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

Abstract

To facilitate providing flexible demodulation reference signal configuration during repetition of a data channel.SOLUTION: A transmitting device according to an embodiment of the present disclosure includes a circuit that, during operation, allocates data repetitions and DMRS to time domain resources and obtains a DMRS allocation indicating whether a DMRS is allocated to the time domain resource, in which each of the data repetitions includes a number of consecutive symbols less than a slot, and a transceiver that, during operation, transmits the data and the DMRS to the receiving device within the slot, in which the transceiver performs transmission of the DMRS in the data repetitions on the basis of the DMRS allocation, and symbols between the data repetitions are assigned symbols that are not valid for uplink transmission.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present disclosure relates to transmission and reception, devices, and methods in a communication system such as a 3GPP (3rd Generation Partnership Project) (registered trademark) communication system.

Background Art

[0002] Recently, the 3rd Generation Partnership Project (3GPP) completed the first release (Release 15) of the technical specifications for the next-generation cellular technology, also known as the 5th generation (5G). At the Radio Access Network (RAN) meeting #71 of the 3GPP Technical Specification Group (TSG) (Gothenburg, March 2016), the first study item of 5G, "Study on New Radio Access Technology," in which RAN1, RAN2, RAN3, and RAN4 were involved, was approved as a potential work item for Release 15 that defines the first standard specifications of 5G. The purpose of the study item is to develop a "New (New) Radio (NR)" access technology defined during the RAN requirement study that operates in a frequency band up to 100 GHz and supports a wide range of use cases (see, for example, 3GPP TR 38.913 "Study on Scenarios and Requirements for Next Generation Access Technologies," the current version 14.3.0 available at www.3gpp.org).

[0003] The IMT-1010 (International Mobile Telecommunications-2020) specifications by the International Telecommunication Union broadly classify 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, the deployment scenarios for eMBB can include indoor hotspots, dense urban areas, suburbs, urban areas, and highways. The deployment scenarios for URLLC can include industrial control systems, mobile health management (remote monitoring, diagnosis, and treatment), real-time vehicle control, and wide-area monitoring and control systems for smart grids. mMTC can include scenarios that use a large number of devices for data transmission with little impact of latency, such as smart wearables and sensor networks.

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

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

Summary of the Invention

[0006] One non-limiting and exemplary embodiment facilitates providing a flexible demodulation reference signal configuration during repetition of a data channel.

[0007] In a general aspect, the technology disclosed herein features a transmitting device that transmits data to a receiving device in a communication system. The transmitting device, during operation, allocates 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 allocates a demodulation reference signal (DMRS) to the initial TTI. For each of the one or more subsequent TTIs, the transmitting device comprises circuitry to obtain a DMRS allocation indicating whether the DMRS is allocated to the subsequent TTI such that the DMRS is transmitted in addition to the 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 the same. The transmitting device further comprises a transceiver that, during operation, transmits to the receiving device the data and the DMRS allocated to the initial TTI and the data allocated to the one or more subsequent TTIs within a slot. The DMRS transmission in the one or more subsequent TTIs is performed according to the DMRS allocation.

[0008] Note that a general embodiment or a specific embodiment can be realized as a system, a method, an integrated circuit, a computer program, a storage medium, or any optional combination thereof.

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

Brief Description of the Drawings

[0010]

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DETAILED DESCRIPTION OF THE INVENTION

[0011] As presented in the Background section, 3GPP is working on the next release of the 5th generation cellular technology, simply referred to as 5G, which includes the development of new radio (NR) access technology operating in the frequency range up to 100 GHz. 3GPP has to identify and develop the technical components required to successfully standardize an NR system that timely meets both urgent market needs and more long-term requirements. To achieve this, the evolution of radio interfaces and radio network architectures is considered in the study item "New Radio Access Technology". The results and agreements are collected in the technical report TR 38.804 v14.0.0, which is incorporated herein by reference in its entirety.

[0012] In particular, there are provisional agreements regarding the overall system architecture. The NG-RAN (Next Generation - Radio Access Network) includes gNBs, which provide the NG-radio access user plane, SDAP / PDCP / RLC / MAC / PHY (Service Data Adaptation Protocol / Packet Data Convergence Protocol / Radio Link Control / Media Access Control / Physical), and the control plane, the RRC (Radio Resource Control) protocol termination towards the UE. The NG-RAN architecture is shown in Figure 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 executing the AMF) by the NG-C interface, and to the UPF (User Plane Function) (e.g., a specific core entity executing 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 non - centralized deployment scenario (section 5.2 of TR 38.801; centralized deployment is shown in section 5.4; this is incorporated herein by reference) is presented there, where a base station supporting 5G NR can be deployed. Figure 2 shows an exemplary non - centralized deployment scenario, additionally showing a user equipment (UE) connected to both a gNB and an LTE eNB and the LTE eNB, while being based on Figure 5.2.-1 of the aforementioned TR 38.801. As mentioned above, the new eNB for 5G NR may be exemplarily referred to as a gNB.

[0014] Also, as described above, in the 3rd Generation Partnership Project New Radio (3GPP NR), three use cases are considered that are expected to support a wide variety of services and applications by 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). The specifications for phase 1 of enhanced mobile broadband (eMBB) were finalized by 3GPP in December 2017. In addition to further expanding eMBB support, current and future work will involve standardization for ultra - reliable and low - latency communication (URLLC) and massive machine - type communication. Figure 3 (from Recommendation ITU - R M.2083) shows some examples of the expected usage scenarios of IMT after 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, and transportation safety. 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, the key requirements include a target user plane latency of 0.5 ms for UL (uplink) and 0.5 ms for DL (downlink). The general URLLC requirements for a single packet transmission are a BLER (Block Error Rate) of 1E-5 for a packet size of 32 bytes in a 1 ms user plane. From the perspective of RAN1, reliability can be improved in multiple possible ways. The current scope for improving reliability is incorporated into RP-172817, which includes the definition of separate CQI tables for URLLC, more compact DCI formats, PDCCH repetition, etc. However, as NR develops more stably, the scope may widen to achieve ultra-high reliability (see also 3GPP TR 38.9, which is incorporated herein by reference). Therefore, NR URLLC in Release 15 needs to be able to transmit 32-byte data packets within a user plane latency of 1 ms with a success rate corresponding to a BLER of 1E-5. Specific use cases of NR URLLC in Rel.15 include extended reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications (see also ITU-R M.2083-0).

[0017] Furthermore, the technical enhancements targeted by NR URLLC in Release 15 aim at improving latency and reliability. Technical enhancements for latency 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 are already allocated is stopped, and the already allocated resources are used for another transmission that is later requested but has lower latency requirements / higher priority requirements. Thus, an already permitted transmission is preempted by a later transmission. Preemption is applicable regardless of the specific service type. For example, a transmission for service type A (URLLC) can be preempted by a transmission for service type B (e.g., eMBB). Technical enhancements for reliability improvement include a dedicated CQI / MCS table for a target BLER of 1E-5 (for such technical 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, which are hereby incorporated by reference in their entirety).

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

[0019] As described above, it is expected that the scope of reliability in NR will become wider. One key requirement for all cases particularly necessary for URLLC and mMTC is high reliability or ultra-high reliability. To improve reliability from the perspectives of radio and network, several mechanisms can be considered. There are only a few key areas that can potentially help improve reliability. Among these areas are compact control channel information, data / control channel repetition, and diversity regarding the frequency domain, time domain, and / or spatial domain. These areas are generally applicable to reliability regardless of the specific communication scenario.

[0020] For NR URLLC Rel.16, further use cases with more stringent requirements, such as factory automation, transportation industry, and power distribution, have been identified (see RP-181477 "New SID on Physical Layer Enhancements for NR URLLC", Huawei, HiSilicon, Nokia, Nokia Shanghai Bell, which is incorporated herein by reference). These more stringent requirements are higher reliability (up to 10 -6 levels), higher availability, packet sizes up to 256 bytes, time synchronization on the order of several μs (the value can be 1 μs or several μs depending on the frequency range), and short latency on the order of 0.5 - 1 ms (especially the target user plane latency of 0.5 ms) according to the use case (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 technical extensions from the perspective of RAN1 have been identified. Among these are compact DCI, PDCCH (Physical Downlink Control Channel) repetition, and PDCCH extensions related to increased PDCCH monitoring. Furthermore, UCI (Uplink Control Information) extensions are related to extended HARQ (Hybrid Automatic Repeat Request) and CSI feedback extensions. Also, PUSCH extensions and retransmission / repetition extensions related to mini-slot level hopping have been identified. The term "mini-slot" refers to a Transmission Time Interval (TTI) that contains a smaller number of symbols than a slot (a slot containing 14 symbols).

[0022] Generally, the TTI defines the timing granularity for scheduling allocations. 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 transmissions and uplink transmissions are specified to be organized into frames (10 ms duration) consisting of 10 subframes (1 ms duration). In slot-based transmission, a subframe is divided into slots. The number of slots is defined by the numerology / subcarrier spacing, and the specified values are in the range between 10 slots for a 15 kHz subcarrier spacing and 320 slots for a 240 kHz subcarrier spacing. The number of OFDM symbols per slot is 14 for a normal cyclic prefix and 12 for an 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 transmission may also be non-slot-based. In particular, the TTI in non-slot-based allocation may correspond to a mini-slot instead of a slot. That is, one or more mini-slots may be allocated for the required transmission of data / control signaling. In non-slot-based allocation, the minimum length of the TTI can conventionally be 2 OFDM symbols.

[0023] Other specified enhancements are related to the scheduling / HARQ / CSI processing timeline and UL UE - to - Tx prioritization / multiplexing. Exemplary methods such as improved configured grant operation for UL configured grant (grant - free) transmission, explicit HARQ - ACK, ensuring K - fold repetition and mini - slot 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 is related to potential layer 1 enhancements for further improving reliability / delay and also for other requirements related to use cases specified in (RP - 181477 “New SID on Physical Layer Enhancements for NR URLLC”, Huawei, HiSilicon, Nokia, Nokia Shanghai Bell). Specifically, enhancements regarding PUSCH (Physical Uplink Shared Channel) repetition are discussed. The impact of the proposed ideas in this disclosure is expected to be on PUSCH repetition enhancements that are within the main scope of the new SI (Study Item) / WI (Work Item) for NR URLLC in Rel.16.

[0025] (PUSCH repetition) One of the scopes for potential enhancements is related to mini - slot repetition of PUSCH within a slot. The motivation for supporting PUSCH repetition within a slot is provided below, which can enable potential enhancements to the repetition mechanism to further improve reliability and / or delay to meet the new requirements of NR URLLC.

[0026] To achieve the latency requirement for URLLC PUSCH transmission, if the reliability requirement is met, one-shot transmission (i.e., single (TTI) allocation) is ideal. 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, when one-shot transmission is not sufficient, both retransmission and repetition are supported to achieve the target BLER. In HARQ-based retransmission, it is well known that the overall reliability is improved by using feedback information and improving subsequent retransmissions according to the channel state. However, retransmission incurs additional latency due to the feedback processing timeline. Therefore, repetition is useful for latency-tolerant services as it performs subsequent transmissions of the same data packet without waiting for feedback.

[0027] PUSCH repetition can be defined as "transmitting the same uplink data packet multiple times without waiting for the feedback of one or more previous transmissions of the same data packet". The advantage of PUSCH repetition is that, since feedback is not required, the overall reliability is improved and the latency is reduced compared to HARQ. However, generally, link adaptation may not be possible and resource usage may be inefficient.

[0028] In NR Rel.15, limited support for repetition is introduced. Only 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 in the case of slot-to-slot repetition. Such a type of repetition is mainly useful for PUSCH mapping type A which allows PUSCH transmission to start only from the beginning of the slot. Such limited support may not be able to achieve the more stringent delay requirement in NR Rel.15, i.e., a maximum delay of 0.5 ms. Therefore, in-slot PUSCH repetition is being considered for NR URLLC in Rel.16.

[0029] Repetition within the same slot can be supported for PUSCH mapping type B which allows scheduling of a given transmission (or repetition from any symbol of the slot as opposed to only the beginning of the slot in PUSCH mapping type A). For example, two repetitions can be scheduled adjacent within the slot as shown in Figure 5. This results in a lower delay between repetitions compared to slot-to-slot repetition. In this figure, a single transmission consists of 1 DMRS symbol and 3 data symbols, followed by exactly the same repetition.

[0030] However, it can be shown that the same configuration can be achieved even by a single transmission without repetition. Basically, the length of the initial transmission is longer and additional DMRS symbols are configured. This is supported in NR Rel.15 and as shown in Figure 6, additional DMRS is allocated to the 5th symbol of the slot. In the example shown in Figure 6, a single transmission consists of 1 front-end DMRS + 1 additional DMRS configuration and 6 data symbols which are substantially the same as in the case of repetition.

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

[0032] Therefore, in order to realize additional flexibility and advantages that cannot be achieved by a single allocation, it is desirable to improve mini-slot repetition within a slot. Thus, for PUSCH mapping type B, according to the proposal of the present disclosure, PUSCH repetition within the same slot should be supported only when an additional function with additional flexibility and advantages is realized compared to existing support for PUSCH transmission.

[0033] Such repetition within a slot seems to provide a function similar to a single allocation. However, when this is combined with other existing physical layer technologies, additional flexibility can be realized along with better advantages. Some possible use cases that can be realized only when slot repetition is supported are described below.

[0034] For PUSCH mapping type B, when frequency hopping between repetitions is allowed within a slot, the frequency diversity gain can be further utilized. This gives the flexibility to schedule each repetition over two or more hops depending on the size of the bandwidth part, as shown in Figure 7. Basically, more settings 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 a resource block in the frequency domain). However, frequency hopping can also refer to bandwidth part hopping. According to section 4.4.5 of TS 38.211 V15.0.0 (2017-12), a bandwidth part (or carrier bandwidth part) is a set of consecutive physical resource blocks defined in section 4.4.4.3, selected from a subset of consecutive common resource blocks defined in section 4.4.4.2 for a given numerology on a given carrier.

[0035] Another advantage of using repetitions within a slot is that, as shown in Figure 8, each repetition can be transmitted with a different beam in order to achieve an additional spatial diversity gain that is not possible in the case of a single transmission. Beamforming enables the energy of a given wireless transmission to be concentrated in a certain direction, and as a result, for example, the range can be extended 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] For a configured grant (also known as grant-free) PUSCH, all allocable resources for the PUSCH may or may not belong to the uplink. Only symbols indicated as UL can be used. Thus, it may happen that the number of symbols indicated as UL is not sufficient or not continuous to enable transmission of a longer PUSCH. Therefore, as shown in FIG. 9, a shorter PUSCH can be scheduled more efficiently, and the repetition of that PUSCH within a slot can utilize the non-continuous symbols available in the uplink.

[0037] For PUSCH mapping type B, it is the finding of the present disclosure that the repetition within a slot (i.e., the whole 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 utilizing frequency diversity and spatial diversity respectively. Further, for PUSCH mapping type B with a configured grant, it is recognized that the repetition within a slot enables efficient use of measurement resources with a small number of UL symbols.

[0038] In the conventional repetition, the same transport block (TB) is transmitted in the initial transmission, and all repetitions round with the same DMRS configuration. However, this may result in an optimal lower bound in terms of DMRS overhead. For example, as shown in FIG. 10, for a 2-symbol PUSCH with an initial transmission and 6 repetitions, the DMRS overhead is 50%, which is very high. For each repetition round, the mini-slot consists of 1 data symbol and 1 DMRS symbol within the corresponding TTI, which is very inefficient in terms of resource usage. This is because the DMRS symbols are very frequent over the slot period during which all the initial transmission and repetitions are performed.

[0039] Thus, it is recognized that the conventional repetition may result in a very large DMRS overhead in a specific scenario where the PUSCH length is very short. In other words, each repetition round corresponding to one subsequent TTI / minislot among subsequent TTIs / minislots consists of 1 data symbol and 1 DMRS symbol, which is very inefficient in terms of resource utilization. This is because the DMRS symbols are very frequent over the slot period. Therefore, it is desirable to improve the minislot repetition within a slot in order to improve the latency and / or reliability as compared to the conventional repetition mechanism.

[0040] On the other hand, for a high-mobility UE (i.e., a UE that moves at a high speed and thus requires 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 enable changing or varying the DMRS allocation / DMRS symbol allocation in at least one of the repetitions set by a signaling mechanism in the minislot repetition of data within a slot. For this purpose, the proposed transmitting device, receiving device, transmitting method, and receiving method are described in the following aspects and embodiments of the present disclosure.

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

[0043] Generally, the present disclosure provides a transmitting device 1110 that transmits data to a receiving device 1160 via 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. During 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 the same. In addition to the data, a demodulation reference signal (DMRS) is allocated to an initial TTI among the plurality of TTIs. Further, during operation, the circuit 1130 obtains a DMRS allocation indicating whether the DMRS is allocated to each subsequent TTI of the subsequent TTIs following the initial TTI among the plurality of TTIs. In the present disclosure, a device or device component adapted or configured to perform a given task is referred to as "during operation" and performs the given task. According to the described operation, the processing circuit 1130 includes a DMRS allocation acquisition unit 1231 and a DMRS / data allocation unit 1232 as shown in FIG. 12. The DMRS allocation acquisition unit 1231 obtains the DMRS allocation during operation. The DMRS / data allocation unit allocates data to the plurality of TTIs, allocates the DMRS to the initial TTI, and allocates or does not allocate the DMRS to the subsequent TTIs according to the DMRS allocation obtained by the DMRS allocation acquisition unit 1231.

[0044] The DMRS allocation is an allocation scheme or allocation setting indicating whether the DMRS is allocated to this TTI for the TTI. That is, the DMRS allocation indicates whether the DMRS is allocated to be transmitted in the TTI in addition to the data. Therefore, for one of the subsequent TTIs among the subsequent TTIs, if the DMRS allocation indicates that the DMRS should be transmitted in this subsequent TTI, the DMRS is allocated to this subsequent TTI. However, if the DMRS allocation indicates that the 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., the hardware components and software components of the transmitting device and / or receiving device adapted to transmit / receive radio signals and modulate / demodulate data assigned to the time resources and frequency resources of the radio signals, which means the transmitter and receiver) transmits, during operation, within a slot, data assigned to a plurality of TTIs to the receiving device. Further, the transceiver 1120 transmits, at an initial TTI, the DMRS assigned to the initial TTI and executes DMRS transmission at one or more subsequent TTIs according to the obtained DMRS assignment. That is, on the one hand, at a subsequent TTI to which DMRS is assigned, DMRS and data are transmitted. On the other hand, at a subsequent TTI to which DMRS is not assigned, DMRS is not transmitted and data is transmitted.

[0046] The present disclosure further provides a receiving device 1160 that receives data from a transmitting device 1110 via a channel (e.g., a radio channel) in a communication system such as a radio system. The receiving device 1160 includes a circuit 1180 and a transceiver 1170. The circuit 1180 of the receiving device obtains, during operation, a DMRS assignment for each of one or more subsequent TTIs, i.e., each of the subsequent TTIs following the initial TTI. The plurality of TTIs including the initial TTI and the subsequent TTIs each have a number of symbols less than that of a slot. The data assigned to each of the plurality of TTIs is the same. According to the above description, the DMRS assignment for a TTI indicates whether DMRS is assigned to this TTI so that DMRS is received in addition to the data. The transceiver 1170 of the receiving device 1160 receives, during operation, from the transmitting device, within a slot, the data and DMRS assigned to the initial TTI and the data assigned to one or more subsequent TTIs. The DMRS reception at one or more subsequent TTIs is executed according to the DMRS assignment.

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

[0048] As described above, data and in some cases reference signals are each allocated to a transmission time interval (TTI) smaller than a slot. Thus, the present disclosure is particularly related to the non-slot-based allocation described above. As described above, in non-slot-based allocation, the minimum length of the TTI can conventionally be 2 OFDM symbols. Such a 2-symbol TTI is shown in FIG. 10. A TTI smaller than a slot is called a mini-slot in the present disclosure. However, this does not limit the present disclosure to such terms. In particular, due to the small size of the mini-slot TTI, the entire series of repetitions including the initial transmission in the first 2 symbols (i.e., 1 DMRS symbol and 1 data symbol) and 6 repetitions each including 1 DMRS symbol and 1 data symbol fit within a slot, and thus the entire series of repetitions is made within a single slot. Further, the present disclosure also accommodates a TTI to which DMRS is not allocated, i.e., a TTI that does not include a DMRS symbol. Thus, when the DMRS symbol is removed from a mini-slot having only 1 data symbol, the minimum size of the TTI becomes 1 symbol instead of the conventionally assumed 2 symbols.

[0049] Within a TTI / mini-slot to which DMRS is allocated, the (DMRS) symbol to which DMRS is allocated precedes one or more symbols in which data is transmitted. The DMRS is used at the receiver side for channel estimation for coherent demodulation. In general, the TTI can also include a plurality of DMRS symbols for DMRS retransmission that precede one or more data symbols in which data is transmitted.

[0050] However, in a scenario where the channel characteristics are not expected to change during the duration of one or two minislots in a way that coherent demodulation is impaired, it may be sufficient to allocate DMRS symbols to the first TTI before one or more subsequent TTIs, but not allocate DMRS to one or more subsequent TTIs. That is, in such a case, DMRS is not transmitted in at least one of the one or more subsequent TTIs / minislots following the initial TTI. Not allocating DMRS to subsequent TTIs within a slot can be done, for example, in use cases where the transmitting device is expected to be stationary or moving at a low speed, such as factory automation.

[0051] An example of flexible DMRS allocation for data repetition is shown in FIG. 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 2 symbols, followed by 6 data repetitions in 6 subsequent TTIs. In the first repetition and the fourth repetition, additional DMRS is transmitted, that is, both the first subsequent minislot and the fourth subsequent minislot contain DMRS symbols in addition to data symbols. Therefore, the DMRS allocations for the first subsequent TTI and the fourth subsequent TTI each indicate that DMRS is transmitted in these TTIs. On the other hand, according to the respective DMRS allocations for a plurality of TTIs corresponding to the second repetition, the third repetition, the fifth repetition, and the sixth repetition, DMRS is not allocated to any of these TTIs.

[0052] The advantages of the transmission / reception device and the transmission / reception method of the present disclosure are that flexible removal and / or replacement of DMRS in one or more data repetitions as described below, and flexible allocation and non-allocation of DMRS to minislots can enable settings with further advantages that are not possible with a single allocation (i.e., the same DMRS allocation for each TTI of the repetition) due to the limited existing DMRS settings.

[0053] As described above, the DMRS allocation scheme for a minislot (i.e., a TTI having fewer symbols than a slot) indicates or specifies whether DMRS is allocated to the minislot, specifically, to one or more symbols of the minislot (generally including the first symbol in chronological order). Therefore, the DMRS allocation is also referred to as DMRS symbol allocation in the present disclosure. Further details regarding possible DMRS symbol allocations are provided below. In particular, when the DMRS symbol allocation for at least one TTI within a slot specifies that DMRS is not allocated to that TTI, how the data is allocated to each symbol of the TTI within the slot is described.

[0054] So far, in a series of DMRS repetitions in a minislot within one slot, it has been described that DMRS is not allocated to the specific TTI in which the data repetition is performed. In particular, flexible DMRS allocation or DMRS symbol allocation changes according to some embodiments of the present disclosure can mean the following: - 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. Flexible removal of one or more DMRS symbols in one or more repetitions can facilitate reducing the delay to achieve the final target BLER compared to conventional repetitions (i.e., repetitions in which DMRS is allocated to each TTI in which the repetition is performed). - In one or more DMRS symbols in a given repetition, they are replaced by one or more data symbols, and the transport block (TB) corresponding to the data to be transmitted is transmitted at a reduced coding rate for the initial transmission. The flexible replacement of one or more DMRS symbols in one or more repetitions can facilitate an increase in reliability as compared to conventional repetitions. - The removal and replacement of one or more DMRS symbols are combined. This can easily provide improvements in both latency and reliability as compared to conventional repetitions.

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

[0056] Thus, one possible extension to conventional repetitions is to enable the flexibility to remove DMRS from a specific repetition according to the channel state and reliability requirements. As an example, in the case of a 2-symbol PUSCH with an initial transmission and 6 repetitions, if it is allowed to remove DMRS from a specific repetition, one possibility would appear like the above-described allocation of data and DMRS to the TTI shown in FIG. 14. This flexibility not only enables control of the DMRS overhead but also provides further flexibility in terms of DMRS settings that are not currently supported in NR Rel. 15. Furthermore, by enabling such flexibility, the overall latency is also reduced.

[0057] For a mini-slot / TTI without DMRS symbols, the repetition round without DMRS corresponding thereto uses the last available DMRS for channel estimation. In particular, the second and third repetitions are without DMRS, and these use the DMRS from the first repetition for demodulation. Similarly, the fifth and sixth repetitions are without DMRS, and these use the DMRS from the fourth repetition for demodulation.

[0058] Regarding demodulation performance, in particular, in applications having low mobility requirements for a transmitting device such as a UE, there should be a negligible difference for repetitions without DMRS. This is because the interval from the last available DMRS from the previous repetition is still rather small. Further, in each repetition round of the initial data transmission and the repetition rounds, the same MCS (modulation and coding scheme), in particular the same coding rate, may be used. This is because, for example, the same amount of data symbols, such as one data symbol per transmission, is available in each subsequent TTI of the initial TTI and one or more subsequent TTIs.

[0059] Such a setting (in particular, data / DMRS allocation to symbols within one slot) is not possible according to the currently supported DMRS settings for a single allocation. For such a setting, the performance may be similar or may be improved compared to the current settings for a single transmission.

[0060] Furthermore, compared to the conventional repetitions, the same reliability can be obtained while reducing the delay. For example, as shown in FIG. 14, the delay is reduced by four symbols.

[0061] Furthermore, resources (especially time-domain resources) can be saved for conventional repetitions. In conventional repetitions, all 14 symbols of a slot are used for a series of initial transmissions and 6 repetitions. However, according to this embodiment, some symbols within a slot (e.g., the last 4 symbols of the slot shown in FIG. 14) cannot be used for a series of initial transmissions and repetitions and may be used for other transmissions, such as other URLLC traffic in the queue for the same or other UEs.

[0062] Therefore, particularly with respect to the above-described PUSCH mapping type B, it is a further finding of the present disclosure that removing DMRS from a particular repetition round in the repetition within a slot for PUSCH mapping type B can reduce the DMRS overhead and provide further flexibility in DMRS configuration, which is not currently possible in NR Rel. 15. An additional finding is that removing DMRS from a particular repetition round in the repetition within a slot for PUSCH mapping type B can also reduce the overall latency and make resources available for other traffic in the pipeline, such as URLLC / eMBB.

[0063] (Replacement of DMRS) According to some embodiments, for the DMRS allocation for a subsequent TTI among one or more subsequent TTIs, it is further indicated that if the DMRS is not allocated to this subsequent TTI, which is smaller than a slot, the symbols for the DMRS allocation in this subsequent TTI are replaced by the symbols for the data allocation. In other words, in a mini-slot, the DMRS symbols are replaced by data symbols.

[0064] An exemplary allocation of DMRS and data to symbols of a TTI within a slot, where the DMRS symbol is replaced by a data symbol, is shown in FIG. 15. This slot contains seven mini-slots, each mini-slot containing two symbols. The first (initial) mini-slot in which an initial PUSCH transmission is performed, and subsequent TTIs to which data is allocated for the first repetition, the third repetition, and the fifth repetition, each contain 1 DMRS symbol and 1 data symbol. However, the second repetition, the fourth repetition, and the sixth repetition each have no data symbol. In the TTIs corresponding to these repetitions, the DMRS is replaced by a data symbol respectively. Thus, each of the second subsequent mini-slot, the fourth subsequent mini-slot, and the sixth subsequent mini-slot contains 2 data symbols instead of 1 DMRS symbol followed by 1 data symbol.

[0065] The principle for maintaining the desired demodulation performance can be applied by reducing the MCS (i.e., coding rate) in a specific repetition by the DMRS allocation scheme for repetitions within a slot to improve the coding gain and making sure that the interval between the data symbol and the DMRS does not become too long. As can be seen from FIG. 15, in a TTI having two symbols, when the DMRS symbol is replaced by a data symbol, the number of symbols available for transmission doubles. Further, the same data is transmitted in each repetition. Thus, in the example of two symbols, the coding rate can be basically reduced to half of the coding rate of the initial data transmission in all repetitions to which the change (i.e., replacement of the DMRS symbol with a data symbol) is applied. However, since the present disclosure is not limited to TTIs having two symbols, the reduced coding rate can also take a value other than half of the original coding rate at which the data is coded in the initial TTI and the subsequent TTIs including the DMRS symbol.

[0066] For a configuration where DMRS symbols are replaced with data symbols, as illustrated in FIG. 15, better or similar performance can be achieved compared to a single allocation that is not possible according to the current DMRS configuration. Further, reliability can be further improved while maintaining the same latency compared to conventional repetition.

[0067] As described above, DMRS symbols may be removed from or replaced in a specific TTI within a slot. For example, within a single slot or a series of slots, changes to the DMRS symbol allocation may be limited to either removal or replacement of the DMRS symbol. That is, within such a slot, if DMRS is not allocated to one or more subsequent TTIs, only removal or only replacement is performed. However, as will be described in the following embodiments, removal and replacement of DMRS symbols 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 either that when DMRS is not allocated to a TTI, the length of this TTI is reduced by one symbol corresponding to DMRS (removal of the DMRS symbol), or that the symbol for the allocation of DMRS in this TTI is replaced with a symbol for the allocation of data (replacement of the DMRS symbol). Thus, within one or more subsequent TTIs in which data is repeatedly transmitted within a slot, a configuration is possible where DMRS symbol removal is applied to one of the subsequent TTIs and DMRS symbol replacement is applied to another 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 the transmission order, or vice versa.

[0069] Slots in which both the removal and replacement of DMRS symbols are performed at different TTIs included in a slot are shown in FIG. 16. Specifically, the second and fifth subsequent minislots in which the second and fifth repetitions are performed have no DMRS symbols, and the lengths of these minislots are reduced accordingly. The third and sixth subsequent minislots corresponding to the third and sixth repetitions are also similarly without DMRS symbols, and in these minislots, the DMRS symbols are replaced with further data symbols. In the third and sixth repetitions each including two data symbols, as described above, the coding rate can be reduced by half. Further, as can be seen more clearly from this figure, the last two symbols of the slot in chronological order are not used for a series of initial transmissions and repetitions, and thus are available for other traffic in the pipeline.

[0070] Such a mixed use of DMRS symbol removal and DMRS symbol replacement with data symbols facilitates an increase in reliability and can reduce the delay with respect to conventional repetitions. DMRS symbol removal can provide delay improvement, while DMRS symbol replacement with coding rate reduction can facilitate an increase in reliability, but the combination of these embodiments provides better flexibility and allows a trade-off between different objectives.

[0071] As described above, in some embodiments, when the symbol for DMRS allocation in a TTI is replaced by a symbol for data allocation, the data is transmitted in this TTI at a code rate lower than the code rate (or coding rate) at which the data is transmitted in the initial TTI. For example, as shown, the lower code rate may be half of the code rate at which the data transmitted in the initial TTI / minislot is coded, but the present disclosure is not limited to reducing the coding rate to 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 symbol, the coding rate can be reduced to two-thirds of the coding rate used in the initial transmission. As described above, the aforementioned reduction in the coding rate should be understood as being 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 the coding rate is independent of the original value of the coding rate.

[0072] (Uplink Transmission and Repetition) Examples of a series of initial transmissions and repetitions that constitute uplink transmissions such as PUSCH (Physical Uplink Shared Channel) transmissions have been shown. Thus, in some embodiments, the transmitting device 1110 (specifically, the transceiver 1120 during operation of the transmitting device 1110) transmits data to the receiving device over the uplink, and the transceiver 1120 of the transmitting device 1110 further receives control signaling from the receiving device 1160. Correspondingly, the receiving device 1160 transmits control signaling to the transmitting device.

[0073] The control signaling includes an allocation indicator indicating each DMRS allocation for each subsequent TTI of the subsequent TTIs. The circuit 1130 of the transmitting device obtains the DMRS allocation for each TTI of the TTIs following the initial TTI by evaluating the control signaling.

[0074] In an embodiment where the transmitting device 1110 transmits data to the receiving device 1160 on the uplink, the transmitting device may be a terminal or a user equipment, and the receiving device 1160 may be a base station called a gNB or gNodeB in an NR (New Radio) communication system corresponding to an eNodeB (eNB) of an 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] The uplink transmission method and uplink reception method according to the present disclosure are shown in FIG. 17. As shown in the figure, the gNB corresponding to the receiving device 1160 obtains DMRS through a determination step S1760 (implementing step S1360 in FIG. 13) for determining the DMRS allocation. Specifically, such a determination of the DMRS allocation is performed based on channel quality estimation. Specifically, the base station can estimate the channel quality based on the uplink sounding reference signal (SRS) transmitted by the UE for the purpose of channel quality estimation. The gNB can receive SRS from one or more UEs and determine the DMRS allocation based on the channel state corresponding to the channel quality estimated based on the received SRS.

[0076] Next, the gNB / base station generates a DMRS allocation indicator and transmits, in step S1765, control signaling including the DMRS allocation indicator to the (user) terminal. The user terminal receives, in step S1710 (implementing step S1310 in FIG. 13), the control signaling including the DMRS allocation indicator, thereby obtaining the DMRS allocation. The allocation 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 methods shown in FIG. 13.

[0077] (Control Signaling) Specifically, in some embodiments, for each of one or more subsequent TTIs, the DMRS allocation indicator is a 2-bit allocation indicator. The 2 bits are sufficient to indicate whether the DMRS is allocated to the TTI and further indicate which option of either DMRS removal or DMRS replacement applies. Thus, each repetition can be associated with one of the following 2-bit indications respectively. - "00": There is no change to one or more DMRS symbols in a given repetition (i.e., the DMRS is allocated to the TTI) - "01": One or more DMRS symbols are removed and the TTI length of the given repetition is reduced - "10": One or more DMRS symbols are replaced with one or more data symbols and the coding rate of the given repetition is reduced - "11": Reserved entry

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

[0079] Obviously, the association between the 2-bit value and the DMRS allocation is merely illustrative. Alternatively, for example, "10" may represent DMRS symbol removal.

[0080] Alternatively, the DMRS allocation indicator may have more or fewer bits than 2 bits. Specifically, for each subsequent TTI of the subsequent TTIs transmitted within a slot, the DMRS allocation indicator may be a 1-bit indicator, and as a result, for the indication of DMRS allocation for up to 6 retransmissions, it becomes a 6-bit field. For example, if it is clear or known from the standard or further control signaling what specific changes are made to the allocation in the TTI (e.g., whether the removal or replacement of the DMRS symbol is performed), the 1-bit indicator corresponding to the TTI is sufficient to indicate whether the DMRS is allocated to this TTI. For example, the bit value of "0" can indicate that the DMRS is allocated to and transmitted in this TTI, and the bit value of "1" can indicate that the DMRS is not allocated, regardless of whether the DMRS symbol is replaced or removed. Therefore, the 6-bit DMRS allocation indicator obtained as a result for all 6 repetitions is "011011" in the example (removal) shown in FIG. 14 and "010101" in the example (replacement) shown in FIG. 15. Also in this case, the values of "0" and "1" may be reversed, and in this case, the value of "1" means the allocation of the DMRS to the TTI.

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

[0082] In some embodiments, the control signaling further includes a DMRS activation indicator indicating whether the DMRS is not allocated to any of one or more subsequent TTIs. Thus, the DMRS activation indicator, which may be a 1-bit indicator, can indicate whether a flexible repetition setting (in addition to whether the DMRS is allocated or not allocated to a subsequent TTI, the type when not allocated) is applied. In other words, the DMRS activation indicator is set to invalidate or activate a flexible DMRS setting. Further, the selection of a specific DMRS activation indicator can indicate the degree of flexibility in DMRS allocation.

[0083] Specifically, the DMRS activation indicator may be a 1-bit indicator indicating whether flexible DMRS is applied within a slot or within a longer time interval including several slots (for example, the activation indicator may be signaled quasi-statically as described later). For example, "0" indicates that a flexible repetition that allows the DMRS not to be allocated to a specific TTI is not applied, and "1" indicates that a flexible repetition is applied (or vice versa). The 1-bit activation indicator may be used in combination with each 2-bit indicator for a specific group of TTIs of the series of repetitions described above. For example, when the DMRS activation indicator indicates that flexible DMRS is applied, the 2-bit indicator can specify whether DMRS allocation, DMRS removal, or DMRS replacement is applied for a specific TTI within the slot.

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

[0085] The activation indicator may be included in the upper layer signaling. Alternatively, the activation indicator may be included in, for example, the downlink control information (DCI) that can be regarded as dynamic signaling for transmitting scheduling information (grant) and / or transmission parameters (i.e., the physical layer control signaling message transmitted on the PDCCH (physical downlink control channel)). The present disclosure is not limited to a specific DCI format, and the format may correspond to the existing / specified DCI format for NR, or may be agreed upon in the future for specific services such as URLLC. On the one hand, including the activation indicator in the DCI provides better flexibility because the activation / deactivation of DMRS allocation can be performed using the grant for a flexible series of data repetitions. On the other hand, signaling the activation indicator in the upper layer signaling instead of the DCI can avoid introducing additional DCI signaling and thus the DCI signaling overhead. However, advantageously, a 1-bit allocation indicator is used when the DMRS allocation indicator is included in the DCI.

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

[0087] When the DMRS allocation / activation setting is performed only by RRC signaling, a 2-bit field (referred to in the present disclosure as "bit field 1" and "bit field 2") can enable complete flexibility to remove or replace DMRS symbols in any repetition round of the repetition rounds (i.e., flexibly specify in what order removal, replacement, or allocation is respectively performed within a series of repetitions).

[0088] Bit field 1 may correspond to the above-described 1-bit activation indicator indicating whether a flexible repetition setting is applied. The exact repetition setting (DMRS allocation) can be set by bit field 2 corresponding to the 2-bit allocation indicator provided for each TTI. In bit field 2, the maximum number of bits is twice the maximum allowable number of repetitions. For example, if a maximum of 6 repetitions is allowed, a 12-bit field is defined in RRC to enable a flexible repetition setting. 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 FIG. 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 shown in FIG. 18 described above.

[0089] As an alternative to bit field 1, which is a 1-bit field, and bit field 2, which is a field up to a maximum of 12 bits, a 1-bit activation indicator indicating whether DMRS replacement or DMRS removal is applied may be combined with each 1-bit DMRS allocation indicator for the subsequent TTI described above. As a further alternative, a 2-bit activation indicator as described above may be combined with each 1-bit allocation indicator. In the latter signaling mechanism, bit field 2, which is up to a maximum of 12 bits, may be reduced by only half of the bits and reduced to a field up to a maximum of 6 bits. Therefore, resources in RRC signaling are saved.

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

[0091] As an alternative to the control signaling of DMRS allocation / activation only in RRC, the signaling mechanism may include both RRC signaling and DCI signaling. Such an embodiment may enable a certain degree of dynamism in DMRS allocation.

[0092] Specifically, a field called "bit field 1" may be transferred to the DCI. That is, a 1-bit field corresponding to one of the 1-bit activation indicators described above is added to the DCI to dynamically signal whether a flexible repetition setting (in this case, still configurable by the RRC bit field) is applied (when the flexible repetition setting is applied, the DCI bit field value is "1"; when the flexible repetition setting is not applied, the DCI bit field value is "0"). When the control signaling in the RRC and the control signaling in the DCI are combined, the RRC bit field in the RRC signaling may be the same as the "bit field 2" described above for exclusive use in the RRC. Therefore, the repetition setting pattern (i.e., the respective DMRS allocation for subsequent TTIs) is the same, but its application (i.e., the activation (deactivation) of "switching" the flexible DMRS allocation on or off) is dynamically performed via the DCI.

[0093] As described above, the 1-bit field in the DCI may be a 1-bit activation indicator that specifies the activation or deactivation of flexible DMRS allocation. In this case, the bit field in the RRC signaling may correspond to a 2-bit DMRS allocation indicator (up to 12 bits for up to 6 repetitions) as described above, which also indicates whether DMRS symbol replacement or DMRS symbol removal is applied. However, the 1-bit field in the DCI can also correspond to the above-described indicator that indicates whether DMRS removal or DMRS replacement is applied. In this case, the DMRS allocation indicator can have 1 bit for each subsequent TTI (up to 6 bits for up to 6 repetitions) as described above. As a further alternative, the type of symbol allocation (replacement or deletion) when DMRS is not allocated repeatedly may be predefined, for example, by the standard. In this case, a 1-bit activation indicator in the DCI and a 1-bit DMRS allocation indicator for each subsequent TTI (e.g., 6 bits corresponding to 6 repetitions) are sufficient.

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

[0095] Furthermore, it should be noted that the present disclosure aims to enable 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 the present disclosure can also be utilized in scenarios of frequency hopping, beam hopping, and small measurement resources, as shown in FIGS. 19 to 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 the data assigned to each subsequent TTI of one or more subsequent TTIs in a set of subcarriers different from the set of subcarriers in which the data was transmitted in the TTI immediately preceding the subsequent TTI among the plurality of TTIs. In other words, in two TTIs among the plurality of TTIs, the data is assigned to different sets of subcarriers and transmitted in different sets 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 part described above. Thus, frequency hopping can be performed before each subsequent TTI to which the DMRS is assigned. However, when the frequency hopping is performed from one TTI to the next among the plurality of TTIs, the data in the TTI after the frequency hopping step / operation is transmitted in the set of subcarriers in which the DMRS was transmitted in one TTI before the TTI after the hopping step among the plurality of TTIs. In FIG. 19, frequency hopping is performed between two respective frequency groups / sets.

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

[0099] The beam change or frequency change from one TTI to the next TTI may be signaled quasi-statically. For example, in addition to the DMRS allocation indicator, the RRC signaling may similarly include a beam hopping pattern indicator or a frequency hopping pattern indicator. Further, 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 plurality of TTIs to which data is allocated for transmission in the initial transmission and repetition are not consecutive. That is, between two TTIs of the plurality of TTIs, there are symbols that are not included in any of the plurality of TTIs. That is, other data and / or control signaling different from the data allocated to each TTI of the plurality of TTIs may be allocated to the symbols between two TTIs of the plurality of TTIs. An example is shown in FIG. 21. In FIG. 21, within a slot, there is an initial PUSCH transmission and three data repetitions, and the DMRS is allocated 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 series of initial transmissions and repetitions. Further, these symbols that exist in between are symbols not used for uplink transmission.

[0101] Further, in most of the examples shown, the initial transmission starts with a DMRS allocated to the first symbol of the slot. However, particularly in accordance with the above-described PUSCH mapping type B, the present disclosure is not limited to the initial TTI including the first symbol in the slot in chronological order. Alternatively, the initial transmission may start with a symbol other than the first symbol in the slot.

[0102] The present disclosure can be implemented by software, by hardware, or by software cooperating with hardware. Each functional block used in the description of each of the above-described embodiments can be implemented 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 part or all of the functional blocks. The LSI can include a data input / output section coupled to itself. Depending on the degree of integration, the LSI may be referred to as an IC, a system LSI, a super LSI, or an ultra LSI. However, the technology for implementing the integrated circuit is not limited to the LSI, and can be implemented by using an application specific circuit, a general-purpose processor, or a dedicated processor. Further, an FPGA (field programmable gate array) that can be programmed after the manufacture of the LSI, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells arranged inside the LSI can also be used. The present disclosure can be implemented as digital processing or analog processing. As a result of the progress of semiconductor technology or another derivative technology, if the LSI is replaced by future integrated circuit technology, the functional blocks can be integrated using the future integrated circuit technology. Biotechnology can also be applied.

[0103] According to one general aspect, the present disclosure provides a transmitting device that transmits data to a receiving device in a communication system. During operation, the transmitting device allocates the data to a plurality of transmission time intervals (TTIs) including an initial TTI and one or more subsequent TTIs following the initial TTI. Further, the transmitting device allocates a demodulation reference signal (DMRS) to the initial TTI, and for each of the one or more subsequent TTIs, obtains a DMRS allocation indicating whether the DMRS is allocated to the subsequent TTI such that the DMRS is transmitted in addition to the 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 the same. The transmitting device includes a circuit and a transceiver. The circuit is configured to perform the above operations, and the transceiver is configured to transmit, within the 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, and the DMRS transmission in the one or more subsequent TTIs is performed according to the DMRS allocation.

[0104] This provides better flexibility for repetition and facilitates delay reduction and / or reliability enhancement.

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

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

[0107] This facilitates reducing the delay.

[0108] In other embodiments, the DMRS allocation further indicates that when the DMRS is not allocated to the subsequent TTI, the symbol for allocating the DMRS in the subsequent TTI is replaced with the symbol for allocating the data.

[0109] This facilitates enhancing reliability.

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

[0111] This facilitates reducing latency and enhancing reliability.

[0112] For example, when the symbol for the DMRS allocation in the subsequent TTI is replaced by the symbol for the data allocation, the data is transmitted in the subsequent TTI at a coding rate lower than the coding 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 the uplink, and during operation, the transceiver further receives control signaling including a DMRS allocation indicator indicating the DMRS allocation for each of the one or more subsequent TTIs from the receiving device, and the circuit obtains the DMRS allocation for each of the one or more subsequent TTIs by evaluating the control signaling during operation.

[0114] For example, the DMRS allocation indicator for each subsequent TTI is a 2-bit allocation indicator.

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

[0116] For example, the control signaling further includes an activation indicator indicating whether the DMRS is not allocated to any of the one or more subsequent TTIs.

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

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

[0119] In other exemplary embodiments, the activation indicator is a 1-bit indicator included in the downlink control information (DCI).

[0120] This enables flexible dynamic switching of DMRS allocation.

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

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

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

[0124] In some embodiments, a symbol between two TTIs 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, during operation, obtaining a demodulation reference signal (DMRS) assignment indicating, for each of one or more subsequent TTIs following an initial transmission time interval (TTI), whether a 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 fewer 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, during operation, receiving 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 allocated in that subsequent TTI, the length of that subsequent TTI is reduced by one symbol corresponding to the DMRS.

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

[0130] For example, when the symbol for the allocation of the DMRS in the subsequent TTI is replaced with the symbol for the allocation of 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 from the transmitting device on the uplink, and further transmits control signaling including a DMRS allocation indicator indicating the DMRS allocation to the transmitting device for each of the one or more subsequent TTIs.

[0132] For example, the DMRS allocation indicator for each subsequent TTI is a 2-bit allocation indicator.

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

[0134] For example, the control signaling further includes an activation indicator indicating whether the DMRS is not allocated to any of the one or more subsequent TTIs.

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

[0136] In other exemplary embodiments, the activation indicator is a 1-bit indicator included in the downlink control information (DCI).

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

[0138] For example, in two of the plurality of TTIs, the data is allocated to respective different sets of subcarriers and is received in the respective different sets of subcarriers.

[0139] For example, in two of the plurality of TTIs, the data is received in respective 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 is a transmission method for a transmitting device that transmits data to a receiving device in a communication system. For each subsequent transmission time interval (TTI) following an initial TTI, obtaining a DMRS allocation indicating whether a demodulation reference signal (DMRS) is allocated to the subsequent TTI so as to be transmitted in addition to the data, wherein the plurality of TTIs including the initial TTI and the one or more subsequent TTIs each include a number of symbols less than a slot; allocating the same data to each TTI of the plurality of TTIs, and allocating DMRS to the initial TTI; and transmitting, within the 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, wherein DMRS transmission in the one or more subsequent TTIs is performed according to the DMRS allocation.

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

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

[0144] In other embodiments, the DMRS allocation further indicates that when the DMRS is not allocated to the subsequent TTI, the symbol for allocation of the DMRS in the subsequent TTI is replaced by the symbol for allocation of the data.

[0145] In further embodiments, the DMRS allocation further indicates either that when the DMRS is not allocated to the subsequent TTI, the length of the subsequent TTI is reduced by one symbol corresponding to the DMRS, or that the symbol for allocation of the DMRS in the subsequent TTI is replaced by the symbol for allocation of the data.

[0146] For example, when a symbol for allocation of the DMRS in the subsequent TTI is replaced with a symbol for allocation of 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 the uplink to the receiving device, and the transmission method further includes receiving, from the receiving device, control signaling including a DMRS allocation indicator indicating the DMRS allocation for each of the one or more subsequent TTIs, and in the step of obtaining, the DMRS allocation is obtained for each 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 2-bit allocation indicator.

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

[0150] For example, the control signaling further includes an activation indicator indicating whether the DMRS is not allocated to any of the one or more subsequent TTIs.

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

[0152] In other exemplary embodiments, the activation indicator is a 1-bit indicator included in downlink control information (DCI).

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

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

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

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

[0157] According to another general aspect, the present disclosure is a receiving method for a receiving device that receives data from a transmitting device in a communication system, and for each of one or more subsequent TTIs following an initial transmission time interval (TTI), obtaining a DMRS allocation indicating whether a demodulation reference signal (DMRS) is allocated to the subsequent TTI so as to be received in addition to the data, wherein the plurality of TTIs including the initial TTI and the one or more subsequent TTIs each include a number of symbols less than a slot, the DMRS is allocated to the initial TTI, and the data allocated to each TTI of the plurality of TTIs is the same; and receiving, from the transmitting device, in the slot, the data allocated to the initial TTI and the DMRS and the data allocated to the one or more subsequent TTIs, wherein the DMRS reception in the one or more subsequent TTIs is performed according to the DMRS allocation.

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

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

[0160] In other embodiments, the DMRS allocation further indicates that when the DMRS is not allocated to the subsequent TTI, the symbol for the allocation of the DMRS in the subsequent TTI is replaced with the symbol for the allocation of the data.

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

[0162] For example, when the symbol for the allocation of the DMRS in the subsequent TTI is replaced with the symbol for the allocation of the data, the data is transmitted in the subsequent TTI at a coding rate lower than the coding rate at which the data is transmitted in the initial TTI.

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

[0164] For example, the DMRS allocation indicator for each subsequent TTI is a 2-bit allocation indicator.

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

[0166] For example, the control signaling further includes an activation indicator indicating whether the DMRS is not allocated to any of the one or more subsequent TTIs.

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

[0168] In other exemplary embodiments, the activation indicator is a 1-bit indicator included in downlink control information (DCI).

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

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

[0172] In some embodiments, a certain symbol between two TTIs 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 that transmits data to a receiving device in a communication system. During operation, the transmitting device allocates 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 allocates a demodulation reference signal (DMRS) to the initial TTI. For each of the one or more subsequent TTIs, the transmitting device includes a circuit that obtains a DMRS allocation indicating whether the DMRS is allocated to the subsequent TTI such that the DMRS is transmitted in addition to the 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 the same. During operation, the transmitting device further includes a transceiver that transmits the data and transmits the DMRS according to the DMRS allocation within the slot.

Claims

1. A circuit that, during operation, allocates repeated data and a demodulation reference signal (DMRS) to time-domain resources and obtains a DMRS allocation indicating whether the DMRS is allocated to the time-domain resources, wherein each repetition of the data includes a number of consecutive symbols less than a slot, and a circuit; A transceiver that, during operation, transmits the data and the DMRS to a receiving device within the slot, and executes transmission of the DMRS in the repetition of the data based on the DMRS allocation, and a transceiver; Comprising Symbols that are not valid for uplink transmission are allocated to the symbols between the repetitions of the data Transmitting device.

2. The transmitting device transmits the data to the receiving device over the uplink The transceiver further receives, during operation, control signaling including a DMRS allocation indicator indicating the DMRS allocation for the repetition of the data from the receiving device The circuit obtains the DMRS allocation for each transmission of the repetition of the data by evaluating the control signaling during operation The transmitting device according to claim 1.

3. The DMRS allocation indicator is included in upper layer signaling The transmitting device according to claim 2.

4. A circuit that, during operation, allocates repeated data and a demodulation reference signal (DMRS) to time-domain resources and obtains a DMRS allocation indicating whether the DMRS is allocated to the time-domain resources, wherein each repetition of the data includes a number of consecutive symbols less than a slot, and a circuit; A transceiver that, during operation, receives the data and the DMRS from a transmitting device within the slot, and executes reception of the DMRS in the repetition of the data based on the DMRS allocation, and a transceiver; Comprising Symbols that are not valid for uplink transmission are allocated to the symbols between the time-domain resources Receiving device.

5. A step of allocating repeated data and a demodulation reference signal (DMRS) to time-domain resources, wherein each repetition of the data includes a number of consecutive symbols less than a slot, and allocating; Obtaining a DMRS allocation indicating whether the DMRS is allocated to the time-domain resources In the slot, transmitting the data and the DMRS to a receiving device, the transmitting step including performing transmission of the DMRS in repetition of the data based on the DMRS allocation. including Symbols that are not valid for uplink transmission are allocated to symbols between the time domain resources. Transmission method.

6. Repeating initial transmission data and allocating a demodulation reference signal (DMRS) to time domain resources, and obtaining a DMRS allocation indicating whether the DMRS is allocated to the time domain resources, wherein each repetition includes a number of consecutive symbols less than a slot, the obtaining step. Receiving, in the slot, from a transmitting device, data and the DMRS, the receiving step including performing reception of the DMRS in repetition of the data based on the DMRS allocation. including Symbols that are not valid for uplink transmission are allocated to symbols between the time domain resources. Receiving method.

7. An integrated circuit for controlling processing of a transmitting device that transmits data to a receiving device in a communication system, the processing including Repeating the data and allocating a demodulation reference signal (DMRS) to time domain resources, and obtaining a DMRS allocation indicating whether the DMRS is allocated to the time domain resources, wherein each repetition of the data includes a number of consecutive symbols less than a slot, the obtaining processing. In the slot, transmitting the data and the DMRS to the receiving device, the transmitting processing including performing transmission of the DMRS in repetition of the data based on the DMRS allocation. including Symbols that are not valid for uplink transmission are allocated to symbols between the time domain resources. Integrated circuit.

8. An integrated circuit for controlling processing of a receiving device that receives data from a transmitting device in a communication system, the processing including Repeating the data and allocating a demodulation reference signal (DMRS) to time domain resources, and obtaining a DMRS allocation indicating whether the DMRS is allocated to the time domain resources, wherein each repetition of the data includes a number of consecutive symbols less than a slot, the obtaining processing. A receiving process of receiving the data and the DMRS within the slot from the transmission device, the receiving process including executing reception of the DMRS in repetition of the data based on the DMRS allocation including symbols that are not valid for uplink transmission are allocated to symbols between the time domain resources Integrated circuit

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