodiments, the activation indicator is included in higher layer signaling.

[0118] This results in avoiding additional physical layer signaling overhead.

[0119] In another exemplary embodiment, the validation indicator is a one-bit indicator included in downlink channel information (DCI).

[0120] This allows for flexible dynamic switching of DMRS allocation.

[0121] In some embodiments, the transmitting device transmits the data to the receiving device on a downlink, and during operation, the transceiver further transmits control signaling to the receiving device for each subsequent TTI of the one or more subsequent TTIs, the control signaling including a DMRS allocation indicator indicating the DMRS allocation.

[0122] For example, in two of the TTIs, the data is assigned to a different set of subcarriers and transmitted on the different set of subcarriers.

[0123] For example, in two of the multiple TTIs, the data is transmitted in different beams.

[0124] In some embodiments, a symbol between two of the plurality of TTIs is not included in any of the plurality of TTIs.

[0125] According to another general aspect, there is provided a receiving device for receiving data from a transmitting device in a communication system, the receiving device comprising: circuitry for obtaining, during operation, a DMRS assignment indicating, for each of one or more subsequent TTIs following an initial transmission time interval (TTI), whether a demodulation reference signal (DMRS) is assigned to the subsequent TTI to be received in addition to the data, wherein each of a plurality of TTIs including the initial TTI and the one or more subsequent TTIs includes a number of symbols less than a slot, a DMRS is assigned to the initial TTI, and the data assigned to each TTI of the plurality of TTIs is identical; and a transceiver for receiving, during operation, from the transmitting device, the data assigned to the initial TTI and the DMRS and the data assigned to the one or more subsequent TTIs within the slot, wherein DMRS reception in the one or more subsequent TTIs is performed in accordance with the DMRS assignment.

[0126] For example, the DMRS is not transmitted in at least one subsequent TTI of the one or more subsequent TTIs.

[0127] In some embodiments, the DMRS allocation further indicates that if a DMRS is not assigned to that subsequent TTI, then the length of that subsequent TTI is reduced by one symbol corresponding to that DMRS.

[0128] In another embodiment, the DMRS allocation further indicates that if a DMRS is not allocated in the subsequent TTI, then symbols for the DMRS allocation in the subsequent TTI are replaced with symbols for the data allocation.

[0129] In a further embodiment, the DMRS allocation further indicates either that if a DMRS is not allocated in the subsequent TTI, the length of the subsequent TTI is reduced by one symbol corresponding to the DMRS, or that the symbols for allocation of the DMRS in the subsequent TTI are replaced with symbols for allocation of the data.

[0130] For example, if the symbols for allocating the DMRS in the subsequent TTI are replaced with symbols for allocating the data, the data is transmitted in the subsequent TTI at a code rate lower than the code rate at which the data is transmitted in the initial TTI.

[0131] For example, the receiving device receives the data on an uplink from the transmitting device and further transmits control signaling to the transmitting device including a DMRS allocation indicator indicating the DMRS allocation for each subsequent TTI of the one or more subsequent TTIs.

[0132] For example, the DMRS allocation indicator for each subsequent TTI is a two-bit allocation indicator.

[0133] In some embodiments, the DMRS allocation indicator is included in higher layer signaling.

[0134] For example, the control signaling further includes a validation indicator that indicates whether a DMRS is not assigned to any of the one or more subsequent TTIs.

[0135] In some exemplary embodiments, the activation indicator is included in higher layer signaling.

[0136] In another exemplary embodiment, the validation indicator is a one-bit indicator included in downlink channel information (DCI).

[0137] In some embodiments, the receiving device receives the data from the transmitting device on a downlink, and the transceiver, during operation, further receives control signaling from the transmitting device, the control signaling including a DMRS allocation indicator indicating the DMRS allocation for each subsequent TTI of the one or more subsequent TTIs, and the circuit, during operation, obtains the DMRS allocation for each subsequent TTI of the one or more subsequent TTIs by evaluating the control signaling.

[0138] For example, in two of the TTIs, the data is assigned to a different set of subcarriers and is received on the different set of subcarriers.

[0139] For example, in two of the multiple TTIs, the data is received in different beams.

[0140] In some embodiments, a symbol between two of the plurality of TTIs is not included in any of the plurality of TTIs.

[0141] In another general aspect, the present disclosure provides a method for a transmitting device transmitting data to a receiving device in a communication system, the method including: obtaining, for each of one or more subsequent transmission time intervals (TTIs) following an initial TTI, a DMRS assignment indicating whether a demodulation reference signal (DMRS) is assigned to the subsequent TTI to be transmitted in addition to the data, where each of a plurality of TTIs including the initial TTI and the one or more subsequent TTIs includes a number of symbols less than a slot; assigning the same data to each of the plurality of TTIs and assigning a DMRS to the initial TTI; and transmitting, within the slot, the data and the DMRS assigned to the initial TTI and the data assigned to the one or more subsequent TTIs to the receiving device, where the DMRS transmission in the one or more subsequent TTIs is performed in accordance with the DMRS assignment.

[0142] For example, the DMRS is not transmitted in at least one subsequent TTI of the one or more subsequent TTIs.

[0143] In some embodiments, the DMRS allocation further indicates that if a DMRS is not assigned to that subsequent TTI, then the length of that subsequent TTI is reduced by one symbol corresponding to that DMRS.

[0144] In another embodiment, the DMRS allocation further indicates that if a DMRS is not allocated in the subsequent TTI, then symbols for the DMRS allocation in the subsequent TTI are replaced with symbols for the data allocation.

[0145] In a further embodiment, the DMRS allocation further indicates either that if a DMRS is not allocated in the subsequent TTI, the length of the subsequent TTI is reduced by one symbol corresponding to the DMRS, or that the symbols for allocation of the DMRS in the subsequent TTI are replaced with symbols for allocation of the data.

[0146] For example, if the symbols for allocating the DMRS in the subsequent TTI are replaced with symbols for allocating the data, the data is transmitted in the subsequent TTI at a code rate lower than the code rate at which the data is transmitted in the initial TTI.

[0147] For example, the data is transmitted on an uplink to the receiving device, and the transmission method further includes receiving from the receiving device, for each subsequent TTI of the one or more subsequent TTIs, control signaling including a DMRS allocation indicator indicating the DMRS allocation, and in the obtaining step, the DMRS allocation is obtained for each subsequent TTI of the one or more subsequent TTIs by evaluating the control signaling.

[0148] For example, the DMRS allocation indicator for each subsequent TTI is a two-bit allocation indicator.

[0149] In some embodiments, the DMRS allocation indicator is included in higher layer signaling.

[0150] For example, the control signaling further includes a validation indicator that indicates whether a DMRS is not assigned to any of the one or more subsequent TTIs.

[0151] In some exemplary embodiments, the activation indicator is included in higher layer signaling.

[0152] In another exemplary embodiment, the validation indicator is a one-bit indicator included in downlink channel information (DCI).

[0153] In some embodiments, the data is transmitted to the receiving device on a downlink, and the transmitting method further includes transmitting control signaling to the receiving device for each subsequent TTI of the one or more subsequent TTIs, the control signaling including a DMRS allocation indicator indicating the DMRS allocation.

[0154] For example, in two of the TTIs, the data is assigned to a different set of subcarriers and transmitted on the different set of subcarriers.

[0155] For example, in two of the multiple TTIs, the data is transmitted in different beams.

[0156] In some embodiments, a symbol between two of the plurality of TTIs is not included in any of the plurality of TTIs.

[0157] According to another general aspect, the present disclosure provides a receiving method for a receiving device receiving data from a transmitting device in a communication system, the receiving method including: obtaining, for each of one or more subsequent transmission time intervals (TTIs) following an initial TTI, a DMRS assignment indicating whether a demodulation reference signal (DMRS) is assigned to the subsequent TTI to be received in addition to the data, wherein each of a plurality of TTIs including the initial TTI and the one or more subsequent TTIs includes a number of symbols less than a slot, a DMRS is assigned to the initial TTI, and the data assigned to each TTI of the plurality of TTIs is identical; and receiving from the transmitting device, within the slot, the data assigned to the initial TTI and the DMRS and the data assigned to the one or more subsequent TTIs, wherein DMRS reception in the one or more subsequent TTIs is performed in accordance with the DMRS assignment.

[0158] For example, the DMRS is not transmitted in at least one subsequent TTI of the one or more subsequent TTIs.

[0159] In some embodiments, the DMRS allocation further indicates that if a DMRS is not assigned to that subsequent TTI, then the length of that subsequent TTI is reduced by one symbol corresponding to that DMRS.

[0160] In another embodiment, the DMRS allocation further indicates that if a DMRS is not allocated in the subsequent TTI, then symbols for the DMRS allocation in the subsequent TTI are replaced with symbols for the data allocation.

[0161] In a further embodiment, the DMRS allocation further indicates either that if a DMRS is not allocated in the subsequent TTI, the length of the subsequent TTI is reduced by one symbol corresponding to the DMRS, or that the symbols for allocation of the DMRS in the subsequent TTI are replaced with symbols for allocation of the data.

[0162] For example, if the symbols for allocating the DMRS in the subsequent TTI are replaced with symbols for allocating the data, the data is transmitted in the subsequent TTI at a code rate lower than the code rate at which the data is transmitted in the initial TTI.

[0163] For example, the data is received from the transmitting device on an uplink, and the receiving method further includes transmitting control signaling to the transmitting device, the control signaling including a DMRS allocation indicator indicating the DMRS allocation, for each subsequent TTI of the one or more subsequent TTIs.

[0164] For example, the DMRS allocation indicator for each subsequent TTI is a two-bit allocation indicator.

[0165] In some embodiments, the DMRS allocation indicator is included in higher layer signaling.

[0166] For example, the control signaling further includes a validation indicator that indicates whether a DMRS is not assigned to any of the one or more subsequent TTIs.

[0167] In some exemplary embodiments, the activation indicator is included in higher layer signaling.

[0168] In another exemplary embodiment, the validation indicator is a one-bit indicator included in downlink channel information (DCI).

[0169] In some embodiments, the data is received on a downlink from the transmitting device, and the receiving method further includes receiving, for each subsequent TTI of the one or more subsequent TTIs, control signaling from the transmitting device including a DMRS allocation indicator indicating the DMRS allocation, and in the obtaining step, the DMRS allocation for each subsequent TTI of the one or more subsequent TTIs is obtained by evaluating the control signaling.

[0170] For example, in two of the TTIs, the data is assigned to a different set of subcarriers and is received on the different set of subcarriers.

[0171] For example, in two of the multiple TTIs, the data is received in different beams.

[0172] In some embodiments, a symbol between two of the plurality of TTIs is not included in any of the plurality of TTIs.

[0173] In summary, the present disclosure relates to a transmitting device for transmitting data to a receiving device in a communication system. The transmitting device includes a circuit for, during operation, allocating data to a plurality of transmission time intervals (TTIs), including an initial TTI and one or more subsequent TTIs following the initial TTI, allocating a demodulation reference signal (DMRS) to the initial TTI, and obtaining, for each of the one or more subsequent TTIs, a DMRS allocation indicating whether a DMRS is allocated to the subsequent TTI for transmission in addition to data. Each of the plurality of TTIs includes a number of symbols less than a slot, and the data allocated to each TTI of the plurality of TTIs is identical. The transmitting device further includes a transceiver for, during operation, transmitting data within the slot and transmitting the DMRS according to the DMRS allocation.

Claims

1. A transmitting device for transmitting data to a receiving device in a communication system, comprising: and a circuit for, during operation, allocating the data repetitions, including an initial transmission and one or more subsequent transmissions, and a demodulation reference signal (DMRS) to a time domain resource and obtaining a DMRS allocation indicating whether a DMRS is allocated to the time domain resource, wherein each of the data repetitions includes a number of consecutive symbols that is less than a slot; a transceiver configured to, in operation, transmit the data and the DMRS to the receiving device within the slot, the transmission of the DMRS in the data repetition being performed in accordance with the DMRS allocation; Equipped with symbols during the data repetitions are assigned symbols that are not valid for uplink transmission; Sending device.

2. no DMRS is transmitted in at least one subsequent transmission of the one or more subsequent transmissions; The transmitting device according to claim 1 .

3. The DMRS assignment may further indicate that if a DMRS is not assigned to the subsequent transmission, then the length of the subsequent transmission is reduced by one symbol corresponding to the DMRS. A transmitting device according to claim 1 or 2.

4. the transmitting device transmits the data to the receiving device on an uplink; During operation, the transceiver further receives control signaling from the receiving device, the control signaling including a DMRS assignment indicator indicating the DMRS assignment for the data repetition; and wherein, during operation, the circuitry obtains the DMRS assignment for each repetitive transmission of the data by evaluating the control signaling. The transmitting device according to claim 1 .

5. The DMRS allocation indicator for each transmission of the data repetition is a 2-bit allocation indicator. A transmitting device according to claim 4.

6. The DMRS allocation indicator is included in higher layer signaling. A transmitting device according to claim 4.

7. The control signaling further includes a validation indicator indicating whether a DMRS is not assigned to any of the data repetitions. A transmitting device according to claim 4.

8. The activation indicator is included in higher layer signaling. A transmitting device according to claim 7.

9. The activation indicator is a one-bit indicator included in downlink control information (DCI). A transmitting device according to claim 7.

10. A receiving device for receiving data from a transmitting device in a communication system, comprising: and a circuit for, during operation, allocating the data repetitions, including an initial transmission and one or more subsequent transmissions, and a demodulation reference signal (DMRS) to a time domain resource and obtaining a DMRS allocation indicating whether the DMRS is allocated to the time domain resource, each of the data repetitions including a number of consecutive symbols that is less than a slot; a transceiver configured to receive, in operation, the data and the DMRS from the transmitting device in the slot, wherein reception of the DMRS in the data repetition is performed according to the DMRS allocation; Equipped with symbols during the time domain resources are assigned symbols that are not valid for uplink transmission; The receiving device.

11. 1. A method for a transmitting device in a communication system for transmitting data to a receiving device, comprising: assigning the data repetitions, including an initial transmission and one or more subsequent transmissions, and a demodulation reference signal (DMRS) to time domain resources, each of the data repetitions including a number of consecutive symbols less than a slot; obtaining a DMRS allocation indicating whether the DMRS is allocated to the time domain resource; transmitting the data and the DMRS to the receiving device within the slot, where the transmission of the DMRS in the data repetition is performed in accordance with the DMRS allocation; Including, symbols during the time domain resources are assigned symbols that are not valid for uplink transmission; Transmission method.

12. 1. A method for a receiving device receiving data from a transmitting device in a communication system, comprising: assigning repetitions of the data, including an initial transmission and one or more subsequent transmissions, and a demodulation reference signal (DMRS) to a time domain resource and obtaining a DMRS assignment indicating whether the DMRS is assigned to the time domain resource, each of the repetitions including a number of consecutive symbols less than a slot; receiving, from the transmitting device, the data and the DMRS in the slot, where the reception of the DMRS in the data repetition is performed in accordance with the DMRS allocation; Including, symbols during the time domain resources are assigned symbols that are not valid for uplink transmission; Receiving method.

13. 1. An integrated circuit for controlling processing of a transmitting device for transmitting data to a receiving device in a communication system, the processing comprising: a process of allocating the data repetitions, including an initial transmission and one or more subsequent transmissions, and a demodulation reference signal (DMRS) to a time domain resource and obtaining a DMRS allocation indicating whether the DMRS is allocated to the time domain resource, the data repetitions each including a number of consecutive symbols less than a slot; a process of transmitting the data and the DMRS to the receiving device within the slot, the transmission of the DMRS in the data repetition being performed according to the DMRS allocation; Including, symbols during the time domain resources are assigned symbols that are not valid for uplink transmission; Integrated circuits.

14. 1. An integrated circuit for controlling a process of a receiving device for receiving data from a transmitting device in a communication system, the process comprising: a process of allocating the data repetitions, including an initial transmission and one or more subsequent transmissions, and a demodulation reference signal (DMRS) to a time domain resource and obtaining a DMRS allocation indicating whether the DMRS is allocated to the time domain resource, the data repetitions each including a number of consecutive symbols less than a slot; a process for receiving the data and the DMRS from the transmitting device within the slot, the reception of the DMRS in the data repetition being performed according to the DMRS allocation; Including, symbols during the time domain resources are assigned symbols that are not valid for uplink transmission; Integrated circuits.

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