terminal

By repeating PDSCH in the frequency direction and optimizing resource allocation, the terminal improves coverage and reduces error rates in 5G NR systems, addressing inefficiencies in transmitting small data packets.

JP7842270B2Active Publication Date: 2026-04-07NTT DOCOMO INC
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Patent Information

Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Filing Date
2025-03-06
Publication Date
2026-04-07

AI Technical Summary

Technical Problem

Existing 5G NR systems face challenges in efficiently transmitting physical downlink data channels due to limited coverage and resource wastage when sending small data packets, leading to increased error rates.

Method used

The terminal (UE200) employs frequency-direction repetition of PDSCH, adjusting modulation and coding schemes, and reporting UE capabilities to optimize resource allocation for improved coverage and error reduction.

Benefits of technology

This approach enhances coverage and reduces error rates by efficiently utilizing resources for smaller data transmissions, achieving higher quality and more reliable PDSCH reception.

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Abstract

To provide a terminal that copes with more efficient physical downlink data channel reception according to the coverage enhancement, for realization of coverage enhancement in New Radio (NR).SOLUTION: A radio communication system includes a terminal 200 comprising: a receiving unit for receiving physical downlink data channels; and a controlling unit that assumes that physical downlink data channels assigned in the same symbol or slot in the time direction are also assigned in the frequency direction in the symbol or slot.SELECTED DRAWING: Figure 3
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Description

Technical Field

[0001] The present disclosure relates to a terminal that receives a physical downlink data channel.

Background Art

[0002] The 3rd Generation Partnership Project (3GPP) is standardizing the 5th generation mobile communication system (also called 5G, New Radio (NR), or Next Generation (NG)), and is also proceeding with the standardization of the next generation, called Beyond 5G, 5G Evolution, or 6G.

[0003] For example, in 3GPP Release-17, it has been agreed to study coverage enhancement (CE) in NR (Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

[0005] In order to achieve coverage expansion in NR, we evaluated the link budgets (Hardware link budget) of physical channels (PDSCH (Physical Downlink Shared Channel), PUSCH (Physical Uplink Shared Channel), PDCCH (Physical Downlink Control Channel), and PUCCH (Physical Uplink Control Channel)). The results showed that there is room for improvement, at least for PDSCH (Physical Downlink Data Channel).

[0006] Regarding the downlink (DL) transmit power of a ground network base station (gNB), the power spectrum density (PSD) is generally constant regardless of the bandwidth of the transmitted signal. Therefore, the more resource blocks (RBs) allocated to the transmitting resources, the greater the total transmit power.

[0007] NR allows for flexible allocation of PDSCH time and frequency resources. For example, increasing the number of RBs and decreasing the coding rate can increase the total transmit power.

[0008] The coding rate is determined for each Modulation and Coding Scheme (MCS) index, and the transport block (TB) size is determined by the MCS and the amount of allocated resources. Therefore, increasing the amount of allocated resources will not result in a coding rate below that of MCS=0. Furthermore, increasing the amount of allocated resources to increase the total transmission power will increase the TB size, resulting in wasted resources when sending small data.

[0009] Therefore, it is desirable to utilize allocated resources to enable the transmission of smaller data with a lower error rate.

[0010] Therefore, the following disclosure is made in light of these circumstances and aims to provide a terminal that can support more efficient PDSCH reception in response to coverage expansion.

[0011] One aspect of this disclosure is a terminal (UE200) comprising a receiving unit (wireless signal transmitting / receiving unit 210) that receives a physical downlink data channel, and a control unit (control unit 270) that assumes the physical downlink data channel is repeated in the frequency direction within the same time domain. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic diagram of the overall configuration of the wireless communication system 10. [Figure 2] Figure 2 shows an example of the configuration of wireless frames, subframes, and slots used in the wireless communication system 10. [Figure 3] Figure 3 is a functional block diagram of the UE200. [Figure 4] Figure 4 shows the MIL evaluation results for the physical channel in FR1. [Figure 5] Figure 5 shows the MIL evaluation results for the physical channel in FR2. [Figure 6] Figure 6 shows an example of the relationship between the bandwidth and power density (PSD) of a transmitted signal. [Figure 7] Figure 7 shows an example of PDSCH resource allocation (continuous arrangement) related to Operation Example 1. [Figure 8] Figure 8 shows an example of PDSCH resource allocation (non-contiguous arrangement) related to Operation Example 1. [Figure 9] Figure 9 shows an example of a communication sequence related to the repetition setting in the frequency direction of PDSCH. [Figure 10] Figure 10 shows an example configuration of PDSCH-Config. [Figure 11] Figure 11 shows an example of the hardware configuration of the UE200.

Best Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments will be described based on the drawings. Note that the same reference numerals are assigned to the same or similar functions and configurations, and the description thereof will be omitted as appropriate.

[0014] (1) Overall schematic configuration of the wireless communication system FIG. 1 is an overall schematic configuration diagram of a wireless communication system 10 according to this embodiment. The wireless communication system 10 is a wireless communication system according to 5G New Radio (NR), and includes a Next Generation - Radio Access Network 20 (hereinafter, NG - RAN20) and a terminal 200 (User Equipment 200, hereinafter, UE200).

[0015] Note that the wireless communication system 10 may also be a wireless communication system according to a method called Beyond 5G, 5G Evolution, or 6G.

[0016] NG - RAN20 includes a radio base station 100A (hereinafter, gNB100A) and a radio base station 100B (hereinafter, gNB100B). Note that the specific configuration of the wireless communication system 10 including the number of gNBs and UEs is not limited to the example shown in FIG. 1.

[0017] NG - RAN20 actually includes a plurality of NG - RAN Nodes, specifically, gNBs, and is connected to a core network (5GC, not shown) according to 5G. Note that NG - RAN20 and 5GC may also be simply expressed as "network".

[0018] gNB100A and gNB100B are radio base stations compliant with NR, and perform wireless communication with UE200 according to NR. gNB100A, gNB100B, and UE200 can support Massive MIMO that generates more directive beams by controlling wireless signals transmitted from a plurality of antenna elements, Carrier Aggregation (CA) that bundles and uses a plurality of Component Carriers (CCs), and Dual Connectivity (DC) that simultaneously communicates between the UE and each of a plurality of NG-RAN Nodes, etc.

[0019] Wireless communication system 10 supports FR1 and FR2. The frequency bands for each FR are as follows.

[0020] · FR1: 410 MHz to 7.125 GHz · FR2: 24.25 GHz to 52.6 GHz In FR1, a Sub-Carrier Spacing (SCS) of 15, 30, or 60 kHz is used, and a bandwidth (BW) of 5 to 100 MHz may be used. FR2 is at a higher frequency than FR1, and an SCS of 60 or 120 kHz (240 kHz may be included) is used, and a bandwidth (BW) of 50 to 400 MHz may be used.

[0021] Furthermore, wireless communication system 10 may also support a frequency band higher than the frequency band of FR2. Specifically, wireless communication system 10 may support a frequency band exceeding 52.6 GHz and up to 114.25 GHz.

[0022] Also, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform - Spread (DFT-S-OFDM) having a larger Sub-Carrier Spacing (SCS) may be applied. Furthermore, DFT-S-OFDM may be applied not only to the uplink (UL) but also to the downlink (DL).

[0023] Figure 2 shows an example of the configuration of wireless frames, subframes, and slots used in the wireless communication system 10.

[0024] As shown in Figure 2, one slot consists of 14 symbols, and the larger (wider) the SCS, the shorter the symbol duration (and slot duration). Note that the number of symbols constituting one slot does not necessarily have to be 14 (for example, 28 or 56 symbols). Also, the number of slots per subframe may differ depending on the SCS. Furthermore, although not shown in the figure, wider intervals for the SCS, such as 480kHz or 960kHz, may also be used.

[0025] The time direction (t) shown in Figure 2 may also be called the time domain, symbol period, or symbol time. The frequency direction may also be called the frequency domain, resource block, subcarrier, BWP (Bandwidth part), etc.

[0026] Furthermore, the wireless communication system 10 can support coverage enhancement (CE) to broaden the coverage of the cells formed by gNB100A (and gNB100B, hereinafter the same). Coverage enhancement may provide a mechanism to increase the reception success rate of various physical channels.

[0027] In this embodiment, the wireless communication system 10 (gNB100A) can support repeated transmission of the physical downlink data channel, specifically the PDSCH (Physical Downlink Shared Channel).

[0028] (2) Functional block configuration of the wireless communication system Next, the functional block configuration of the wireless communication system 10 will be described. Specifically, the functional block configuration of UE200 will be described.

[0029] Figure 3 is a functional block diagram of the UE200. As shown in Figure 3, the UE200 comprises a wireless signal transmission / reception unit 210, an amplifier unit 220, a modulation / demodulation unit 230, a control signal / reference signal processing unit 240, an encoding / decoding unit 250, a data transmission / reception unit 260, and a control unit 270.

[0030] The wireless signal transceiver unit 210 transmits and receives wireless signals in accordance with NR. The wireless signal transceiver unit 210 supports Massive MIMO, CA which uses multiple CCs bundled together, and DC which communicates simultaneously between the UE and each of the two NG-RAN Nodes.

[0031] Specifically, the wireless signal transmission / reception unit 210 transmits and receives wireless signals via various physical channels. In particular, in this embodiment, the wireless signal transmission / reception unit 210 constitutes a receiving unit that receives a physical downlink data channel. Specifically, the physical downlink data channel may be interpreted as a PDSCH (Physical Downlink Shared Channel). A PDSCH may also be called a physical downlink shared channel.

[0032] Furthermore, the wireless signal transceiver unit 210 constitutes a transmitter that transmits information about the UE200's capabilities regarding the reception of physical downlink data channels to the network.

[0033] Specifically, the wireless signal transceiver 210 can transmit capability information to the network indicating its ability to handle repetition in the frequency direction of the PDSCH (Physical Downlink Data Channel). The capability information of the UE200 may be interpreted as UE capability information as defined in 3GPP TS38.331, etc.

[0034] The wireless signal transceiver 210 can transmit UE capability information via a predetermined uplink physical channel. The content of the UE capability information related to PDSCH reception will be described later.

[0035] The amplifier section 220 consists of components such as a PA (Power Amplifier) ​​and an LNA (Low Noise Amplifier). The amplifier section 220 amplifies the signal output from the modulation / demodulation section 230 to a predetermined power level. The amplifier section 220 also amplifies the RF signal output from the wireless signal transmission / reception section 210.

[0036] The modulation / demodulation unit 230 performs data modulation / demodulation, transmit power setting, and resource block allocation for each predetermined communication destination (such as gNB100A). The modulation / demodulation unit 230 may apply Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform - Spread (DFT-S-OFDM). Furthermore, DFT-S-OFDM may be used not only for the uplink (UL) but also for the downlink (DL).

[0037] The control signal / reference signal processing unit 240 performs processing related to various control signals transmitted and received by the UE200, and processing related to various reference signals transmitted and received by the UE200.

[0038] Specifically, the control signal / reference signal processing unit 240 receives various control signals, such as radio resource control layer (RRC) control signals, transmitted from gNB100A (or gNB100B, hereinafter the same) via a predetermined control channel. The control signal / reference signal processing unit 240 also transmits various control signals to gNB100A via a predetermined control channel.

[0039] The control signal / reference signal processing unit 240 performs processing using reference signals (RS) such as the Demodulation Reference Signal (DMRS) and the Phase Tracking Reference Signal (PTRS).

[0040] DMRS is a terminal-specific, known reference signal (pilot signal) between the base station and the terminal used to estimate the fading channel used for data demodulation. PTRS is a terminal-specific reference signal intended to estimate phase noise, which is a problem in the high-frequency band.

[0041] In addition to DMRS and PTRS, the reference signals may also include Channel State Information-Reference Signal (CSI-RS), Sounding Reference Signal (SRS), and Positioning Reference Signal (PRS) for location information.

[0042] Channels include control channels and data channels. Control channels include PDCCH (Physical Downlink Control Channel), PUCCH (Physical Uplink Control Channel), RACH (Random Access Channel, Downlink Control Information (DCI) including Random Access Radio Network Temporary Identifier (RA-RNTI)), and Physical Broadcast Channel (PBCH), among others.

[0043] Data channels include PDSCH (Physical Downlink Shared Channel) and PUSCH (Physical Uplink Shared Channel), among others. "Data" can refer to data transmitted through a data channel.

[0044] Furthermore, the physical channels may include at least PDCCH, PUCCH, PUSCH, and PDSCH.

[0045] The encoding / decoding unit 250 performs data splitting / concatenation and channel coding / decoding for each predetermined communication destination (such as gNB100A).

[0046] Specifically, the encoding / decoding unit 250 divides the data output from the data transmission / reception unit 260 into predetermined sizes and performs channel coding on the divided data. The encoding / decoding unit 250 also decodes the data output from the modulation / demodulation unit 230 and concatenates the decoded data.

[0047] The data transmission / reception unit 260 performs the transmission and reception of Protocol Data Units (PDUs) and Service Data Units (SDUs). Specifically, the data transmission / reception unit 260 performs assembly / decomposition of PDUs / SDUs at multiple layers (such as the Media Access Control Layer (MAC), Radio Link Control Layer (RLC), and Packet Data Convergence Protocol Layer (PDCP)). In addition, the data transmission / reception unit 260 performs error correction and retransmission control of data based on Hybrid ARQ (Hybrid automatic repeat request).

[0048] The control unit 270 controls each functional block that constitutes the UE200. In particular, in this embodiment, the control unit 270 can perform various controls related to physical channels in order to support coverage expansion (CE).

[0049] Specifically, the control unit 270 may assume that the PDSCH (Physical Downlink Data Channel) is repeated in the frequency direction. The repetition of a PDSCH in the frequency direction means that a PDSCH allocated to a certain region (resource such as a symbol or slot) in the time direction is also allocated multiple times in the frequency direction within that same time region.

[0050] In other words, the control unit 270 can assume that the PDSCH is repeated in the frequency direction within the same time domain.

[0051] PDSCHs that are repeated in the frequency direction (which may also be called PDSCH resources) may be adjacent in the frequency direction or may be spaced apart with a certain interval between them. In other words, multiple PDSCHs may be assigned consecutively to adjacent subcarriers, or they may be assigned with several subcarriers in between.

[0052] Thus, the control unit 270 may assume that the PDSCH is repeated at intervals in the frequency direction, or it may assume that the PDSCH is repeated continuously in the frequency direction.

[0053] The control unit 270 may change at least one of the modulation and coding scheme (MCS) and the coding rate based on the frequency repetition of the PDSCH.

[0054] For example, if the number of repetitions of the PDSCH (referred to as the number of repetitions) is 4 (i.e., 4 PDSCHs are repeated), the control unit 270 may set the coding rate to 1 / 4 of the rate when there are no repetitions. The control unit 270 may also change the MCS depending on the number of repetitions or whether or not there are repetitions. For example, if the number of repetitions of the PDSCH is 2, the control unit 270 may set an MCS that is 3 smaller than the instructed MCS.

[0055] The control unit 270 may assume the frequency-direction repeatability of the PDSCH as described above based on signaling from the network. Specifically, the control unit 270 may assume the frequency-direction repeatability of the PDSCH based on signaling from downlink control information (DCI), media access control layer control elements (MAC-CE), or radio resource control layer (RRC).

[0056] The DCI, MAC-CE, or RRC signaling may include information indicating the presence or absence of repeats in the frequency direction of the PDSCH, the number of repeats, and the interval between repeats. Specific examples of such signaling will be described further later.

[0057] (3) Operation of the wireless communication system Next, the operation of the wireless communication system 10 will be described. Specifically, the operation related to the reception of a physical downlink data channel (PDSCH) compatible with coverage extension (CE) will be described.

[0058] (3.1) Premise The Study Item set by 3GPP (see RP-193240) envisions the implementation of coverage extensions in both the FR1 and FR2 frequency bands.

[0059] The target scenarios include service provision from an outdoor (O) gNB to an indoor (I) UE (in the case of FR1) and service provision from an indoor gNB to an indoor UE (in the case of FR2). Coverage expansion in urban, suburban, and rural areas (including rural areas with long-distance communication) is also targeted.

[0060] Furthermore, the main target services are VoIP (Voice over IP) and eMBB (enhanced Mobile Broadband).

[0061] Based on these scenarios and target services, an evaluation of the link budget (Hardware link budget, also known as MIL) defined by 3GPP for physical channels, specifically PDSCH, PUSCH, PDCCH, and PUCCH, suggests that improvements are needed, as shown below.

[0062] (FR1) • PUSCH: Approximately 13 dB (eMBB) • PDSCH: Approximately 5-6 dB (VoIP and eMBB) ·PDCCH: Approximately 5 dB (VoIP) (FR2) • PUSCH: Approximately 21 dB (eMBB) ·PDSCH: Approximately 16 dB (VoIP), approximately 8 dB (eMBB) ·PDCCH: Approx. 18 dB (VoIP) Figure 4 shows the MIL evaluation results for the physical channel in FR1. Figure 5 shows the MIL evaluation results for the physical channel in FR2.

[0063] The following describes the improvements made to PDSCH to support coverage expansion.

[0064] Figure 6 shows an example of the relationship between the bandwidth and power density (PSD) of the transmitted signal. As shown in Figure 6, for the downlink (DL) transmit power of the gNB100A (and gNB100B, hereafter the same), the power density (PSD: Power Spectrum Density) is generally constant regardless of the bandwidth of the transmitted signal. Therefore, the more resource blocks (RBs) allocated to the resources being transmitted, the greater the total transmit power.

[0065] NR allows for flexible allocation of PDSCH time and frequency resources. For example, increasing the number of RBs and decreasing the coding rate can increase the total transmit power.

[0066] The coding rate is determined for each Modulation and Coding Scheme (MCS) index, and the transport block (TB) size is determined by the MCS and the amount of allocated resources. Therefore, increasing the amount of allocated resources will not result in a coding rate below that of MCS=0. Furthermore, increasing the amount of allocated resources to increase the total transmission power will increase the TB size, resulting in wasted resources when sending small data.

[0067] Therefore, it is desirable to utilize allocated resources to enable the transmission of smaller data with a lower error rate.

[0068] To utilize allocated resources to send smaller data with a lower error rate, the following methods can be considered:

[0069] (i) Introduce a new MCS table that specifies a lower coding rate. (ii) Determine the transport block (TB) size from the allocated (partial) resource amount and repeat the remaining resources in the frequency direction.

[0070] (3.2) Operation overview The following describes an example of operation when the method described in (ii) above is applied to PDSCH. This makes it possible to extend the coverage of PDSCH by introducing repetition in the frequency direction.

[0071] Specifically, the wireless communication system 10 can perform the following operations:

[0072] • (Example of operation 1): Repetition of PDSCH in the frequency direction • The PDSCH resources set by DCI are repeatedly set in the frequency direction. The number of repetitions can be set arbitrarily. • The MCS and / or coding rate may be changed depending on the number of repetitions. The interval between repetitions can be set arbitrarily. • (Example of operation 2): How to set the repetition in the frequency direction of PDSCH • Notify via DCI (for example, define a new DCI format and extend the Frequency Domain Resource Assignment (FDRA) or fields to be notified) • Notify via MAC-CE • Configured via RRC signaling (for example, using PDSCH-Config) • (Example of operation 3): UE capability information The UE (terminal) reports its capability regarding PDSCH repetition in the frequency direction, for example, whether it can handle the following: • Whether PDSCH supports repetition in the frequency direction. • Number of repetitions and repetition interval in the frequency direction of PDSCH

[0073] (3.3) Example of operation 1 In this example, repetition in the frequency direction is performed to obtain the frequency diversity gain of the PDSCH.

[0074] Figure 7 shows an example of PDSCH resource allocation (contiguous arrangement) related to Operation Example 1. Figure 8 shows an example of PDSCH resource allocation (non-contiguous arrangement) related to Operation Example 1. Figures 7 and 8 show examples where the number of repetitions is 4.

[0075] As shown in Figures 7 and 8, in this example, the PDSCH resources set by DCI can be repeatedly set in the frequency direction. In other words, PDSCH resources may be repeatedly allocated in the frequency direction.

[0076] Note that the number of repetitions is not limited to 4; any number can be set (for example, Number of Repetition = 2, 4, 8, 16).

[0077] Furthermore, at least one of the MCS and the coding rate may be changed depending on the number of repetitions. For example, if the number of repetitions is 4, the coding rate may be 1 / 4 of the rate when there are no repetitions. In other words, the coding rate may be decreased as the number of repetitions increases.

[0078] Furthermore, as shown in Figure 7 (continuous arrangement) and Figure 8 (discontinuous arrangement), repeated PDSCH resources may be set (allocated) continuously in the frequency direction, or they may be set (allocated) with a certain interval (gap) between them.

[0079] The UE200 may anticipate such frequency-direction repetitions of PDSCH. Specifically, it may anticipate such repetitions based on the setting method described below.

[0080] (3.4) Example of operation 2 Figure 9 shows an example of a communication sequence related to the repetition setting in the frequency direction of the PDSCH.

[0081] As shown in Figure 9, the UE200 may transmit capability information to the network indicating the UE200's capability with respect to repetition in the frequency direction of the PDSCH (S10).

[0082] The UE capability information may include whether the PDSCH supports repeats in the frequency direction, the number of repeats that can be supported, and the repeat interval. Alternatively, the UE capability information may include only one of these elements (for example, whether repeats are supported). Further specific examples of this UE capability information will be explained in Operation Example 3.

[0083] The network determines the PDSCH resource based on the received UE capability information and the network's capabilities (S20). Specifically, the network may determine whether or not there are repeats in the frequency direction of the PDSCH, the number of repeats, and the repeat interval.

[0084] The network notifies the UE200 of the information regarding the determined PDSCH resource (S30). Specifically, as described above, this information may be notified by DCI, MAC-CE, or RRC signaling.

[0085] Based on the information of the notified PDSCH resource, UE200 configures PDSCH reception (S40). Specifically, based on the information of the notified PDSCH resource, UE200 may configure settings for PDSCH repetition in the frequency direction.

[0086] As mentioned above, the network may notify information about the determined PDSCH resources through DCI, MAC-CE, or RRC signaling, but specifically, it can notify as follows:

[0087] For example, when notification is made via DCI, a new DCI format may be defined, and when scheduling PDSCH, the presence or absence of repetition and / or the number of repetitions may also be set.

[0088] In this case, the FDRA may also be extended to notify the number of repetitions and / or intervals of existing allocated resources by joint coding, in addition to the starting position of existing allocated resources, the number of RBs and / or resource block groups (RBGs).

[0089] Alternatively, a new field may be added to the existing DCI format to indicate the number of repetitions and / or the interval.

[0090] When notification is sent via MAC-CE, a new MAC-CE separate from the existing MAC-CE may be used.

[0091] When using RRC signaling, that is, notification via RRC parameters, information elements of PDSCH-Config may be used, for example. Figure 10 shows an example of PDSCH-Config configuration.

[0092] As shown in Figure 10, the number of repetitions in the frequency direction of the PDSCH (e.g., ENUMERATED (n2, n4, n8, n16)) may be notified using the pdsch-Repetition_FrequencyDomain field. Alternatively, any value (e.g., INTEGER(0…20)) may be set.

[0093] Furthermore, the Repetition interval may be the same as the number of RBs set (assigned) to the PDSCH, or it may be an arbitrary value. If an arbitrary value is used, the Repetition interval may be notified using the Repetition_offset field, as shown in Figure 10.

[0094] (3.5) Example of operation 3 The UE200 capability information regarding PDSCH repetition in the frequency direction may include the following elements:

[0095] • Whether PDSCH supports repetition in the frequency direction. • Number of repetitions and / or repetition intervals in the frequency direction of PDSCH Furthermore, the UE200 may report at least one of the following regarding the corresponding frequencies:

[0096] • Whether or not a unified solution is available for all frequencies (whether or not it can be handled as a UE). • Compatibility for each frequency (band) • Compatibility for each frequency range (FR1, FR2) Furthermore, the UE200 may report at least one of the following regarding the corresponding duplex scheme:

[0097] • Feasibility of implementing a reconnection method as a UE (Unified Engagement) • Compatibility for each duplexing method (TDD, FDD)

[0098] (4) Action and Effects According to the embodiment described above, the following effects can be obtained. Specifically, the UE200 can be assumed to have PDSCH repeated in the frequency direction within the same time domain. Therefore, the UE200 can more easily obtain the frequency diversity gain of PDSCH.

[0099] Furthermore, since the TB size can be determined from the amount of resources (part of them) allocated to the PDSCH, and the remaining resources can be allocated to repetition in the frequency direction, it is easier to utilize the resources allocated to the PDSCH to transmit smaller data with a lower error rate.

[0100] In other words, according to the wireless communication system 10, the UE200 can support more efficient PDSCH reception with coverage extension, and can achieve higher quality coverage extension.

[0101] In this embodiment, the UE200 can be assumed to have PDSCH repeated at intervals in the frequency direction. Therefore, the UE200 can more easily obtain the frequency diversity gain of the PDSCH, and can achieve higher quality coverage extension.

[0102] In this embodiment, the UE200 can change at least one of the MCS or coding rate based on the repetition of the PDSCH in the frequency direction. This enables efficient data transmission in accordance with the amount of resources allocated to the PDSCH.

[0103] In this embodiment, the UE200 can anticipate the frequency-direction repetition of the PDSCH based on DCI, MAC-CE, or RRC signaling. Therefore, the UE200 can reliably recognize the frequency-direction repetition setting of the PDSCH in advance.

[0104] In this embodiment, the UE200 can transmit UE capability information to the network, indicating the PDSCH's ability to handle repetitions in the frequency direction. Therefore, the network can configure an appropriate PDSCH according to the capabilities of the UE200.

[0105] (5) Other embodiments Although embodiments have been described above, it will be obvious to those skilled in the art that the invention is not limited to those embodiments described and that various modifications and improvements are possible.

[0106] For example, in the embodiment described above, PDSCH was used as an example, but PDSCH may be called by a different name. Specifically, any data channel in the downlink (DL) direction may be called by a name different from PDSCH.

[0107] Furthermore, in the embodiments described above, the UE200 is assumed to assume repetition in the frequency direction of the PDSCH based on DCI. However, if the presence or absence of such repetition is notified by MAC-CE or RRC signaling, the assumption of such repetition does not need to be based on DCI for PDSCH reception (e.g., Format 1_1).

[0108] Furthermore, the block diagram (Figure 3) used in the description of the embodiments above shows functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Moreover, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may be realized by combining the above one device or the above multiple devices with software.

[0109] Functions include, but are not limited to, judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. In any case, as mentioned above, the method of implementation is not particularly limited.

[0110] Furthermore, the UE200 described above may function as a computer that processes the wireless communication method of this disclosure. Figure 11 shows an example of the hardware configuration of the UE200. As shown in Figure 11, the UE200 may be configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, and bus 1007.

[0111] In the following explanation, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the device may include one or more of the devices shown in the diagram, or it may be configured to omit some of the devices.

[0112] Each functional block of the UE200 (see Figure 3) is implemented by any hardware element of the computer device, or a combination of such hardware elements.

[0113] Furthermore, each function in the UE200 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of the reading and writing of data in the memory 1002 and storage 1003.

[0114] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, and so on.

[0115] Furthermore, the processor 1001 reads programs (program code), software modules, data, etc., from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. Moreover, the above-mentioned various processes may be executed by one processor 1001, or by two or more processors 1001 simultaneously or sequentially. The processor 1001 may be implemented by one or more chips. The program may be transmitted from a network via a telecommunications line.

[0116] Memory 1002 is a computer-readable recording medium and may consist of at least one of the following: Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), Random Access Memory (RAM), etc. Memory 1002 may also be called a register, cache, main memory, etc. Memory 1002 can store a program (program code), software modules, etc., that can execute a method according to one embodiment of this disclosure.

[0117] Storage 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disc, a digital multipurpose disc, a Blu-ray® disc), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. Storage 1003 may also be called an auxiliary storage device. The recording medium described above may also be, for example, a database, server, or other suitable medium including at least one of memory 1002 and storage 1003.

[0118] The communication device 1004 is hardware (transceiver / receiver device) for communicating between computers via at least one of a wired network and a wireless network, and is also called a network device, network controller, network card, communication module, etc.

[0119] The communication device 1004 may be configured to include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD).

[0120] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0121] Furthermore, each device, such as the processor 1001 and the memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0122] Furthermore, the device may include hardware such as a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), and a field-programmable gate array (FPGA), and some or all of each functional block may be implemented by such hardware. For example, processor 1001 may be implemented using at least one of these hardware components.

[0123] Furthermore, notification of information is not limited to the embodiments / models described herein and may be carried out by other means. For example, notification of information may be carried out by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (e.g., RRC signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB))), other signals, or combinations thereof. RRC signaling may also be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0124] Each aspect / embodiment described herein may be applied to at least one of the following: Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA®, GSM®, CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth®, and other appropriate systems, as well as next-generation systems extended based thereon. Furthermore, multiple systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A with 5G).

[0125] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

[0126] The specific operations described in this disclosure as being performed by a base station may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal can be performed by the base station and at least one other network node (for example, an MME or S-GW, but not limited to these). Although the above example illustrates the case where there is one other network node besides the base station, it may also be a combination of multiple other network nodes (for example, an MME and an S-GW).

[0127] Information and signals (such as data) can be output from a higher layer (or lower layer) to a lower layer (or higher layer). Input and output may occur via multiple network nodes.

[0128] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be sent to other devices.

[0129] The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0130] Each aspect / embodiment described herein may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0131] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0132] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or Digital Subscriber Line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0133] The information, signals, etc. described in this disclosure may be represented using any of the various different technologies. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0134] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0135] The terms “system” and “network” as used in this disclosure are interchangeable.

[0136] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or other corresponding information. For example, wireless resources may be indicated by an index.

[0137] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not restrictive in any way.

[0138] In this disclosure, terms such as "Base Station (BS)," "wireless base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0139] A base station can house one or more (e.g., three) cells (also called sectors). If a base station houses multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, each of which can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0140] The terms "cell" or "sector" refer to a portion or all of the coverage area of ​​at least one of the base stations and base station subsystems that provide communication services in this coverage.

[0141] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0142] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate term.

[0143] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may be a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0144] Furthermore, the term "base station" in this disclosure may be interpreted as "mobile station" (user terminal, hereinafter the same). For example, each aspect / embodiment of this disclosure may be applied to a configuration in which communication between a base station and a mobile station is replaced with communication between multiple mobile stations (which may be called, for example, Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). In this case, the mobile station may have the functions that a base station has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc. may be interpreted as side channel.

[0145] Similarly, the term "mobile station" in this disclosure may be interpreted as "base station." In this case, the base station may be configured to have the functions that a mobile station has. A wireless frame may consist of one or more frames in the time domain. Each of these one or more frames in the time domain may be called a subframe. A subframe may further consist of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0146] Numerology may be communication parameters applied to at least one of the transmission and reception of a signal or channel. Numerology may include, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain.

[0147] A slot may consist of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol). A slot may also be a time unit based on neurology.

[0148] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. Minislots may also be called subslots. Minislots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called a PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called a PDSCH (or PUSCH) mapping type B.

[0149] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Different names may be used for each of these terms.

[0150] For example, one subframe may be called a Transmit Time Interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. In other words, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0151] Here, TTI refers to, for example, the smallest unit of time for scheduling in wireless communication. For example, in an LTE system, the base station schedules each user terminal to allocate wireless resources (such as the frequency bandwidth and transmission power available to each user terminal) in TTI units. However, the definition of TTI is not limited to this.

[0152] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Given a TTI, the actual time interval (e.g., number of symbols) to which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI.

[0153] Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute this minimum time unit of scheduling may be controlled.

[0154] A TTI with a time length of 1ms may also be called a normal TTI, long TTI, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may also be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini slot, sub slot, slot, etc.

[0155] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

[0156] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology.

[0157] Furthermore, the time domain of the RB may contain one or more symbols and may be the length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc., may each consist of one or more resource blocks.

[0158] One or more RBs may also be called a Physical RB (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB pair, RB pair, etc.

[0159] Furthermore, a resource block may consist of one or more resource elements (REs). For example, one RE may be a radio resource area comprising one subcarrier and one symbol.

[0160] A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a given neurology on a given carrier. Here, the common RBs may be identified by an index of the RBs relative to the carrier's common reference point. PRBs may be defined and numbered within a BWP.

[0161] A BWP may include BWPs for UL (UL BWP) and BWPs for DL ​​(DL BWP). One or more BWPs may be set within a single carrier for a UE.

[0162] At least one of the configured BWPs may be active, and the UE does not need to assume that it will send or receive a given signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0163] The structures described above, such as wireless frames, subframes, slots, minislots, and symbols, are merely illustrative. For example, the number of subframes included in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, and the number of symbols, symbol length, and cyclic prefix (CP) length within the TTI can be varied in various ways.

[0164] The terms “connected,” “coupled,” or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0165] The reference signal can also be abbreviated as Reference Signal (RS), and may be called a pilot depending on the applicable standard.

[0166] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0167] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.

[0168] Any reference to elements using designations such as “First,” “Second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to the First and Second elements do not imply that only two elements may be employed therein, or that the First element must precede the Second element in any way.

[0169] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0170] In this disclosure, if articles are added through translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0171] As used in this disclosure, the terms “determining” and “determining” may encompass a wide variety of actions. “Determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiry (e.g., searching in a table, database, or other data structure), and ascertaining. “Determining” may also include, for example, receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, and accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having been "judged" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having been "judged" or "decided" after some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0172] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0173] Although the present disclosure has been described in detail above, it will be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the intent and scope of the present disclosure as defined by the claims. Therefore, the descriptions in the present disclosure are illustrative and not intended to be restrictive in any way. [Explanation of Symbols]

[0174] 10 Wireless communication systems 20 NG-RAN 100A, 100B gNB UE 200 210 Wireless signal transmission and reception unit 220 Amplifier section 230 Modulation / Demodulation Section 240 Control signal / reference signal processing unit 250 Encoding / Decoding Unit 260 Data transmission / reception unit 270 Control Unit 1001 Processor 1002 memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus

Claims

1. A receiving unit that receives the physical downlink data channel, A control unit that assumes that multiple physical downlink data channels, each assigned to the same symbol or slot in the time direction, are also assigned to the same symbol or slot in the frequency direction. Equipped with, The control unit is a terminal that modifies at least one of the modulation coding scheme and coding rate based on the repetition in the frequency direction of the physical downlink data channel.

2. The terminal according to claim 1, wherein the control unit assumes that the physical downlink data channels are repeated with intervals in the frequency direction.

3. The terminal according to claim 1, wherein the control unit assumes repetition in the frequency direction of the physical downlink data channel based on downlink control information, control elements of the media access control layer, or signaling of the wireless resource control layer.

4. The terminal according to claim 1, further comprising a transmitting unit that transmits capability information indicating the ability of the physical downlink data channel to handle repetition in the frequency direction.

5. The terminal according to claim 1, wherein the control unit sets the coding rate to 1 / X when there are no repetitions, if the number of repetitions of the physical downlink data channel is X.

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