User equipment, base station and communication system

Abstract

To provide a highly reliable communication system.SOLUTION: A communication system includes a base station and a plurality of terminal devices configured to be able to wirelessly communicate with the base station. When one slot includes a sounding reference signal (SRS) symbol range consisting of one or more symbols allocated to an SRS of a first terminal device, a first symbol range consisting of one or more symbols before the SRS symbol range, and a second symbol range consisting of one or more symbols after the SRS symbol range, a second terminal device different from the first terminal device performs uplink communication to the base station in at least one of the first symbol range and the second symbol range.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a communication system or the like that performs wireless communication between a communication terminal device such as a mobile terminal device and a base station device. [Background technology]

[0002] 3GPP (3rd Generation Partnership Project), a standardization organization for mobile communication systems, is considering a communication method called Long Term Evolution (LTE) for the wireless section and System Architecture Evolution (SAE) for the overall system configuration including the core network and radio access network (hereinafter collectively referred to as the network) (see, for example, Non-Patent Documents 1 to 5). This communication method is also called the 3.9G (3.9 Generation) system.

[0003] LTE uses OFDM (Orthogonal Frequency Division Multiplexing) for downlink and SC-FDMA (Single Carrier Frequency Division Multiple Access) for uplink as its access method. Unlike W-CDMA (Wideband Code Division Multiple Access), LTE does not include circuit switching and is only a packet communication method.

[0004] The decisions made by 3GPP regarding the frame configuration in the LTE system, as described in Non-Patent Document 1 (Chapter 5), will be explained using Figure 1. Figure 1 is an explanatory diagram showing the configuration of a radio frame used in an LTE communication system. In Figure 1, one radio frame is 10 ms. The radio frame is divided into 10 equally sized subframes. The subframe is divided into two equally sized slots. The first and sixth subframes of each radio frame include a downlink synchronization signal. The synchronization signals include a primary synchronization signal (P-SS) and a secondary synchronization signal (S-SS).

[0005] The decisions made by 3GPP regarding the channel configuration in the LTE system are described in Non-Patent Document 1 (Chapter 5). It is assumed that the same channel configuration as that of a non-CSG cell is used in a CSG (Closed Subscriber Group) cell.

[0006] The Physical Broadcast Channel (PBCH) is a channel for downlink transmission from a base station (hereinafter simply referred to as a "base station") to a communication terminal (hereinafter simply referred to as a "communication terminal") such as a mobile terminal (hereinafter simply referred to as a "mobile terminal"). A BCH transport block is mapped to four subframes in a 40 ms interval. There is no explicit signaling of the 40 ms timing.

[0007] The Physical Control Format Indicator Channel (PCFICH) is a channel for downlink transmission from a base station to a communication terminal. The PCFICH notifies the communication terminal of the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for PDCCHs. The PCFICH is transmitted every subframe.

[0008] The Physical Downlink Control Channel (PDCCH) is a channel for downlink transmission from a base station to a communication terminal. The PDCCH reports resource allocation information for a Downlink Shared Channel (DL-SCH), which is one of the transport channels described below, resource allocation information for a Paging Channel (PCH), which is also one of the transport channels described below, and Hybrid Automatic Repeat reQuest (HARQ) information for the DL-SCH. The PDCCH carries an uplink scheduling grant. The PDCCH carries Acknowledgement (Ack) / Negative Acknowledgement (Nack), which are response signals to uplink transmissions. The PDCCH is also called an L1 / L2 control signal.

[0009] The Physical Downlink Shared Channel (PDSCH) is a channel for downlink transmission from a base station to a communication terminal. A Downlink Shared Channel (DL-SCH), which is a transport channel, and a PCH, which is also a transport channel, are mapped to the PDSCH.

[0010] A physical multicast channel (PMCH) is a channel for downlink transmission from a base station to communication terminals, and a multicast channel (MCH), which is a transport channel, is mapped to the PMCH.

[0011] The Physical Uplink Control Channel (PUCCH) is a channel for uplink transmission from a communication terminal to a base station. The PUCCH carries Ack / Nack, which are response signals to downlink transmissions. The PUCCH also carries CQI (Channel Quality Indicator) reports. CQI is quality information that indicates the quality of received data or the quality of the communication path. The PUCCH also carries Scheduling Requests (SR).

[0012] The Physical Uplink Shared Channel (PUSCH) is a channel for uplink transmission from a communication terminal to a base station. The Uplink Shared Channel (UL-SCH), which is one of the transport channels, is mapped to the PUSCH.

[0013] The Physical Hybrid ARQ Indicator Channel (PHICH) is a channel for downlink transmission from a base station to a communication terminal. The PHICH carries Ack / Nack, which are response signals to uplink transmission. The Physical Random Access Channel (PRACH) is a channel for uplink transmission from a communication terminal to a base station. The PRACH carries a random access preamble.

[0014] Downlink reference signals (RS) are symbols known in LTE communication systems. The following five types of downlink reference signals are defined: Cell-specific Reference Signal (CRS), MBSFN Reference Signal, UE-specific reference signal Demodulation Reference Signal (DM-RS), Positioning Reference Signal (PRS), and Channel State Information Reference Signal (CSI-RS). Measurement of the physical layer of a communication terminal includes measurement of the reference signal received power (RSRP).

[0015] The transport channels described in Non-Patent Document 1 (Chapter 5) will be explained below. Among the downlink transport channels, a broadcast channel (BCH) is broadcast to the entire coverage of the base station (cell). The BCH is mapped to a physical broadcast channel (PBCH).

[0016] Retransmission control using HARQ (Hybrid ARQ) is applied to the Downlink Shared Channel (DL-SCH). DL-SCH can be broadcast to the entire coverage of a base station (cell). DL-SCH supports dynamic or semi-static resource allocation. Semi-static resource allocation is also called persistent scheduling. DL-SCH supports discontinuous reception (DRX) in communication terminals to reduce power consumption of communication terminals. DL-SCH is mapped to the Physical Downlink Shared Channel (PDSCH).

[0017] The Paging Channel (PCH) supports DRX in communication terminals to enable low power consumption in communication terminals. The PCH is required to broadcast to the entire coverage of the base station (cell). The PCH is mapped to physical resources such as the Physical Downlink Shared Channel (PDSCH) that can be dynamically used for traffic.

[0018] The Multicast Channel (MCH) is used for broadcasting to the entire coverage of a base station (cell). The MCH supports SFN combining of MBMS (Multimedia Broadcast Multicast Service) services (MTCH and MCCH) in multi-cell transmission. The MCH supports semi-static resource allocation. The MCH is mapped to the PMCH.

[0019] Among the uplink transport channels, the Uplink Shared Channel (UL-SCH) is subject to retransmission control using HARQ (Hybrid ARQ). The UL-SCH supports dynamic or semi-static resource allocation. The UL-SCH is mapped to the Physical Uplink Shared Channel (PUSCH).

[0020] The Random Access Channel (RACH) is limited to control information. The RACH is subject to collision risk. The RACH is mapped to the Physical Random Access Channel (PRACH).

[0021] We will explain HARQ. HARQ is a technology that improves the communication quality of a transmission channel by combining Automatic Repeat reQuest (ARQ) and Forward Error Correction. HARQ has the advantage that error correction works effectively through retransmission even on transmission channels where communication quality varies. In particular, by combining the reception results of the initial transmission and the retransmission when retransmitting, it is possible to achieve further quality improvement.

[0022] An example of a retransmission method will be explained below. If the receiving side is unable to decode the received data correctly, in other words, if a CRC (Cyclic Redundancy Check) error occurs (CRC=NG), the receiving side will send a "Nack" to the sending side. The sending side, having received the "Nack," will retransmit the data. If the receiving side is able to decode the received data correctly, in other words, if no CRC error occurs (CRC=OK), the receiving side will send an "Ack" to the sending side. The sending side, having received the "Ack," will send the next data.

[0023] The logical channels described in Non-Patent Document 1 (Chapter 6) will be explained below. The Broadcast Control Channel (BCCH) is a downlink channel for broadcast system control information. The BCCH, which is a logical channel, is mapped to the broadcast channel (BCH) or the downlink shared channel (DL-SCH), which are transport channels.

[0024] The Paging Control Channel (PCCH) is a downlink channel for transmitting paging information and changes to system information. The PCCH is used when the network does not know the cell location of the communication terminal. The PCCH, which is a logical channel, is mapped to the Paging Channel (PCH), which is a transport channel.

[0025] A Common Control Channel (CCCH) is a channel for transmission control information between a communication terminal and a base station. CCCH is used when a communication terminal does not have an RRC connection with the network. In the downlink direction, CCCH is mapped to a Downlink Shared Channel (DL-SCH), which is a transport channel. In the uplink direction, CCCH is mapped to an Uplink Shared Channel (UL-SCH), which is a transport channel.

[0026] The Multicast Control Channel (MCCH) is a downlink channel for point-to-multipoint transmission. The MCCH is used to transmit MBMS control information for one or several MTCHs from the network to communication terminals. The MCCH is used only by communication terminals receiving MBMS. The MCCH is mapped to the Multicast Channel (MCH), which is a transport channel.

[0027] A dedicated control channel (DCCH) is a channel that transmits dedicated control information between a communication terminal and a network on a one-to-one basis. The DCCH is used when the communication terminal is in an RRC connection. The DCCH is mapped to an uplink shared channel (UL-SCH) in the uplink and to a downlink shared channel (DL-SCH) in the downlink.

[0028] A Dedicated Traffic Channel (DTCH) is a one-to-one communication channel for transmitting user information to an individual communication terminal. DTCH exists in both uplink and downlink. In uplink, DTCH is mapped to an uplink shared channel (UL-SCH) and in downlink, it is mapped to a downlink shared channel (DL-SCH).

[0029] The Multicast Traffic Channel (MTCH) is a downlink channel for transmitting traffic data from the network to communication terminals. The MTCH is a channel used only by communication terminals receiving MBMS. The MTCH is mapped to the Multicast Channel (MCH).

[0030] CGI stands for Cell Global Identifier. ECGI stands for E-UTRAN Cell Global Identifier. Closed Subscriber Group (CSG) cells are introduced in LTE, LTE-A (Long Term Evolution Advanced) (described below), and UMTS (Universal Mobile Telecommunication System).

[0031] A CSG (Closed Subscriber Group) cell is a cell for which an operator has identified available subscribers (hereinafter referred to as a "specific subscriber cell"). The identified subscribers are permitted to access one or more cells in a PLMN (Public Land Mobile Network). The one or more cells to which the identified subscribers are permitted to access are called "CSG cell(s)." However, there are access restrictions within the PLMN.

[0032] A CSG cell is a part of a PLMN that broadcasts a unique CSG identity (CSG ID) and broadcasts a CSG indication of "TRUE." Members of a pre-registered and authorized subscriber group access the CSG cell using the CSG ID, which is access permission information.

[0033] The CSG ID is broadcast by a CSG cell or cells. There are multiple CSG IDs in an LTE communication system. The CSG ID is used by a communication terminal (UE) to facilitate access by CSG-related members.

[0034] The location of a communication terminal is tracked in units of an area consisting of one or more cells. Location tracking is performed to track the location of the communication terminal even when it is in standby mode and to enable the communication terminal to be called, in other words, to allow the communication terminal to receive calls. The area used for tracking the location of this communication terminal is called a tracking area.

[0035] 3GPP is studying base stations called Home-NodeB (Home-NB; HNB) and Home-eNodeB (Home-eNB; HeNB). HNB in ​​UTRAN and HeNB in ​​E-UTRAN are base stations for access services for homes, businesses, and businesses, for example. Non-Patent Document 2 discloses three different modes of access to HeNB and HNB. Specifically, it discloses an open access mode, a closed access mode, and a hybrid access mode.

[0036] 3GPP is also working on the development of the Long Term Evolution Advanced (LTE-A) standard as Release 10 (see Non-Patent Documents 3 and 4). LTE-A is based on the LTE wireless communication system, and is configured by adding several new technologies to it.

[0037] In the LTE-A system, carrier aggregation (CA) is being considered, which aggregates two or more component carriers (CCs) (also called "aggregation") to support wider frequency bandwidths (transmission bandwidths) up to 100 MHz. CA is described in Non-Patent Document 1.

[0038] When CA is configured, the UE has only one RRC connection with the network (NW). In the RRC connection, one serving cell provides NAS mobility information and security input. This cell is called the primary cell (PCell). In the downlink, the carrier corresponding to the PCell is the downlink primary component carrier (DL PCC). In the uplink, the carrier corresponding to the PCell is the uplink primary component carrier (UL PCC).

[0039] Depending on the UE's capabilities, a secondary cell (SCell) is configured to form a serving cell set together with the PCell. In the downlink, the carrier corresponding to the SCell is the downlink secondary component carrier (DL SCC). In the uplink, the carrier corresponding to the SCell is the uplink secondary component carrier (UL SCC).

[0040] A set of serving cells, which includes one PCell and one or more SCells, is configured for one UE.

[0041] Furthermore, new technologies for LTE-A include wider bandwidth extension and Coordinated Multiple Point transmission and reception (CoMP) technology. CoMP, which is being considered for LTE-A by 3GPP, is described in Non-Patent Document 1.

[0042] Furthermore, in order to handle future massive traffic volumes, 3GPP is considering using small eNBs (hereinafter sometimes referred to as "small-scale base station devices") that configure small cells. For example, technologies are being considered that aim to increase communication capacity by installing a large number of small eNBs and configuring a large number of small cells to improve frequency utilization efficiency. Specifically, there is dual connectivity (abbreviated as DC), in which a UE connects to two eNBs to communicate. DC is described in Non-Patent Document 1.

[0043] Of the eNBs that perform dual connectivity (DC), one may be referred to as a "master eNB (abbreviated as MeNB)" and the other as a "secondary eNB (abbreviated as SeNB)."

[0044] Mobile network traffic volume is on the rise, and communication speeds are also increasing. Once LTE and LTE-A are fully operational, communication speeds are expected to increase even further.

[0045] Furthermore, in response to the increasing sophistication of mobile communications, fifth-generation (hereinafter sometimes referred to as "5G") wireless access systems are being considered, with the goal of launching services after 2020. For example, in Europe, an organization called METIS has compiled requirements for 5G (see Non-Patent Document 5).

[0046] The requirements for a 5G wireless access system are that it will have 1,000 times the system capacity, 100 times the data transmission speed, one-tenth (1 / 10) the data processing delay, and 100 times the number of simultaneous connections of communication terminals compared to an LTE system, while also achieving further reductions in power consumption and lower equipment costs.

[0047] To meet these demands, 3GPP is currently working on 5G standards as Release 15 (see Non-Patent Documents 6 to 17 and 25). 5G wireless technology is called "New Radio Access Technology" ("New Radio" is abbreviated as "NR").

[0048] NR supports various subcarrier spacings, i.e., various numerologies. In NR, regardless of the numerology, one subframe is 1 millisecond and one slot consists of 14 symbols. The number of slots included in one subframe is one in numerologies with a subcarrier spacing of 15 kHz, but increases in proportion to the subcarrier spacing in other numerologies (see Non-Patent Document 13 (TS38.211 v15.0.0)).

[0049] Additionally, 3GPP is studying several new technologies, such as a technology to avoid collisions between the Sounding Reference Signal (SRS) and other channels and signals, and a technology to reduce power consumption by applying BWP (Bandwidth Part) (see Non-Patent Documents 18 to 24).

[0050] In NR, the SRS used for uplink channel sounding is allocated within the last 6 symbols of one slot consisting of 14 symbols. The number of SRS symbols is either 1, 2, or 4 (see Non-Patent Documents 13 and 15). [Prior art documents] [Non-patent literature]

[0051] [Non-Patent Document 1] 3GPP TS 36.300 V14.3.0 [Non-patent document 2] 3GPP S1-083461 [Non-patent document 3] 3GPP TR 36.814 V9.2.0 [Non-patent document 4] 3GPP TR 36.912 V14.0.0 [Non-Patent Document 5] “Scenarios, requirements and KPIs for 5G mobile and wireless system”, ICT-317669-METIS / D1.1 [Non-patent document 6] 3GPP TR 23.799 V14.0.0 [Non-Patent Document 7] 3GPP TR 38.801 V14.0.0 [Non-patent document 8] 3GPP TR 38.802 V14.1.0 [Non-Patent Document 9] 3GPP TR 38.804 V14.0.0 [Non-Patent Document 10] 3GPP TR 38.912 V14.0.0 [Non-Patent Document 11] 3GPP RP-172115 [Non-Patent Document 12] 3GPP TS 37.340 V15.0.0 [Non-Patent Document 13] 3GPP TS 38.211 V15.0.0 [Non-Patent Document 14] 3GPP TS 38.213 V15.0.0 [Non-Patent Document 15] 3GPP TS 38.214 V15.0.0 [Non-Patent Document 16] 3GPP TS 38.300 V15.0.0 [Non-Patent Document 17] 3GPP TS 38.321 V15.0.0 [Non-Patent Document 18] 3GPP R1-1802830 [Non-Patent Document 19] 3GPP R1-1801741 [Non-Patent Document 20] 3GPP R1-1801732 [Non-Patent Document 21] 3GPP R1-1800935 [Non-Patent Document 22] 3GPP R1-1715277 [Non-Patent Document 23] 3GPP R1-1720349 [Non-Patent Document 24] 3GPP R1-1800679 [Non-Patent Document 25] 3GPP TS 38.212 V15.0.0 Summary of the Invention [Problem to be solved by the invention]

[0052] In NR, the number of symbols that can transmit SRS has been expanded from the last symbol in LTE to the last six symbols, which may result in collisions with other uplink channels, such as PUSCH and PUCCH. As a result, discrepancies in SRS settings may occur between the UE and the base station. This can cause malfunctions in communication systems using NR, making it impossible to ensure reliable communications. Furthermore, SRS uses the uplink communication resources of other UEs, causing mutual interference with the uplink communications of other UEs. As a result, it becomes impossible to ensure the reliability of the UE's SRS transmission and the uplink communications of other UEs.

[0053] Furthermore, in NR, in order to reduce the power consumption of UEs, a BWP (Bandwidth Part) is applied, which allows scheduling of a portion of the frequency bands of uplink and downlink carriers. However, since there is no established method for measuring channel conditions in bands of carrier frequency bands that are not set as BWPs, UEs and base stations cannot properly measure channel conditions in those bands. This causes a problem in that the reliability of communication between UEs and base stations cannot be ensured.

[0054] In view of the above problems, one of the objects of the present invention is to provide a highly reliable communication system in NR. [Means for solving the problem]

[0055] According to the present invention, for example, there is provided a user equipment in a communication system including a plurality of user equipments each transmitting a sounding reference signal (SRS) and a base station communicating wirelessly with the plurality of user equipments, the user equipment receiving from the base station configuration information regarding radio resources of the sounding reference signal allocated to other user equipments.

[0056] According to the present invention, for example, there is provided a base station in a communication system including a plurality of user devices each transmitting a sounding reference signal (SRS) and a base station that wirelessly communicates with the plurality of user devices, the base station notifying one user device of configuration information regarding radio resources of the sounding reference signal allocated to other user devices.

[0057] According to the present invention, for example, there is provided a communication system including a plurality of user devices each transmitting a sounding reference signal (SRS) and a base station communicating wirelessly with the plurality of user devices, wherein the base station notifies one user device of configuration information regarding radio resources for the sounding reference signal allocated to other user devices. [Effects of the Invention]

[0058] According to the present invention, a highly reliable communication system and the like can be provided.

[0059] The objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0060] [Figure 1] FIG. 1 is an explanatory diagram showing the configuration of a radio frame used in an LTE communication system. [Figure 2] 1 is a block diagram showing the overall configuration of an LTE communication system 200 being discussed in 3GPP. [Figure 3] FIG. 3 is a block diagram showing the configuration of a mobile terminal 202 shown in FIG. [Figure 4] FIG. 3 is a block diagram showing the configuration of a base station 203 shown in FIG. [Figure 5] FIG. 2 is a block diagram illustrating the configuration of an MME. [Figure 6] 1 is a flowchart showing an outline of operations from cell search to standby operation performed by a communication terminal (UE) in an LTE communication system. [Figure 7] FIG. 1 is a diagram illustrating the concept of a cell configuration when macro eNBs and small eNBs are mixed. [Figure 8] FIG. 10 is a diagram illustrating PUSCH transmission before and after an SRS of another UE according to the first embodiment. [Figure 9] FIG. 10 is a diagram illustrating an example in which PUSCH transmission is stopped in a range from the earliest symbol to the latest symbol of an SRS transmission symbol group, according to the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example in which PUSCH transmission is stopped only at an SRS transmission symbol notified to a UE, according to the first embodiment. [Figure 11] FIG. 10 is a diagram illustrating an example in which PUSCH transmission is performed outside the PRB range of an SRS, according to the first embodiment. [Figure 12] FIG. 10 is a diagram illustrating an example in which PUSCH transmission is performed outside a PRB range and within a PRB range of an SRS, according to the first embodiment. [Figure 13] FIG. 10 is a diagram illustrating an example in which a base station notifies a UE of information related to SRS transmission from other UEs for each slot, in accordance with the first embodiment. [Figure 14] FIG. 10 is a diagram showing an example of adding a DMRS before and after an SRS transmission from another UE, according to the first embodiment. [Figure 15] FIG. 10 is a diagram showing an example of adding a PTRS after an SRS is transmitted from another UE in the first embodiment. [Figure 16] FIG. 10 illustrates an example of a first modification of the first embodiment in which an SRS is transmitted from an SRS-transmitting UE outside the symbols and frequency bands allocated to a PUSCH transmitted by the PUSCH-transmitting UE. [Figure 17] FIG. 10 is a diagram illustrating an example of a first modification of the first embodiment, in which SRS transmission from an SRS-transmitting UE is performed with varying comb density in a symbol and frequency band to which a PUSCH transmitted by the PUSCH-transmitting UE is allocated. [Figure 18]FIG. 10 illustrates an example of a first modification of the first embodiment in which SRS transmission from an SRS-transmitting UE is not performed in a symbol to which a PUSCH transmitted by a PUSCH-transmitting UE is allocated. [Figure 19] FIG. 10 is a diagram illustrating an example of shifting SRS transmission symbols only in the PUSCH allocation band, in accordance with a first modification of the first embodiment. [Figure 20] FIG. 10 is a diagram illustrating an example of shifting the entire SRS transmission symbol, according to the first modification of the first embodiment. [Figure 21] FIG. 10 is a diagram illustrating an example of shifting SRS transmission symbols to different slots only in the PUSCH allocation band, in accordance with a first modification of the first embodiment. [Figure 22] FIG. 10 is a diagram illustrating an example of shifting all SRS transmission symbols to different slots, in accordance with a first modification of the first embodiment. [Figure 23] FIG. 10 is a diagram illustrating an operation in a case where PUSCH transmission and SRS transmission from a UE are allocated to the same slot, according to the second modification of the first embodiment. [Figure 24] FIG. 11 is a diagram illustrating an operation of avoiding collision between SRS and PUSCH in response to a notification of a collision avoidance instruction from a base station, according to a third modification of the first embodiment. [Figure 25] FIG. 11 is a diagram showing an operation of avoiding collision between SRS and PUCCH in response to a notification of a collision avoidance instruction from a base station, according to a third modification of the first embodiment. [Figure 26] FIG. 11 is a diagram showing another example of the operation of avoiding collision between SRS and PUCCH in response to a notification of a collision avoidance instruction from a base station, in accordance with the third modification of the first embodiment. [Figure 27] FIG. 11 is a diagram illustrating an example of configuring SRS transmission in a measurement gap using semi-static signaling according to the second embodiment. [Figure 28] FIG. 11 is a diagram illustrating an example of configuring SRS transmission in a measurement gap using dynamic signaling according to the second embodiment. [Figure 29]FIG. 11 is a diagram illustrating an example of setting SRS transmission by providing a gap for UL transmission, according to the second embodiment. [Figure 30] FIG. 11 is a diagram illustrating another example of setting SRS transmission by providing a gap for UL transmission, according to the second embodiment. [Figure 31] FIG. 11 is a diagram showing a specific example of setting SRS transmission by providing a gap for UL transmission, according to the second embodiment. [Figure 32] FIG. 11 is a diagram showing a specific example of a measurement gap only in DL according to the second embodiment. [Figure 33] FIG. 11 is a diagram illustrating an example of setting a plurality of measurement gaps in TDD according to the second embodiment. [Figure 34] FIG. 11 is a diagram illustrating another example of setting a plurality of measurement gaps in TDD according to the second embodiment. [Figure 35] FIG. 11 is a diagram showing an example of how to provide a sounding BWP according to the third embodiment. [Figure 36] FIG. 13 is a diagram illustrating a problem that occurs when the BWP used for a low-latency PUSCH and a normal-latency PUSCH differs, in accordance with the fourth embodiment. [Figure 37] FIG. 11 is a diagram illustrating a problem in PUSCH scheduling when the numerology differs between downlink and uplink in accordance with a fifth embodiment. [Figure 38] FIG. 13 is a diagram illustrating PUSCH scheduling by a PDCCH located in the middle of a slot according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0061] Embodiment 1 Fig. 2 is a block diagram showing the overall configuration of an LTE communication system 200 being discussed in 3GPP. Fig. 2 will now be described. The radio access network is called E-UTRAN (Evolved Universal Terrestrial Radio Access Network) 201. A mobile terminal device (hereinafter referred to as "mobile terminal (User Equipment: UE)") 202, which is a communication terminal device, is capable of wireless communication with a base station device (hereinafter referred to as "base station (E-UTRAN NodeB: eNB)") 203, and transmits and receives signals via wireless communication.

[0062] Here, the term "communication terminal device" includes not only mobile terminal devices such as mobile cell phone terminal devices, but also stationary devices such as sensors. In the following description, the term "communication terminal device" may be simply referred to as a "communication terminal."

[0063] If control protocols for mobile terminals 202, such as RRC (Radio Resource Control), and user planes (hereinafter sometimes referred to as U-Planes), such as PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and PHY (Physical layer), terminate at base stations 203, E-UTRAN is composed of one or more base stations 203.

[0064] The control protocol RRC (Radio Resource Control) between the mobile terminal 202 and the base station 203 performs broadcasting, paging, RRC connection management, etc. The states of the base station 203 and the mobile terminal 202 in RRC include RRC_IDLE and RRC_CONNECTED.

[0065] In RRC_IDLE, PLMN (Public Land Mobile Network) selection, system information (SI) broadcast, paging, cell reselection, mobility, etc. are performed. In RRC_CONNECTED, the mobile terminal has an RRC connection and can transmit and receive data with the network. In addition, in RRC_CONNECTED, handover (HO), measurement of neighbor cells, etc. are performed.

[0066] The base stations 203 are classified into eNBs 207 and Home-eNBs 206. The communication system 200 includes an eNB group 203-1 including a plurality of eNBs 207, and a Home-eNB group 203-2 including a plurality of Home-eNBs 206. A system configured from an EPC (Evolved Packet Core) core network and an E-UTRAN 201 radio access network is called an EPS (Evolved Packet System). The EPC core network and the E-UTRAN 201 radio access network may be collectively referred to as a "network."

[0067] The eNB 207 is connected to a Mobility Management Entity (MME), or a Serving Gateway (S-GW), or an MME / S-GW unit (hereinafter sometimes referred to as an "MME unit") 204 including an MME and an S-GW via an S1 interface, and control information is communicated between the eNB 207 and the MME unit 204. Multiple MME units 204 may be connected to one eNB 207. The eNBs 207 are connected to each other via an X2 interface, and control information is communicated between the eNBs 207.

[0068] The Home-eNB 206 is connected to the MME unit 204 via an S1 interface, and control information is communicated between the Home-eNB 206 and the MME unit 204. A plurality of Home-eNBs 206 are connected to one MME unit 204. Alternatively, the Home-eNB 206 is connected to the MME unit 204 via a Home-eNB GateWay (HeNBGW) 205. The Home-eNB 206 and the HeNBGW 205 are connected via an S1 interface, and the HeNBGW 205 and the MME unit 204 are connected via the S1 interface.

[0069] One or more Home-eNBs 206 are connected to one HeNBGW 205, and information is communicated through an S1 interface. The HeNBGW 205 is connected to one or more MME units 204, and information is communicated through an S1 interface.

[0070] The MME unit 204 and the HeNBGW 205 are upper devices, specifically upper nodes, and control connections between the eNB 207 and the Home-eNB 206, which are base stations, and the mobile terminal (UE) 202. The MME unit 204 constitutes the EPC, which is a core network. The base station 203 and the HeNBGW 205 constitute the E-UTRAN 201.

[0071] Furthermore, 3GPP is considering the following configuration: The X2 interface between Home-eNBs 206 is supported. That is, Home-eNBs 206 are connected via the X2 interface, and control information is communicated between the Home-eNBs 206. From the MME unit 204, HeNBGW 205 appears as Home-eNB 206. From the Home-eNB 206, HeNBGW 205 appears as MME unit 204.

[0072] In either case where the Home-eNB 206 is connected to the MME unit 204 via the HeNBGW 205 or where the Home-eNB 206 is connected directly to the MME unit 204, the interface between the Home-eNB 206 and the MME unit 204 is the same, that is, the S1 interface.

[0073] Base station 203 may configure one cell or multiple cells. Each cell has a predetermined range as coverage, which is the range within which communication with mobile terminal 202 is possible, and performs wireless communication with mobile terminal 202 within the coverage. When one base station 203 configures multiple cells, each cell is configured to be able to communicate with mobile terminal 202.

[0074] FIG. 3 is a block diagram showing the configuration of mobile terminal 202 shown in FIG. 2. The transmission process of mobile terminal 202 shown in FIG. 3 will be described. First, control data from protocol processing unit 301 and user data from application unit 302 are stored in transmission data buffer unit 303. The data stored in transmission data buffer unit 303 is passed to encoder unit 304, where it is subjected to encoding processes such as error correction. Some data may be output directly from transmission data buffer unit 303 to modulation unit 305 without being encoded. The data encoded by encoder unit 304 is modulated by modulation unit 305. The modulated data is converted into a baseband signal, and then output to frequency conversion unit 306, where it is converted into a radio transmission frequency. The transmission signal is then transmitted from antenna 307 to base station 203.

[0075] Furthermore, the reception process of the mobile terminal 202 is performed as follows. A radio signal from the base station 203 is received by the antenna 307. The received signal is converted from a radio reception frequency to a baseband signal by the frequency conversion unit 306, and demodulated by the demodulation unit 308. The demodulated data is passed to the decoder unit 309, where decoding processes such as error correction are performed. Of the decoded data, the control data is passed to the protocol processing unit 301, and the user data is passed to the application unit 302. A series of processes of the mobile terminal 202 is controlled by the control unit 310. Therefore, although the control unit 310 is omitted in FIG. 3, it is connected to each of the units 301 to 309.

[0076] Figure 4 is a block diagram showing the configuration of the base station 203 shown in Figure 2. The transmission processing of the base station 203 shown in Figure 4 will be described. The EPC communication unit 401 transmits and receives data between the base station 203 and the EPC (MME unit 204, etc.), the HeNBGW 205, etc. The other base station communication unit 402 transmits and receives data with other base stations. The EPC communication unit 401 and the other base station communication unit 402 each exchange information with a protocol processing unit 403. Control data from the protocol processing unit 403, and user data and control data from the EPC communication unit 401 and the other base station communication unit 402 are stored in a transmission data buffer unit 404.

[0077] The data stored in the transmission data buffer unit 404 is passed to the encoder unit 405, where it undergoes encoding processes such as error correction. Some data may be output directly from the transmission data buffer unit 404 to the modulator unit 406 without undergoing encoding processes. The encoded data is modulated by the modulator unit 406. The modulated data is converted into a baseband signal, and then output to the frequency converter 407, where it is converted into a radio transmission frequency. The transmission signal is then transmitted from the antenna 408 to one or more mobile terminals 202.

[0078] The reception process of the base station 203 is performed as follows: A radio signal from one or more mobile terminals 202 is received by an antenna 408. The received signal is converted from a radio reception frequency to a baseband signal by a frequency conversion unit 407, and demodulated by a demodulation unit 409. The demodulated data is passed to a decoder unit 410, where decoding processes such as error correction are performed. Of the decoded data, control data is passed to a protocol processing unit 403 or an EPC communication unit 401 or an other base station communication unit 402, and user data is passed to the EPC communication unit 401 and the other base station communication unit 402. A series of processes of the base station 203 is controlled by a control unit 411. Therefore, although the control unit 411 is omitted in FIG. 4, it is connected to each of the units 401 to 410.

[0079] 5 is a block diagram showing the configuration of an MME. FIG. 5 shows the configuration of an MME 204a included in the MME unit 204 shown in FIG. 2 described above. A PDN GW communication unit 501 transmits and receives data between the MME 204a and a PDN GW. A base station communication unit 502 transmits and receives data via the S1 interface between the MME 204a and a base station 203. If the data received from the PDN GW is user data, the user data is passed from the PDN GW communication unit 501 to the base station communication unit 502 via a user plane communication unit 503, and transmitted to one or more base stations 203. If the data received from the base station 203 is user data, the user data is passed from the base station communication unit 502 to the PDN GW communication unit 501 via the user plane communication unit 503, and transmitted to the PDN GW.

[0080] If the data received from the PDN GW is control data, the control data is passed from the PDN GW communication unit 501 to the control plane control unit 505. If the data received from the base station 203 is control data, the control data is passed from the base station communication unit 502 to the control plane control unit 505.

[0081] The HeNBGW communication unit 504 is provided when a HeNBGW 205 is present, and transmits and receives data via an interface (IF) between the MME 204a and the HeNBGW 205 depending on the information type. Control data received from the HeNBGW communication unit 504 is passed from the HeNBGW communication unit 504 to the control plane control unit 505. The result of processing in the control plane control unit 505 is transmitted to the PDN GW via the PDN GW communication unit 501. In addition, the result of processing in the control plane control unit 505 is transmitted to one or more base stations 203 by the S1 interface via the base station communication unit 502, and is also transmitted to one or more HeNBGWs 205 via the HeNBGW communication unit 504.

[0082] The control plane control unit 505 includes a NAS security unit 505-1, an SAE bearer control unit 505-2, an idle state mobility management unit 505-3, etc., and performs overall processing for the control plane (hereinafter sometimes referred to as the C-Plane). The NAS security unit 505-1 performs security for NAS (Non-Access Stratum) messages, etc. The SAE bearer control unit 505-2 performs management of SAE (System Architecture Evolution) bearers, etc. The idle state mobility management unit 505-3 performs mobility management in the idle state (also referred to as the LTE-IDLE state or simply idle), generation and control of paging signals in the idle state, addition, deletion, update, and search of tracking areas for one or more mobile terminals 202 under its control, tracking area list management, etc.

[0083] The MME 204a distributes paging signals to one or more base stations 203. The MME 204a also performs mobility control in an idle state. The MME 204a manages a tracking area list when the mobile terminal is in an idle state and an active state. The MME 204a initiates a paging protocol by transmitting a paging message to cells belonging to a tracking area in which the UE is registered. The idle state mobility management unit 505-3 may manage the CSG, CSG ID, and whitelist of the Home-eNB 206 connected to the MME 204a.

[0084] Next, an example of a cell search method in a communication system is shown. Fig. 6 is a flowchart showing an outline of the process from cell search to standby operation performed by a communication terminal (UE) in an LTE communication system. When the communication terminal starts a cell search, in step ST601, it synchronizes slot timing and frame timing using a primary synchronization signal (P-SS) and a secondary synchronization signal (S-SS) transmitted from a surrounding base station.

[0085] P-SS and S-SS are collectively called the Synchronization Signal (SS). The Synchronization Signal (SS) is assigned a synchronization code that corresponds one-to-one to the PCI assigned to each cell. 504 different PCIs are being considered. These 504 different PCIs are used to achieve synchronization and to detect (identify) the PCI of the synchronized cell.

[0086] Next, in step ST602, for the synchronized cell, a cell-specific reference signal (CRS), which is a reference signal (RS) transmitted from the base station for each cell, is detected and the RS received power (Reference Signal Received Power: RSRP) is measured. The RS uses a code that has a one-to-one correspondence with the PCI. By correlating with this code, it is possible to separate the cell from other cells. By deriving the code for the RS of the cell from the PCI identified in step ST601, it is possible to detect the RS and measure the RS received power.

[0087] Next, in step ST603, the cell with the best RS reception quality, for example, the cell with the highest RS reception power, that is, the best cell, is selected from one or more cells detected up to step ST602.

[0088] Next, in step ST604, the PBCH of the best cell is received to obtain the BCCH, which is broadcast information. A MIB (Master Information Block), which includes cell configuration information, is mapped to the BCCH on the PBCH. Therefore, the MIB can be obtained by receiving the PBCH and obtaining the BCCH. Examples of MIB information include the DL (downlink) system bandwidth (also called transmission bandwidth configuration: dl-bandwidth), the number of transmitting antennas, and the SFN (System Frame Number).

[0089] Next, in step ST605, the DL-SCH of the cell is received based on the cell configuration information in the MIB, and SIB (System Information Block) 1 is obtained from the broadcast information BCCH. SIB 1 includes information on access to the cell, information on cell selection, and scheduling information for other SIBs (SIBk; k is an integer greater than or equal to 2). SIB 1 also includes a tracking area code (TAC).

[0090] Next, in step ST606, the communication terminal compares the TAC of the SIB1 received in step ST605 with the TAC portion of the tracking area identity (TAI) in the tracking area list that the communication terminal already holds. The tracking area list is also called a TAI list. The TAI is identification information for identifying a tracking area, and is composed of an MCC (Mobile Country Code), an MNC (Mobile Network Code), and a TAC (Tracking Area Code). The MCC is a country code. The MNC is a network code. The TAC is a tracking area code number.

[0091] If the comparison in step ST606 shows that the TAC received in step ST605 is the same as the TAC included in the tracking area list, the communication terminal enters standby mode in the cell. If the comparison shows that the TAC received in step ST605 is not included in the tracking area list, the communication terminal requests a core network (EPC) including an MME, etc., to change the tracking area in order to perform a Tracking Area Update (TAU) through the cell.

[0092] An apparatus constituting a core network (hereinafter sometimes referred to as a "core network side apparatus") updates the tracking area list based on the identification number (e.g., UE-ID) of the communication terminal sent from the communication terminal together with a TAU request signal. The core network side apparatus transmits the updated tracking area list to the communication terminal. The communication terminal rewrites (updates) the TAC list held by the communication terminal based on the received tracking area list. Thereafter, the communication terminal enters standby operation in the cell.

[0093] The widespread use of smartphones and tablet devices has led to an explosive increase in cellular wireless communication traffic, raising concerns about a shortage of wireless resources worldwide. In response to this, efforts are being made to develop small cells and promote spatial separation in order to improve frequency utilization efficiency.

[0094] In a conventional cell configuration, a cell configured by an eNB has a relatively wide coverage area. Conventionally, a cell is configured so that a certain area is covered by the relatively wide coverage areas of multiple cells configured by multiple eNBs.

[0095] In the case of small cell configuration, a cell configured by an eNB has a narrower coverage area than a cell configured by a conventional eNB. Therefore, as in the past, a larger number of small cell configuration eNBs are required to cover a certain area compared to conventional eNBs.

[0096] In the following description, a cell with a relatively large coverage, such as a cell configured by a conventional eNB, is referred to as a "macro cell," and an eNB that configures the macro cell is referred to as a "macro eNB." Also, a cell with a relatively small coverage, such as a cell configured as a small cell, is referred to as a "small cell," and an eNB that configures the small cell is referred to as a "small eNB."

[0097] The macro eNB may be, for example, a "Wide Area Base Station" as described in Non-Patent Document 7.

[0098] The small eNB may be, for example, a low-power node, a local area node, a hotspot, etc. Also, the small eNB may be a pico eNB constituting a pico cell, a femto eNB constituting a femto cell, a HeNB, a remote radio head (RRH), a remote radio unit (RRU), a remote radio equipment (RRE), or a relay node (RN). Also, the small eNB may be a "local area base station" or a "home base station" as described in Non-Patent Document 7.

[0099] 7 is a diagram showing the concept of a cell configuration when macro eNBs and small eNBs are mixed. A macro cell configured by a macro eNB has a relatively wide coverage area 701. A small cell configured by a small eNB has a coverage area 702 that is smaller than the coverage area 701 of the macro eNB (macro cell).

[0100] When multiple eNBs are mixed, the coverage of a cell configured by one eNB may be included in the coverage of a cell configured by another eNB. In the cell configuration shown in Figure 7, as indicated by reference numerals "704" and "705," the coverage 702 of a small cell configured by a small eNB may be included in the coverage 701 of a macro cell configured by a macro eNB.

[0101] Also, as indicated by reference numeral "705," the coverage of multiple, for example, two small cells 702 may be included within the coverage of one macro cell 701. A mobile terminal (UE) 703 is included, for example, within the coverage of a small cell 702 and communicates via the small cell.

[0102] Furthermore, in the cell configuration shown in FIG. 7, there may be cases where coverage 701 of a macro cell configured by a macro eNB and coverage 702 of a small cell configured by a small eNB overlap in a complex manner, as indicated by reference numeral "706."

[0103] Also, as indicated by reference numeral "707," there may be cases where coverage 701 of a macro cell configured by a macro eNB and coverage 702 of a small cell configured by a small eNB do not overlap.

[0104] Furthermore, as indicated by reference numeral "708," there may be cases where the coverage 702 of multiple small cells formed by multiple small eNBs is formed within the coverage 701 of one macro cell formed by one macro eNB.

[0105] The base station allocates the PUSCH before or after the SRS transmitted by the same UE. The base station notifies the UE of information including the PUSCH allocation start symbol number and the number of allocated symbols. This notification may be notified using L1 / L2 signaling or RRC signaling.

[0106] However, there is no discussion about the allocation of PUSCH when a UE to which a PUSCH is scheduled (hereinafter, sometimes referred to as a PUSCH-transmitting UE) is different from a UE that transmits an SRS (hereinafter, sometimes referred to as an SRS-transmitting UE). Therefore, the base station cannot appropriately schedule PUSCH for PUSCH-transmitting UE, which results in a problem such as the PUSCH and SRS interfering with each other because the PUSCH and SRS are allocated to the same time and frequency resources.

[0107] A solution to the above problem is disclosed. The above allocation is applied when the SRS transmitting UE and the PUSCH transmitting UE are different from each other. There may be multiple SRS transmitting UEs. The base station may allocate PUSCH transmission symbols to a PUSCH transmitting UE before or after a group of symbols in which SRS is transmitted by one or more UEs other than the UE.

[0108] The symbol group may be a set of SRS symbols transmitted by one or more SRS-transmitting UEs. The symbols constituting the symbol group may be discrete. For example, a symbol to which no SRS is assigned may exist between SRS symbols transmitted by one or more SRS-transmitting UEs. This allows, for example, a base station to flexibly assign SRS symbols. When a base station assigns PUSCH transmission symbols to PUSCH-transmitting UEs, "before a symbol group" may mean before the earliest symbol of the symbols constituting the symbol group. "After a symbol group" may mean after the latest symbol of the symbols constituting the symbol group.

[0109] As another example, the symbols constituting the symbol group may be consecutive, which may be specified by a standard or determined by a base station, which may facilitate scheduling in a communication system, for example.

[0110] However, by arranging the PUSCH before or after the SRS symbol or SRS symbol group, the number of symbols in which the PUSCH can be arranged within a slot decreases, resulting in a problem of a decrease in the transmission rate of the PUSCH. In addition, when SRS transmitted by other UEs, particularly multiple UEs, is allocated to the frequency resource in which the UE transmits its PUSCH, the number of symbols in which the PUSCH of the UE can be arranged further decreases, resulting in a problem of a further decrease in the PUSCH transmission rate of the UE.

[0111] Solutions to the aforementioned problems are disclosed below.

[0112] A UE is enabled to transmit a PUSCH both before and after an SRS. The SRS may be an SRS transmitted by the UE itself or an SRS transmitted by another UE. The UE may stop transmitting a PUSCH, a DMRS associated with the PUSCH, or a Phase Tracking Reference Signal (PTRS) associated with the PUSCH in the symbol in which the SRS is transmitted. Hereinafter, unless otherwise specified, the method for a PUSCH may be similarly applied to a DMRS associated with a PUSCH and a PTRS associated with a PUSCH.

[0113] Fig. 8 is a diagram showing PUSCH transmissions before and after the SRS of other UEs. Fig. 8 shows an example in which UE#1 transmits a PUSCH and UE#2 transmits an SRS. In Fig. 8, the horizontal axis represents the time axis and the vertical axis represents the frequency axis.

[0114] In the example shown in Figure 8, the SRS 805 transmitted by UE #2 is allocated to the 9th symbol, with the start of the slot being the 0th symbol. Similarly, the start of the slot is also designated as the 0th symbol below. The frequency band occupied by the SRS is allocated so as to include the frequency band allocated to PUSCH transmission of UE #1. In the example shown in Figure 8, the DMRS 806 associated with the PUSCH of UE #1 is allocated to the 2nd symbol, and the PTRS 807 associated with the PUSCH is allocated to the subcarrier with the lowest frequency in the frequency band occupied by the PUSCH.

[0115] 8, UE#1 may transmit PUSCH 810 and PUSCH 811 on both sides of the ninth symbol to which the SRS of UE#2 is allocated. UE#1 may stop transmitting PUSCH in the ninth symbol.

[0116] The base station may notify a PUSCH-transmitting UE of the SRS configuration allocated to the UEs in the cell to which the UE belongs in advance. The SRS configuration in the notification is performed in units of symbols along the time axis and in units of physical resource blocks (PRBs) along the frequency axis. Using the notification, the PUSCH-transmitting UE stops PUSCH transmission in symbols where other UEs transmit SRS.

[0117] Although the example described above shows that PUSCH transmission is stopped in the symbol in which another UE transmits an SRS, the above method may also be applied to the SRS transmitted by the UE itself. That is, the UE may transmit PUSCHs before and after the SRS transmitted by the UE itself. This makes it possible to improve the transmission rate of the PUSCH.

[0118] When applying the above-described method, the following problems arise. That is, the above-described signaling from the base station to the UE does not explicitly indicate to which temporal behavior of the SRS the signaling is applied. In particular, it is not clear whether the above-described signaling is applied to semi-persistent SRS and aperiodic SRS, which may not actually be transmitted. For this reason, a PUSCH-transmitting UE cannot transmit a PUSCH while avoiding the semi-persistent SRS and aperiodic SRS transmitted from other UEs. As a result, interference may occur between the semi-persistent SRS and aperiodic SRS transmitted by other UEs and the PUSCH transmitted by the UE itself. This causes problems such as inaccurate sounding at the base station and reduced PUSCH reliability.

[0119] Furthermore, the amount of signaling increases when the base station notifies the UE of the SRS settings of all UEs in the cell.

[0120] Furthermore, if a PUSCH transmitting UE stops transmitting the PUSCH while another UE is transmitting an SRS and resumes transmitting the PUSCH after the other UE transmits the SRS, phase and / or amplitude drift may occur in the PUSCH transmission after the resumption. Furthermore, since the PTRS transmission associated with the PUSCH is stopped in response to the SRS transmission from the other UE, for example, when the PTRS is transmitted at a rate of one symbol per multiple symbols, compensation for PUSCH phase noise in symbols surrounding the SRS transmission symbol from the other UE becomes impossible. As a result, a problem occurs in which the demodulation characteristics of the PUSCH at the base station deteriorate.

[0121] Solutions to the aforementioned problems are disclosed below.

[0122] A base station notifies a UE in advance of SRS transmission resource candidates configured for the UE under its control. The base station may notify the UE individually. The notification may be performed semi-statically. For example, the notification may be performed using RRC signaling or MAC signaling. The SRS transmission resource candidates may include, for example, all resource configurations configured for aperiodic SRS, resource configurations configured for semi-persistent SRS, or resource configurations for periodic SRS. A UE may use the notification to stop PUSCH transmission in the SRS transmission resource candidates of other UEs. For example, a UE may stop PUSCH transmission every slot in all resources configured for aperiodic SRS. As another example, a UE may stop PUSCH transmission in resources configured for semi-persistent SRS, regardless of whether transmission of the SRS is activated. This may prevent interference between the aperiodic SRS or semi-persistent SRS of other UEs and the PUSCH transmission of the UE itself.

[0123] The following items (1) to (12) are disclosed as information about SRS transmission resource candidates semi-statically notified from the base station to the UE.

[0124] (1) Information that identifies the SRS settings.

[0125] (2) Type of SRS setting.

[0126] (3) Information about SRS transmission symbols.

[0127] (4) Information about SRS transmission frequencies.

[0128] (5) Information about the sequence of the SRS.

[0129] (6) Information about SRS Comb settings.

[0130] (7)SRS antenna port.

[0131] (8) SRS numerology.

[0132] (9) Information about the SRS transmission period and offset.

[0133] (10) Information on whether PUSCH transmission is possible. Examples of this information include the following (10-1) to (10-6).

[0134] (10-1) Information on whether or not PUSCH transmission is possible before the earliest symbol among the SRS transmission symbols in the slot.

[0135] (10-2) Information on whether or not PUSCH transmission is possible after the latest symbol among the SRS transmission symbols in the slot.

[0136] (10-3) Information regarding whether PUSCH transmission is possible within the range from the earliest symbol to the latest symbol of the SRS transmission symbol group within a slot.

[0137] (10-4) Information regarding whether PUSCH transmission is possible in the set SRS transmission symbol.

[0138] (10-5) Information regarding whether PUSCH transmission is possible within the set SRS transmission frequency resource within the set SRS transmission symbol.

[0139] (10-6) A combination of the above (10-1) to (10-5).

[0140] (11) Information about the beam used in SRS transmission.

[0141] (12) A combination of (1) to (11) above.

[0142] The information related to (1) above may include, for example, information about the UE (e.g., a UE identifier) ​​or information about a resource configuration number for aperiodic SRS. The information related to (1) above may be uniquely assigned within one UE or may be uniquely assigned within multiple UEs, for example, all UEs in a cell.

[0143] The above (1) enables, for example, a base station to notify a UE of information related to changes in the SRS settings of the UE within the cell with a small amount of information, thereby reducing the amount of signaling from the base station to the UE.

[0144] The above-mentioned (2) may be, for example, information indicating whether the SRS is periodic, semi-persistent, or aperiodic. As another example, it may be information indicating a use case of the SRS. It may be information combining both of the above. This makes it possible to flexibly set whether to transmit a PUSCH in a communication system depending on whether the SRS is periodic, semi-persistent, or aperiodic, or depending on the use case of the SRS.

[0145] The above-mentioned (3) may be, for example, any one of the SRS transmission start symbol, the number of SRS transmission symbols, and the SRS transmission end symbol, or may be a combination of two or more of the above information.

[0146] Another example of the above (3) may be information about an SRS transmission symbol group. For example, the information may be information indicating a range from the earliest symbol to the latest symbol in the SRS transmission symbol group, such as the earliest symbol, the latest symbol, or the number of symbols from the earliest symbol to the latest symbol, or a combination of the above information. As another example, a bitmap may be used. In the bitmap, each symbol in the slot may be associated with a bit constituting the bitmap. This makes it possible to notify information about multiple SRS configurations with a small amount of information. The above-mentioned multiple SRS configurations may be, for example, SRS transmitted from one UE or SRS transmitted from multiple UEs.

[0147] The above (4) may be, for example, information indicating a range of PRB numbers of a transmission SRS. The information may include, for example, the first PRB number, the last PRB number, and the number of PRBs from the first to the last of the transmission SRS within the carrier of the cell used by the UE. As another example, the information may include information indicating a range of PRB numbers within a BWP (Bandwidth Part) in a PUSCH-transmitting UE, such as the first PRB number, the last PRB number, and the number of PRBs from the first to the last of the transmission SRS within the BWP. This makes it possible to reduce, for example, the amount of processing in a PUSCH-transmitting UE.

[0148] The above (4) may include information about frequency hopping of the SRS. This allows, for example, a PUSCH-transmitting UE to transmit the PUSCH by avoiding the time and / or frequency resources of the SRS even when the SRS is frequency hopping. As a result, for example, it is possible to reduce interference between the PUSCH and the SRS.

[0149] In the above (4), the information indicating the range of PRB numbers may be the number of PRBs that is the setting resolution of the SRS, for example, information in units of 4 PRBs. This makes it possible to reduce the amount of signaling required for the notification from the base station to the UE.

[0150] The above (5) may be, for example, information about a cyclic shift (CS) or information about a root sequence. The information about the CS may be, for example, the CS of the SRS itself, or may include information about CS hopping. This allows, for example, the base station to notify the UE that transmits the PUSCH of signaling with the same content as the SRS transmission setting content for the SRS-transmitting UE. As a result, for example, it is possible to reduce the amount of processing in the base station.

[0151] The above (6) may include, for example, information about the spacing of the comb of the SRS, or may include information about the offset of the comb of the SRS, i.e., the offset of the RE (Resource Element) to which the SRS is allocated. Using this information, the UE may allocate a PUSCH in the same symbol as the SRS, avoiding the RE allocated to the SRS. This may improve, for example, the transmission capacity of the PUSCH.

[0152] The above (7) may include, for example, information about the antenna port number to which the SRS is to be transmitted. The UE may transmit a PUSCH from an antenna port other than the antenna port in the same time and / or frequency resource as the SRS. This may, for example, improve the transmission capacity of the PUSCH.

[0153] The above (8) may include, for example, information about the numerology of the SRS. The PUSCH transmitting UE may use the information about the numerology to derive at which symbol number of its own UE the SRS is transmitted. This allows the PUSCH transmitting UE to transmit the PUSCH while avoiding the SRS, even if the numerology of the PUSCH and the SRS of another UE are different.

[0154] The above-mentioned (9) may be, for example, information that combines an SRS transmission cycle and an offset. This information may be, for example, the same as the information included in a notification from a base station to an SRS-transmitting UE. This allows, for example, the base station to notify a UE that transmits a PUSCH of signaling with the same SRS transmission setting content as that for an SRS-transmitting UE. As a result, for example, it is possible to reduce the amount of processing in the base station.

[0155] In the above (10-1), for example, if the above (10-1) is false, the UE may stop PUSCH transmission at a symbol before the earliest symbol in the SRS transmission symbol group in the slot. The above-mentioned stopping operation may be performed, for example, when a DMRS and / or PTRS associated with the PUSCH is not assigned to a symbol before the earliest symbol. The above-mentioned case may be, for example, when the subcarrier spacing in the SRS-transmitting UE is larger than the subcarrier spacing in the PUSCH-transmitting UE, and the symbol assigned to the SRS corresponds to a symbol near the beginning of the slot of the PUSCH-transmitting UE. This allows, for example, the PUSCH-transmitting UE to stop transmitting symbols in the PUSCH for which demodulation characteristics cannot be ensured in the base station, and as a result, the power consumption of the PUSCH-transmitting UE can be reduced.

[0156] In the above (10-2), for example, the UE may stop PUSCH transmission at symbols after the latest symbol in the SRS transmission symbol group when the above (10-2) is false. The above-mentioned stopping operation may be performed, for example, when a DMRS and / or a PTRS associated with the PUSCH is not assigned to a symbol before the latest symbol. This allows, for example, the PUSCH transmitting UE to stop transmitting symbols in the PUSCH for which demodulation characteristics cannot be ensured in the base station, and as a result, it is possible to reduce the power consumption of the PUSCH transmitting UE.

[0157] In the above (10-3), for example, the UE may stop PUSCH transmission in the range from the earliest symbol to the latest symbol among the SRS transmission symbol group in the slot, using the information in the above (10-3) indicating no. This allows, for example, the UE to easily execute processing for avoiding SRS symbols in a multiple SRS configuration. Furthermore, the UE can reduce the number of times it stops and resumes PUSCH transmission due to a multiple SRS configuration, thereby avoiding complexity in PUSCH transmission control in the UE.

[0158] As another example of the above (10-3), the UE may transmit a PUSCH in the range from the earliest symbol to the latest symbol of the SRS transmission symbol group in the slot, using the information in the above (10-3) indicating "Yes." The PUSCH transmission may be performed, for example, by avoiding only the symbols that actually transmit the PUSCH. This may, for example, improve the PUSCH transmission rate from the UE.

[0159] In the above (10-4), for example, the UE may use the information in the above (10-4) indicating no to avoid the configured SRS transmission symbol and perform PUSCH transmission. This makes it possible to easily avoid using the SRS transmission resource in the UE, for example.

[0160] As another example of the above (10-4), the UE may transmit a PUSCH in the configured SRS transmission symbol when the information in the above (10-4) indicates "Yes." The PUSCH transmission may be performed, for example, in a subcarrier different from the frequency resource in which the SRS is transmitted. This may, for example, improve the PUSCH rate from the UE.

[0161] In the above (10-5), for example, the UE may use the information in the above (10-5) indicating no to perform PUSCH transmission by avoiding the range from the start PRB to the end PRB of the SRS in the symbol set as the SRS. This makes it possible to easily avoid the symbols and / or subcarriers for SRS transmission in the UE.

[0162] As another example of the above (10-5), when the information in the above (10-5) indicates "Yes," the UE may transmit a PUSCH in the range from the start PRB to the end PRB of the SRS in the symbol set as the SRS. The PUSCH transmission may be performed, for example, by avoiding the subcarriers assigned as the comb of the SRS. This may, for example, improve the PUSCH rate from the UE.

[0163] In the above (11), for example, the UE may stop PUSCH transmission only when the beam used by the SRS is the same as the beam used by the UE itself. This makes it possible to avoid interference between the PUSCH and the SRS while ensuring the PUSCH transmission rate.

[0164] The UE may stop PUSCH transmission, stop DMRS transmission associated with PUSCH transmission, or stop PTRS transmission associated with PUSCH transmission, in an SRS transmission symbol included in the notification from the base station. The SRS transmission symbol may be a symbol of an SRS transmission candidate. This makes it possible to avoid collisions in time and frequency resources with SRS, including semi-persistent SRS and aperiodic SRS, for example. In the above, the signals and / or channels for which the UE stops transmitting may be defined by a standard, or may be determined and notified or broadcast by the base station to the UE. For example, RRC signaling may be used for this notification.

[0165] The above-mentioned PUSCH transmission may be stopped, for example, in the range from the earliest symbol to the latest symbol of the SRS transmission symbol group in a slot. This allows, for example, the UE to easily execute processing to avoid SRS symbols in a multiple SRS configuration. Furthermore, the UE can reduce the number of times that PUSCH transmission is stopped and resumed due to multiple SRS configuration, thereby avoiding complexity in PUSCH transmission control in the UE.

[0166] In the above description, the range from the earliest symbol to the latest symbol in the SRS transmission symbol group may be derived for each slot, for example. For example, if the transmission symbol of an SRS transmitted in a multi-slot period is the latest symbol, the latest symbol in the SRS transmission symbol group may be the transmission symbol of the SRS transmitted in that multi-slot period only in the slot corresponding to that period, and the latest symbol in the SRS transmission symbol group in other slots may be the latest symbol excluding the SRS transmitted in that multi-slot period. This makes it possible to prevent unnecessary PUSCH transmission suspension, for example, and as a result, to improve the PUSCH transmission rate.

[0167] 9 is a diagram showing an example in which a UE stops PUSCH transmission in a range from the earliest symbol to the latest symbol of an SRS transmission symbol group in a slot. Fig. 9 shows an example in which UE#1 transmits PUSCH 901 and PUSCH 902, UE#2 transmits periodic SRS 905 in odd-numbered slot numbers at a two-slot cycle, and UE#3 has aperiodic SRS (referred to as A-SRS in the diagram) configurations #1 906 and #2 907 configured.

[0168] In the example of Fig. 9, the periodic SRS of UE #2 is transmitted at the 13th symbol and at a rate of 1 RE every 4 REs in the frequency direction. Also in the example of Fig. 9, aperiodic SRS setting #1 set for UE #3 is set so that the aperiodic SRS is transmitted at the 10th and 11th symbols on the time axis and at a rate of 1 RE every 2 REs on the frequency axis. Also in the example of Fig. 9, aperiodic SRS setting #2 set for UE #3 is set so that the aperiodic SRS is transmitted at the 8th to 11th symbols on the time axis and at a rate of 1 RE every 2 REs on the frequency axis. In the example shown in Fig. 9, aperiodic SRS #1 set for UE #3 is transmitted as aperiodic SRS 908 in slot number 2, and aperiodic SRS #2 is transmitted as aperiodic SRS 909 in slot number 1.

[0169] In Fig. 9, the earliest SRS transmission symbol in slot number 0 is the 8th symbol, and the latest SRS transmission symbol is the 11th symbol. The earliest SRS transmission symbol and / or the latest SRS transmission symbol may be an SRS that is not actually transmitted, for example, an SRS that is set as aperiodic SRS and is not actually transmitted. In slot number 0 shown in Fig. 9, UE #1 can transmit PUSCH in symbols 0 to 7 and symbols 12 and 13. The UE transmits PUSCH 901 in these symbols using notification regarding SRS setting from the base station.

[0170] In slot number 1 shown in Fig. 9, the earliest SRS transmission symbol is the 8th symbol, and the latest SRS transmission symbol is the 13th symbol. UE #1 can transmit PUSCH in symbols 0 to 7. The UE transmits PUSCH 902 in those symbols using notification regarding SRS settings from the base station.

[0171] Slot numbers 2 and 3 shown in FIG. 9 are the same as slot numbers 0 and 1, respectively, and therefore will not be described.

[0172] As another example of stopping the PUSCH transmission described above, the PUSCH transmission may be stopped only in the SRS transmission symbol included in the notification from the base station, which may increase the PUSCH transmission rate from the UE, for example.

[0173] Fig. 10 is a diagram showing an example in which a UE stops PUSCH transmission only at the SRS transmission symbol notified to the UE. In Fig. 10, the SRS settings of each UE are the same as in Fig. 9. In Fig. 10, signals common to Fig. 9 are assigned the same reference numerals, and common descriptions will be omitted.

[0174] In Fig. 10, the SRS transmission symbols in slot number 0 are set to the 8th to 11th symbols. In the above description, the SRS transmission symbols may be symbols of SRS that are not actually transmitted, for example, SRS that is set as aperiodic SRS and is not actually transmitted, or may be symbols set as deactivated semi-persistent SRS. In slot number 0 shown in Fig. 10, UE #1 can transmit PUSCH in symbols 0 to 7 and symbols 12 and 13. The UE transmits PUSCH 1001 in these symbols using notification regarding SRS configuration from the base station.

[0175] In slot number 1 shown in Fig. 10, the SRS transmission symbols are set to symbols 8 to 11 and 13. UE #1 can transmit PUSCH in symbols 0 to 7 and 12. The UE transmits PUSCH 1002 in these symbols using notification regarding SRS settings from the base station.

[0176] Slot numbers 2 and 3 shown in FIG. 10 are the same as slot numbers 0 and 1, respectively, and therefore will not be described here.

[0177] As another example of UE behavior in response to an SRS transmission symbol included in a notification from a base station, the UE may transmit a PUSCH in the symbol, transmit a DMRS associated with the PUSCH, or transmit a PTRS associated with the PUSCH. The aforementioned PUSCH, DMRS, and / or PTRS transmission by the UE may be performed, for example, outside the PRB range of the SRS included in the SRS configuration notified to the UE from the base station. This enables the PUSCH transmission rate in the UE to be improved. In the above, the signal and / or channel to be transmitted by the UE may be defined by a standard, or may be determined by the base station and notified or broadcast to the UE. For example, RRC signaling may be used for the notification.

[0178] Fig. 11 is a diagram showing an example in which PUSCH transmission is performed outside the PRB range of an SRS transmission symbol notified to a UE. In Fig. 11, the SRS setting of each UE is the same as in Fig. 9. In Fig. 11, signals common to Fig. 9 are assigned the same reference numerals, and common descriptions will be omitted.

[0179] In slot number 0 shown in Fig. 11, UE #1 can transmit PUSCH across the entire PUSCH transmission band in symbols 0 to 7 and symbols 12 and 13. Also, in symbols 8 to 11 of slot number 0, UE #1 can transmit PUSCH in a range not included in aperiodic SRS configurations #1 906 and #2 907 of UE #3. The UE transmits PUSCH 1101 in the above-mentioned time and frequency resources using a notification regarding the SRS configuration from the base station.

[0180] In slot number 1 shown in Fig. 11, UE #1 can transmit PUSCH across the entire PUSCH transmission band in symbols 0 to 7 and 12. Also, in symbols 8 to 11 of slot number 1, UE #1 can transmit PUSCH in a range not included in aperiodic SRS configurations #1 906 and #2 907 of UE #3. The UE transmits PUSCH 1102 in the above-mentioned time and frequency resources using a notification regarding the SRS configuration from the base station.

[0181] Slot numbers 2 and 3 shown in FIG. 11 are the same as slot numbers 0 and 1, respectively, and therefore will not be described.

[0182] As another example of a UE transmitting a PUSCH in an SRS transmission symbol included in a notification from a base station, the UE may transmit a PUSCH within a PRB range of the SRS included in the SRS configuration notified to the UE from the base station. The PUSCH transmission may be performed, for example, by avoiding the RE to which the SRS is actually assigned, i.e., the comb configuration. This may, for example, improve the PUSCH transmission rate in the UE.

[0183] The UE may transmit the PUSCH both outside and within the PRB range of the SRS in the SRS transmission symbol included in the notification from the base station, which may further improve the PUSCH transmission rate in the UE, for example.

[0184] Fig. 12 is a diagram showing an example in which PUSCH transmission is performed outside the PRB range and within the PRB range of the SRS in an SRS transmission symbol notified to a UE. In Fig. 12, the SRS setting of each UE is the same as in Fig. 9. In Fig. 12, signals common to Fig. 9 are assigned the same reference numerals, and common explanations will be omitted.

[0185] In slot number 0 shown in Fig. 12, UE #1 can transmit PUSCH over the entire PUSCH transmission band in symbols 0 to 7 and symbols 12 and 13. Also, in symbols 8 to 11 of slot number 0, UE #1 can transmit PUSCH in the range not included in aperiodic SRS configurations #1 906 and #2 907 of UE #3 and in REs to which the SRS is not allocated. The UE transmits PUSCH 1201 in the above-mentioned time and frequency resources using a notification regarding the SRS configuration from the base station.

[0186] In slot number 1 shown in FIG. 12, UE #1 can transmit PUSCH over the entire PUSCH transmission band in symbols 0 to 7 and 12. Furthermore, in symbols 8 to 11 of slot number 1, UE #1 can transmit PUSCH in the range not included in aperiodic SRS configurations #1 906 and #2 907 of UE #3 and in REs to which the SRS is not allocated. Furthermore, in the 13th symbol of slot number 1, UE #1 can transmit PUSCH in REs to which the periodic SRS configuration 905 of UE #2 is not allocated. The UE transmits PUSCH 1202 in the above-mentioned time and frequency resources using notification regarding the SRS configuration from the base station.

[0187] Slot numbers 2 and 3 shown in FIG. 12 are the same as slot numbers 0 and 1, respectively, and therefore will not be described here.

[0188] The base station may notify the UE of information regarding changes in the SRS configuration of other UEs. The UE may use the notification to change the time and / or frequency resources for PUSCH transmission. This may, for example, reduce interference between the PUSCH and the SRS of other UEs after the SRS configuration of the other UEs is changed.

[0189] The base station may notify the UE of a change in the SRS configuration of another UE each time the change occurs. This allows, for example, the SRS configuration change of another UE to be immediately reflected in PUSCH transmission, thereby suppressing interference between the PUSCH and the SRS of another UE. In the above, the base station may notify the UE of only information on the difference in the configuration change. This, for example, makes it possible to reduce the amount of signaling from the base station to the UE.

[0190] The base station may send the notification to the UE at predetermined intervals. This makes it possible to reduce the amount of signaling from the base station to the UE, for example, when the SRS settings of other UEs are frequently changed. The base station may not send the notification to the UE in some cases. For example, when there are no changes to the SRS settings of other UEs during the period, the base station may not send the notification to the UE. This makes it possible to reduce the amount of signaling from the base station to the UE, for example. In the above example, the base station may notify the UE of only information about the difference in settings that has been changed. This makes it possible to reduce the amount of signaling from the base station to the UE, for example.

[0191] Another solution will be disclosed. The base station may broadcast information about the SRS configuration of the UE under its control to the UE under its control. This, for example, makes it possible to reduce the amount of signaling related to this information from the base station. The broadcast may be performed, for example, using Other SI (see Non-Patent Document 16 (TS38.300 v15.0.0)) among System Information (SI) or Remaining Minimum SI (RMSI) (see Non-Patent Document 16 (TS38.300 v15.0.0)). A dedicated SIB may be provided. The content included in the broadcast may be the same as (1) to (11) disclosed as the information about SRS transmission resource candidates notified from the base station to the UE in the above-mentioned solution.

[0192] Another solution will be disclosed. The base station may dynamically notify a PUSCH-transmitting UE of information regarding SRS transmissions of other UEs. The notification may be, for example, a slot-by-slot notification. For example, L1 / L2 signaling may be used for the notification. This enables, for example, quick notification to the UE. In addition, it may be possible to stop PUSCH transmission only for symbols where SRS is actually transmitted, thereby improving the PUSCH transmission rate.

[0193] As another example, the notification may use DCI of Group Common Signaling (see Non-Patent Document 14 (TS38.213 v15.0.0)). This makes it possible to notify multiple UEs of information regarding SRS transmissions from other UEs at the same time.

[0194] The group-wide signaling may be, for example, group-wide signaling for some or all UEs in a beam, which allows the information to be notified collectively to UEs communicating using the same beam, thereby reducing the amount of signaling.

[0195] The UE may be able to receive the group-common signaling every slot, which allows the UE to avoid SRS transmissions from other UEs every slot, for example.

[0196] Information regarding SRS transmission by other UEs may be included in DCI of an uplink grant for a PUSCH-transmitting UE, or may be DCI different from the uplink grant.

[0197] As another example, the information may be notified by being included in a PDCCH different from the uplink grant. For example, when an SRS transmission of another UE becomes necessary after an uplink grant for a PUSCH transmission UE is notified, the information may be notified by being included in a PDCCH different from the uplink grant. This makes it possible for a PUSCH transmission UE to avoid collision of time and frequency resources with SRS transmission of another UE, even when there is a long waiting time between receiving the uplink grant and transmitting the PUSCH.

[0198] As another example, the information may be notified using a notification indicating that preemption will be performed, for example, a preemption indication, which allows the base station to quickly notify the PUSCH-transmitting UE.

[0199] As another example, the information may be transmitted using MAC signaling. Multi-level modulation allows more information to be transmitted, and HARQ retransmission can improve reliability.

[0200] The following items (1) to (12) are disclosed as information regarding SRS transmission from other UEs that is dynamically notified from the base station to the PUSCH-transmitting UE.

[0201] (1) Information that identifies the SRS settings.

[0202] (2) Type of SRS setting.

[0203] (3) Information about SRS transmission symbols.

[0204] (4) Information about SRS transmission frequencies.

[0205] (5) Information about the sequence of the SRS.

[0206] (6) Information about SRS Comb settings.

[0207] (7)SRS antenna port.

[0208] (8) SRS numerology.

[0209] (9) Information about the slot in which the SRS is transmitted.

[0210] (10) Information on whether PUSCH transmission is possible. Examples of this information include the following (10-1) to (10-6).

[0211] (10-1) Information on whether or not PUSCH transmission is possible before the earliest symbol among the SRS transmission symbols in the slot.

[0212] (10-2) Information on whether or not PUSCH transmission is possible after the latest symbol among the SRS transmission symbols in the slot.

[0213] (10-3) Information regarding whether PUSCH transmission is possible within the range from the earliest symbol to the latest symbol of the SRS transmission symbol group within a slot.

[0214] (10-4) Information regarding whether PUSCH transmission is possible in the set SRS transmission symbol.

[0215] (10-5) Information regarding whether PUSCH transmission is possible within the set SRS transmission frequency resource within the set SRS transmission symbol.

[0216] (10-6) A combination of the above (10-1) to (10-5).

[0217] (11) Information about the beam used in SRS transmission.

[0218] (12) A combination of (1) to (11) above.

[0219] The above (1) to (8), (10), and (11) may be the same as the information about SRS transmission resource candidates semi-statically notified from the base station to the UE, as disclosed above.

[0220] The above (9) may be, for example, the slot number in which the SRS is transmitted, or the slot interval from when the base station transmits a notification to the UE until when the SRS is transmitted. This allows the UE to know the slot number in which the SRS is transmitted, and as a result, it is possible to prevent the UE from unnecessary suspension of PUSCH transmission.

[0221] The UE may stop PUSCH transmission using the notification from the base station. The operation of stopping PUSCH transmission in the UE may be the same as the operation using the semi-static notification described above.

[0222] Fig. 13 is a diagram showing an example in which a base station notifies a UE of information related to SRS transmission of other UEs for each slot. Fig. 13 shows a case in which a UE does not transmit PUSCH only in the notified SRS transmission symbol. In Fig. 13, the SRS setting of each UE is the same as in Fig. 9. In Fig. 13, signals common to Fig. 9 are assigned the same reference numerals, and common explanations will be omitted.

[0223] In downlink slot number n shown in FIG. 13, the base station notifies UE #1 of an uplink grant included in DCI 1301. The SRS settings of other UEs are not included in DCI 1301. UE #1 transmits PUSCH 1311 in symbols 0 to 13 in uplink slot number 0.

[0224] In downlink slot number (n+1) shown in FIG. 13, the base station notifies UE #1 of an uplink grant included in DCI 1302. DCI 1302 includes information on UE #2's periodic SRS 905 and UE #3's aperiodic SRS #2 909. UE #1 uses DCI 1302 to transmit PUSCH 1312 in symbols 0 to 7 and 12 in uplink slot number 1.

[0225] In downlink slot number (n+2) shown in FIG. 13, the base station notifies UE#1 of an uplink grant included in DCI 1303. DCI 1303 includes information related to UE#3's aperiodic SRS#2 908. UE#1 uses DCI 1303 to transmit PUSCH 1313 in symbols 0 to 9, 12, and 13 in uplink slot number 2.

[0226] In downlink slot number (n+3) shown in FIG. 13, the base station notifies UE#1 of an uplink grant included in DCI 1304. DCI 1304 includes information about UE#2's periodic SRS 905. UE#1 uses DCI 1304 to transmit PUSCH 1314 in symbols 0 to 12 of uplink slot number 3.

[0227] Another solution will be disclosed. A base station semi-statically notifies a UE in advance of SRS transmission resource candidates configured for the UE under its control. RRC dedicated signaling may be used for the notification, or the SRS transmission resource candidates may be broadcast to the UE under its control instead of notification. The SRS transmission resource candidates may include, for example, all resource configurations configured for aperiodic SRS, resource configurations configured for semi-persistent SRS, or resource configurations for periodic SRS. The content of the semi-static notification may be some or all of (1) to (12) disclosed above as information on SRS transmission resource candidates semi-statically notified from the base station to the UE. The base station may dynamically notify the UE of information on SRS actually transmitted from other UEs. The content of the dynamic notification may apply to (1) to (12) disclosed above as information on SRS transmission resource candidates dynamically notified from the base station to the UE. All or some of (1) to (12) may be applied, for example, only the information in (1) may be applied. This makes it possible, for example, to use SRS allocation symbols that are not actually transmitted for PUSCH transmission of the UE, thereby enabling the PUSCH transmission rate to be improved.

[0228] The dynamic notification from the base station to the UE may include, for example, an identifier for the aperiodic SRS configuration, information indicating that the semi-persistent SRS has been activated or deactivated, an identifier for the semi-persistent SRS configuration, information regarding the slot in which the semi-persistent SRS is activated or deactivated, or a combination of two or more of the above. This may, for example, reduce the amount of signaling required for the dynamic notification.

[0229] In the notification from the base station to the PUSCH transmission UE disclosed in the first embodiment, information on the time and / or frequency resource for stopping PUSCH transmission may be notified instead of information on SRS transmission resource candidates. The PUSCH transmission UE may stop PUSCH transmission using this information. This makes it possible to reduce the amount of signaling, for example, because the content of the notification from the base station to the UE is only information on the PUSCH transmission stop resource.

[0230] As another example, discrete time and / or frequency allocation may be performed in an uplink grant notified from the base station to the PUSCH transmission UE. Information on the discrete allocation may be included in the uplink grant. An example of such information may be a bitmap. The UE may use the allocation information to perform PUSCH transmission discretely on the time and / or frequency axes. This allows flexible scheduling from the base station to the UE.

[0231] The discrete PUSCH allocation described above may be applied when no conflict of time and / or frequency resources occurs between the PUSCH and the SRS. For example, it may be used when some time and / or frequency resources are shared between PUSCH scheduling for a PUSCH-transmitting UE and PUSCH scheduling for a UE using a different numerology. In the above situation, for example, the discrete PUSCH allocation may be performed after or simultaneously with PUSCH allocation for a UE using a different numerology. In this respect, it differs from preemption. This, for example, enables improved flexibility in scheduling from a base station to each UE under its control.

[0232] The operation method of the PUSCH transmitting UE disclosed in the first embodiment may be statically determined, or may be determined by the base station and notified to the UE, or may be broadcast.

[0233] In the above description, as an example of a statically determined case, the operation of the PUSCH transmitting UE may be determined based on information about symbols to which DMRS is assigned. For example, if no DMRS is assigned to symbols before the earliest symbol in the SRS transmission symbol group within a slot, the PUSCH transmitting UE may stop PUSCH transmission. The same may be done for symbols after the latest symbol in the SRS transmission symbol group, or for symbols to which SRS transmission is not assigned within the range from the earliest symbol to the latest symbol. For symbols to which SRS transmission is not assigned within the range from the earliest symbol to the latest symbol in the SRS transmission symbol group, consecutive symbols to which SRS is not assigned may be treated as one symbol group, and whether or not PUSCH transmission is possible may be determined based on the presence or absence of DMRS in the symbol group. This allows, for example, the PUSCH transmitting UE to stop transmitting symbols in the PUSCH for which demodulation characteristics cannot be ensured in the base station, thereby reducing power consumption of the PUSCH transmitting UE.

[0234] As another example where the operation of a PUSCH-transmitting UE is defined by a standard, a modulation scheme for the PUSCH of the PUSCH-transmitting UE may be used. For example, when OFDM is used to modulate the PUSCH, the PUSCH may be transmitted in an RE in an SRS transmission symbol to which no SRS is assigned. This makes it possible to ensure, for example, a PUSCH transmission rate. As another example, when DFT-spread OFDM (DFT-s-OFDM) is used to modulate the PUSCH, PUSCH transmission may not be performed in the SRS transmission symbol. This makes it possible to prevent, for example, degradation of the PAPR in the PUSCH-transmitting UE.

[0235] As an example of a case where the base station determines the operation of the PUSCH-transmitting UE disclosed in the first embodiment and notifies the UE, the notification may be performed semi-statically, for example, by using RRC dedicated signaling, or dynamically, for example, by using MAC signaling and / or L1 / L2 signaling. The notification content in the semi-static notification may include, for example, the above-mentioned disclosed information on SRS transmission of other UEs that is semi-statically notified from the base station to the PUSCH-transmitting UE (10). The notification content in the dynamic notification may include, for example, the above-mentioned disclosed information on SRS transmission of other UEs that is dynamically notified from the base station to the PUSCH-transmitting UE (10).

[0236] A PUSCH transmitting UE may not transmit uplink data mapped to symbols or REs for which transmission has been stopped in response to an SRS configuration notification from another UE from a base station, which can, for example, avoid complexity in PUSCH transmission processing in the UE.

[0237] As another example, a PUSCH transmitting UE may transmit uplink data mapped to a symbol or RE for which transmission has been stopped using an SRS configuration notification of another UE from a base station, in a subsequent symbol. This makes it possible to ensure, for example, code continuity during demodulation and / or decoding by the base station, and as a result, for example, to ensure decoding performance.

[0238] In the above, the coding rate of the PUSCH may not be changed. In the above, the UE may transmit the uplink data in a later symbol or another RE, so that the uplink data mapped to the last PUSCH is not transmitted. This can avoid, for example, complexity in the PUSCH transmission process in the UE.

[0239] As another example of the above, the coding rate of the PUSCH may be changed. For example, the coding rate may be increased. This allows the UE to transmit uplink data mapped to the last PUSCH to the base station, for example. Information regarding the change in coding rate may be defined by a standard, or may be determined by the base station and notified to the UE in advance. This notification may be performed using RRC signaling, MAC signaling, or L1 / L2 signaling. Information regarding the change in coding rate may be notified to the UE from the base station, for example, together with information regarding SRS transmission from other UEs, which is dynamically notified to the PUSCH-transmitting UE from the base station.

[0240] As another example, when there is a symbol or RE for which the UE stops PUSCH transmission in response to an SRS configuration notification from another UE from the base station, the UE may not allocate uplink data to the symbol or RE. The above-mentioned process of not allocating uplink data may be performed, for example, in the encoding process and / or modulation process in the UE. This allows, for example, the UE to easily perform the process of mapping uplink data to the PUSCH. In the above-mentioned process of not allocating uplink data, the coding rate may not be changed, or the coding rate may be changed. Information regarding the change in the coding rate may be defined by a standard, or may be determined by the base station and notified to the UE in advance. For this notification, RRC signaling, MAC signaling, or L1 / L2 signaling may be used. For example, information regarding the change in the coding rate may be notified to the UE from the base station together with information regarding SRS transmission from another UE, which is dynamically notified to the PUSCH-transmitting UE from the base station.

[0241] Information on whether or not to allocate uplink data to the symbol or RE from the base station to the UE may be predefined in a standard, or may be determined by the base station and notified or broadcast to the UE. For example, RRC signaling may be used for the notification. This allows, for example, flexible control of uplink transmission in a communication system.

[0242] In this first embodiment, the notification of the SRS configuration from the base station to the UE may be made to the UE in any of the states of RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED (see Non-Patent Document 16). The notification may be included in, for example, signaling of an RRC connection reconfiguration. This allows the UE to acquire the SRS configuration when an RRC connection with the base station is established, thereby making it possible to avoid interference between the SRS of another UE and the PUSCH of the UE from the start of communication between the UE and the base station. As another example, the notification of the SRS configuration may be made only to UEs in the RRC_CONNECTED state. This makes it possible to reduce, for example, the amount of signaling for notifications from the base station to subordinate UEs. The above-mentioned two methods may also be combined. For example, the initial notification of the SRS setting from the base station to the UE may be sent to the UE in any of the RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states, and the notification of the change in the SRS setting may be sent only to the UE in the RRC_CONNECTED state. This makes it possible to reduce the amount of signaling from the base station to the UE, while avoiding interference between the SRS of other UEs and the PUSCH of the UE, for example, from the start of communication between the UE and the base station.

[0243] In the first embodiment, the SRS configuration included in the notification from the base station to the UE may be different for each UE. As an example of a case where the base station notifies each UE of a different SRS configuration, the base station may only notify the SRS configuration to be transmitted for the beam to which the UE belongs. This makes it possible to reduce the size of the signaling of the SRS configuration.

[0244] As another example, the SRS configuration may be limited to SRS configurations transmitted to multiple beams including the beam to which the UE belongs. This eliminates the need for the base station to retransmit signaling to the UE even when inter-beam mobility occurs in the UE. The multiple beams may include beams surrounding the beam to which the UE belongs, or may be beams distant from the beam to which the UE belongs, such as beams that enable communication by reflected waves from the beam.

[0245] As another example, the SRS configuration may be limited to only the SRS configuration including the frequency resources of the BWP (Bandwidth part) (see Non-Patent Document 14 (TS38.213 v15.0.0)) that is active in the UE, which may reduce the signaling size of the SRS configuration, for example.

[0246] As another example, the SRS configuration may be limited to the SRS configuration including the frequency resources of the BWP configured for the UE, which eliminates the need for the base station to retransmit signaling to the UE even when a BWP switch occurs in the UE.

[0247] As another example, the SRS configuration may be limited to the SRS configuration including the time and / or frequency resources that the base station schedules for the UE. For example, the above may be applied when the time and / or frequency resources that the base station allocates to the UE are predetermined. This may reduce the amount of signaling from the base station to the UE, for example.

[0248] The above examples may be combined. That is, in the first embodiment, the SRS configuration included in the notification from the base station to the UE may be only the SRS configuration to be transmitted to the beam to which the UE belongs and the SRS configuration including the frequency resource of the BWP (Bandwidth part) that is active in the UE. This makes it possible to further reduce the amount of signaling from the base station to the UE.

[0249] In the first embodiment, a DMRS may be additionally transmitted. For example, a DMRS may be transmitted when PUSCH transmission is resumed. The DMRS may be an already configured DMRS (for example, an additional DMRS), or a new DMRS may be configured.

[0250] A new DMRS may be provided after the SRS. For example, when a 14-symbol PUSCH transmission is configured, a new DMRS may be provided at the 12th and / or 13th symbol. This makes it possible to improve the demodulation performance of the base station when the PUSCH resumes at the 12th and 13th symbols, for example, if another UE transmits an SRS at the 11th symbol.

[0251] As another example, a new DMRS may be provided before an SRS, which may improve the PUSCH demodulation performance in the symbol immediately before the SRS.

[0252] As another example, the new DMRS may be provided both before and after the SRS, which may provide a combination of the above-mentioned effects.

[0253] The information regarding the transmission of the new DMRS may be determined by a standard or may be determined by the base station and notified or broadcast to the UE using RRC signaling, MAC signaling, L1 / L2 signaling, or a combination of the above.

[0254] The following (1) to (5) are disclosed as information regarding the transmission of the new DMRS.

[0255] (1) Information indicating whether a new DMRS is to be placed before an SRS, for example, an identifier.

[0256] (2) Information indicating whether a new DMRS is to be provided after an SRS, for example, an identifier.

[0257] (3) Information about the transmission symbols of the new DMRS, such as the symbol number and the number of symbols.

[0258] (4) Information about the transmission RE interval and offset of the new DMRS.

[0259] (5) A combination of (1) to (4) above.

[0260] The above (1) and / or (2) can improve the demodulation characteristics of the PUSCH in the base station before and / or after the SRS transmission, for example.

[0261] The above (3) enables, for example, flexible DMRS allocation in a communication system.

[0262] In the above (4), the UE may allocate the PUSCH to an RE where the DMRS is not allocated, thereby making it possible to ensure the transmission rate of the PUSCH, for example.

[0263] 14 is a diagram showing an example of adding a DMRS before and after an SRS is transmitted from another UE. In the example of FIG. 14, an additional DMRS 1401 is transmitted from the UE in the 10th and 12th symbols.

[0264] In the first embodiment, a PTRS may be additionally transmitted. For example, when the PTRS transmission interval is two symbols or more, a new PTRS may be provided.

[0265] A new PTRS may be provided after the SRS, which allows the base station to compensate for phase noise in the PUSCH symbol immediately after the SRS transmission, thereby improving the PUSCH demodulation performance of the base station.

[0266] As another example, a new PTRS may be provided before the SRS, thereby achieving the above-described effect, for example, in the PUSCH symbol immediately before the SRS.

[0267] As another example, a new PTRS may be provided both before and after the SRS, thereby achieving the above-described effect, for example, immediately before and after the SRS.

[0268] The information regarding the transmission of the new PTRS may be determined by a standard or may be determined by the base station and notified or broadcast to the UE using RRC signaling, MAC signaling, L1 / L2 signaling, or a combination of the above.

[0269] The following (1) to (4) are disclosed as information regarding the transmission of new PTRS.

[0270] (1) Information indicating whether a new PTRS is to be placed before an SRS, e.g., an identifier.

[0271] (2) Information indicating whether a new PTRS is to be placed after the SRS, for example, an identifier.

[0272] (3) Information about the transmission symbol of the new PTRS, such as the symbol number.

[0273] (4) A combination of (1) to (3) above.

[0274] The above (1) and / or (2) can improve the demodulation characteristics of the PUSCH in the base station before and / or after the SRS transmission, for example.

[0275] The above (3) makes it possible to improve the flexibility in PTRS placement, for example.

[0276] The information regarding the transmission of a new PTRS may be determined for each UE or for each SRS. Setting the information for each UE can, for example, reduce signaling related to the setting. Setting the information for each SRS can, for example, improve the flexibility of the setting related to the transmission of a PTRS.

[0277] Figure 15 shows an example of adding a PTRS after an SRS transmission from another UE. The example in Figure 15 shows a case where PTRS 1501 is transmitted at a rate of 1 RE every 4 symbols, and a third PTRS is assigned to the same symbol as SRS 1502 transmitted by UE #2. In Figure 15, an additional PTRS 1503 is transmitted in the symbol following SRS 1502.

[0278] In the above description, transmission of an additional PTRS may be applied when the PUSCH-transmitting UE itself transmits an SRS. For example, the SRS transmission of UE #2 in FIG. 15 may be the PUSCH-transmitting UE itself. This makes it possible to improve demodulation characteristics in the base station when transmitting a PUSCH after the UE itself transmits an SRS.

[0279] The method disclosed in the first embodiment may be applied when a UE allocates a PUSCH before or after an SRS symbol or a group of SRS symbols. For example, a base station may notify a UE in advance of SRS transmission resource candidates configured for a subordinate UE, and the UE may stop PUSCH transmission in the SRS transmission resource. A PRB range in an SRS configuration notification from a base station to a UE may be notified in units of the number of PRBs, which is the SRS configuration resolution. A base station may notify a UE of only an SRS configuration including the frequency range of the active BWP of the UE. A base station may notify a UE of only an SRS configuration for a beam to which the UE belongs. A base station may also broadcast an SRS configuration to a UE. An additional DMRS may be provided before or after SRS transmission, and similarly, an additional PTRS may be provided. This provides the same effects as those described above.

[0280] According to the first embodiment, even when SRS transmission from another UE is performed in a PUSCH transmission period, the PUSCH transmission rate can be ensured.

[0281] Variation 1 of Embodiment 1 Another solution will be disclosed for the allocation of the PUSCH of the own UE and the SRS of another UE disclosed in the first embodiment.

[0282] An SRS-transmitting UE may not transmit SRS in the symbol and frequency band to which the PUSCH transmitted by the PUSCH-transmitting UE is assigned. In the above description, the SRS-transmitting UE may transmit SRS in a symbol other than the symbol or outside the band. A PUSCH-transmitting UE may continue PUSCH transmission in the symbol to which the SRS is assigned. This allows, for example, sounding by the SRS-transmitting UE to be performed while maintaining the PUSCH transmission rate. The SRS may be transmitted using the same numerology as the PUSCH, or using a different numerology.

[0283] An SRS-transmitting UE may not transmit an SRS in the frequency band of the PUSCH in a symbol to which a DMRS associated with the PUSCH is allocated. This may improve, for example, the demodulation performance of the PUSCH in a base station. The same may be done for a PTRS associated with the PUSCH. Similar effects can be achieved. As another example, when a PUSCH transmitted by a PUSCH-transmitting UE includes information on aperiodic CSI reporting, the SRS-transmitting UE may not transmit an SRS in the frequency band of the PUSCH. This may improve the reliability of aperiodic CSI reporting.

[0284] 16 is a diagram showing an example in which an SRS transmission from an SRS-transmitting UE is not performed in the symbol and frequency band to which the PUSCH transmitted by the PUSCH-transmitting UE is allocated, but the SRS transmission from the SRS-transmitting UE is performed in a symbol other than the allocated symbol or outside the allocated band. In the example shown in FIG. 16, the subcarrier intervals for the PUSCH and the SRS are the same. In the example shown in FIG. 16, the PUSCH-transmitting UE transmits a DMRS 1601 associated with the PUSCH in the second symbol, and transmits a PTRS 1602 associated with the PUSCH every symbol on two subcarriers. In the example shown in FIG. 16, the SRS-transmitting UE is configured to transmit an SRS in the 11th symbol, at intervals of two subcarriers.

[0285] 16, the SRS-transmitting UE does not transmit the SRS in RE 1605 included in the frequency band occupied by the PUSCH 1603 and PTRS 1602 of the PUSCH-transmitting UE. The SRS-transmitting UE transmits the SRS in RE 1606 outside the frequency band.

[0286] Another solution will be disclosed. An SRS-transmitting UE may transmit an SRS in a symbol and frequency band to which a PUSCH transmitted by a PUSCH-transmitting UE is allocated. A PUSCH-transmitting UE may not transmit a PUSCH in an RE in which the time and frequency resources overlap with those of the SRS. In the above, an SRS-transmitting UE may change the density of the SRS comb. For example, the density may be reduced. This makes it possible to ensure, for example, a PUSCH transmission rate. As another example, an SRS-transmitting UE may transmit an SRS by changing the offset of the SRS comb. This makes it possible, for example, for the SRS-transmitting UE to transmit an SRS while avoiding a PTRS transmitted by a PUSCH-transmitting UE. Both of the above examples may be combined. This, for example, makes it possible to obtain both of the above effects.

[0287] The above-mentioned SRS transmission may be performed when the PUSCH is OFDM modulated. When the PUSCH is DFT-spread OFDM modulated (DFT-s-OFDM), the above-mentioned SRS transmission may not be performed. This makes it possible to prevent degradation of the Peak-to-Average Power Ratio (PAPR) in PUSCH transmission from a PUSCH-transmitting UE. As another example, the above-mentioned SRS transmission may be performed when the PUSCH is DFT-spread OFDM modulated. Sounding from an SRS-transmitting UE can be performed in a wideband.

[0288] Figure 17 is a diagram showing an example in which SRS transmission from an SRS-transmitting UE is performed by changing the comb density in the symbol and frequency band to which the PUSCH transmitted by the PUSCH-transmitting UE is allocated. In Figure 17, the settings for each UE are the same as in Figure 16. In Figure 17, signals that are common to Figure 16 are assigned the same reference numerals, and common descriptions will be omitted.

[0289] 17, the SRS-transmitting UE changes the comb spacing of the SRS from 2 RE to 4 RE and transmits the SRS in RE 1704 included in the frequency band occupied by the PUSCH 1603 and PTRS 1602 of the PUSCH-transmitting UE. In RE 1705, the SRS is not transmitted, and the PUSCH 1603 or PTRS 1602 is transmitted instead.

[0290] The base station may notify the PUSCH-transmitting UE of information related to SRS transmission. The information included in the notification may be the same as that in the first embodiment.

[0291] Another solution is disclosed. The SRS-transmitting UE may not transmit the SRS in a symbol to which the PUSCH transmitted by the PUSCH-transmitting UE is allocated. In the above, the SRS-transmitting UE may not transmit the SRS in a frequency band other than the frequency band to which the PUSCH of the PUSCH-transmitting UE is allocated. This allows, for example, the base station to allocate a PUSCH to another UE in a frequency band other than the allocated frequency band, thereby increasing the communication capacity in the communication system.

[0292] The above-mentioned operation of not transmitting the SRS may be applied, for example, when the numerology of the PUSCH and the SRS are different. For example, when the subcarrier spacing of the SRS is larger than that of the PUSCH, the SRS transmission from the SRS-transmitting UE may not be performed. This makes it possible to prevent interference with the PUSCH caused by SRS transmission outside the PUSCH band, which occurs due to differences in subcarrier spacing.

[0293] Figure 18 is a diagram showing an example in which SRS transmission from an SRS-transmitting UE is not performed in a symbol to which a PUSCH transmitted by a PUSCH-transmitting UE is assigned. In Figure 18, the settings for each UE are the same as in Figure 16. In Figure 18, signals that are common to Figure 16 are assigned the same reference numerals, and common descriptions will be omitted.

[0294] 18 , the SRS-transmitting UE transmits the SRS neither in RE 1804 included in the frequency band occupied by the PUSCH 1603 and PTRS 1602 of the PUSCH-transmitting UE, nor in RE 1805 not included in the frequency band. The PUSCH 1603 or PTRS 1602 is transmitted in RE 1804 and RE 1805.

[0295] Other solutions will be disclosed. (a) As disclosed above, it is possible to combine or switch between the cases where an SRS-transmitting UE does not transmit an SRS and transmits an SRS in the symbol and frequency band to which a PUSCH transmitted by the PUSCH-transmitting UE is allocated, (b) where an SRS is not transmitted both inside and outside the frequency band, and (c) as disclosed in the first embodiment, where a PUSCH-transmitting UE does not transmit a PUSCH in the symbol to which the SRS-transmitting UE transmits an SRS or transmits it only in some frequency resources.

[0296] As an example of the above combination, in the allocated band of the PUSCH from the PUSCH-transmitting UE, the PUSCH-transmitting UE may transmit the DMRS and / or PTRS associated with the PUSCH in REs to which the DMRS and / or PTRS are allocated, and the SRS-transmitting UE may transmit the SRS in other REs. This, for example, enables wideband sounding from the SRS-transmitting UE and improves the demodulation performance of the PUSCH in the base station.

[0297] As an example of the switching described above, an SRS-transmitting UE may not transmit an SRS within the PUSCH-allocated band in a symbol to which a DMRS and / or PTRS associated with a PUSCH transmitted from the PUSCH-transmitting UE is allocated, but may transmit an SRS within the band outside the symbol. This enables, for example, wideband sounding from the SRS-transmitting UE and improves the demodulation performance of the PUSCH at the base station.

[0298] The operation of an SRS-transmitting UE in the symbols and frequency bands to which a PUSCH is allocated, as disclosed in this Modification 1, may be defined by a standard, or may be determined by the base station and notified or broadcast to the UE. The notification may be performed semi-statically using RRC signaling, dynamically using MAC signaling, dynamically using L1 / L2 signaling, or a combination of the above.

[0299] The base station may notify or broadcast information about SRS transmission to the PUSCH-transmitting UE. The information included in the notification may be the same as that in the first embodiment.

[0300] The following items (1) to (11) are disclosed as information to be notified from the base station to the SRS-transmitting UE described above.

[0301] (1) Information that identifies your SRS settings.

[0302] (2) Type of your SRS setting.

[0303] (3) Information about the SRS transmission symbol.

[0304] (4) Information about your SRS transmission frequency.

[0305] (5) Information about the sequence of your own SRS.

[0306] (6) Information about the comb settings of your SRS.

[0307] (7) Antenna port of own SRS.

[0308] (8) Information about the slot in which the SRS is to be transmitted.

[0309] (9) Information regarding the operation of your own SRS transmission.

[0310] (10) Information about the PUSCH transmitted by the PUSCH-transmitting UE. Examples of this information include the following (10-1) to (10-7).

[0311] (10-1) Information about PUSCH frequency resources.

[0312] (10-2) Information about time resources of PUSCH, such as transmission symbols of PUSCH.

[0313] (10-3) Information about DMRS associated with PUSCH.

[0314] (10-4) Information about PTRS accompanying PUSCH.

[0315] (10-5) Information about PUSCH modulation method.

[0316] (10-6) Information about uplink data transmitted via PUSCH.

[0317] (10-7) A combination of the aforementioned (10-1) to (10-6).

[0318] (11) A combination of (1) to (10) above.

[0319] The above (1) to (7) may be the same information as (1) to (7) disclosed as information on SRS transmission resource candidates semi-statically notified from the base station to the UE in the first embodiment.

[0320] The above (8) may be the same information as (9) disclosed as information on SRS transmission resource candidates dynamically notified from the base station to the UE in the first embodiment.

[0321] The above (9) may be, for example, information indicating that SRS transmission is not performed in the frequency band of the PUSCH, information indicating that SRS transmission is performed in the frequency band of the PUSCH, or information indicating that SRS transmission is not performed in symbols overlapping with the PUSCH. The SRS-transmitting UE may use this information to perform the operation disclosed in the first embodiment or this first modification. This enables, for example, flexible control of PUSCH transmission and SRS transmission in a communication system.

[0322] The above (10-1) may be, for example, the first PRB, the last PRB, or the number of PRBs of the PUSCH allocated by the base station to the PUSCH-transmitting UE, or a combination of two or more of the above. The SRS-transmitting UE may transmit the SRS by avoiding the frequency resources allocated to the PUSCH using the information in the above (10-1). This makes it possible to perform sounding between the SRS-transmitting UE and the base station while maintaining the PUSCH transmission rate in the communication system.

[0323] The above (10-2) may be, for example, the first symbol, the last symbol, or the number of symbols of the PUSCH assigned by the base station to the PUSCH-transmitting UE, or a combination of two or more of the above. The SRS-transmitting UE may use the information in the above (10-2) to transmit the SRS, for example, using symbols other than those assigned to the PUSCH. This makes it possible, for example, to perform wideband sounding between the SRS-transmitting UE and the base station while maintaining the PUSCH transmission rate in the communication system.

[0324] The above (10-3) may be, for example, information about symbols assigned to DMRSs associated with PUSCHs. The information may be, for example, the symbol number of the DMRS, or may include information about the number of symbols (e.g., the number of consecutive DMRS symbols). Another example may be a bitmap in which each symbol is associated with each bit. The SRS-transmitting UE may use the information in the above (10-3) to transmit the SRS, for example, by avoiding the symbols assigned to the DMRS. This may enable wideband sounding between the SRS-transmitting UE and the base station while maintaining the demodulation performance of the PUSCH at the base station.

[0325] Another example of the above (10-3) may be information on frequency resources allocated to a DMRS associated with a PUSCH. The SRS-transmitting UE may use the information of the above (10-3) to transmit the SRS, for example, by avoiding the RE allocated to the DMRS. This makes it possible to improve the reliability of sounding between the SRS-transmitting UE and the base station while ensuring the demodulation performance of the PUSCH at the base station.

[0326] The above-mentioned (10-4) may be, for example, information in which the DMRS in the above-mentioned (10-3) is replaced with the PTRS, thereby obtaining, for example, the same effect as the above-mentioned (10-3).

[0327] The above (10-5) may be, for example, information indicating that the PUSCH is OFDM modulated, or information indicating that the PUSCH is DFT-spread OFDM modulated. The SRS-transmitting UE may, for example, use the information indicating that the PUSCH is OFDM modulated to transmit the SRS in time and frequency resources that collide with the PUSCH. This makes it possible, for example, to perform sounding between the SRS-transmitting UE and the base station over a wide band. As another example, the SRS-transmitting UE may, for example, use the information indicating that the PUSCH is DFT-spread OFDM modulated to stop SRS transmission in time and frequency resources that collide with the PUSCH. This makes it possible, for example, to prevent degradation of the PAPR in the PUSCH.

[0328] The above (10-6) may be, for example, information indicating whether a PUSCH is used to transmit aperiodic CSI reports. The SRS transmitting UE may, for example, use the PUSCH to transmit aperiodic CSI reports to avoid transmitting SRS in time and / or frequency resources that collide with the PUSCH. This may ensure, for example, the reliability of transmission of aperiodic CSI reports.

[0329] The information (3) to (10) above may be provided separately for the time and / or frequency resource where collision with the PUSCH occurs and the time and / or frequency resource where collision does not occur. For example, the setting of (6) above may be different between the time and / or frequency resource where collision with the PUSCH occurs and the time and / or frequency resource where collision does not occur. This makes it possible to set the SRS comb density lower in the time and / or frequency resource where collision with the PUSCH occurs than in the time and / or frequency resource where collision does not occur, and as a result, it becomes possible to perform sounding between the SRS transmitting UE and the base station while maintaining the PUSCH transmission rate.

[0330] The above information (3) to (10) may be provided for each PUSCH allocation. For example, when frequency and / or time resources for PUSCHs of multiple UEs are shared in the SRS transmission band, it becomes possible to flexibly set the allocation of SRS to each PUSCH.

[0331] The above (3) to (10) may be provided separately for the SRS that the SRS-transmitting UE transmits and for the SRS that the SRS-transmitting UE does not transmit. Information indicating that SRS transmission will be performed may be included, or information indicating that SRS transmission will not be performed may be included. Both of the above may be included. The SRS-transmitting UE may use the separately provided information to determine whether or not to transmit SRS. This allows, for example, the base station to instruct whether or not to transmit SRS, thereby reducing the amount of processing in the SRS-transmitting UE.

[0332] The SRS transmission method and PUSCH transmission method disclosed above may also be applied when there are multiple SRS symbols. A combination and / or switching of the above methods may also be applied. For example, an SRS-transmitting UE may transmit the SRS in a symbol allocated to a PUSCH, rather than in a symbol allocated to a DMRS or PTRS associated with the PUSCH. This may enable sounding between the SRS-transmitting UE and the base station while maintaining the demodulation characteristics of the PUSCH at the base station. The above-described operation may also prevent the SRS of multiple symbols from being consecutive. For example, the second SRS symbol of four symbols used to transmit the SRS may not be transmitted. This may, for example, reduce complexity in design.

[0333] When a multiple-symbol SRS and a PUSCH from a PUSCH-transmitting UE collide in a time and / or frequency resource, an upper limit may be set on the number of SRS symbols that are not transmitted. The SRS-transmitting UE may stop transmitting SRS symbols in the conflicting resource up to the upper limit. For example, when transmitting a four-symbol SRS, the upper limit on the number of SRS transmission symbols stopped in a time and / or frequency resource that collides with a PUSCH may be set to three. In that resource, the SRS-transmitting UE may transmit one SRS symbol. Outside that resource, the SRS-transmitting UE may transmit four SRS symbols. This, for example, enables wideband sounding between the SRS-transmitting UE and the base station while maintaining the PUSCH transmission rate.

[0334] As another example, an upper limit may be set on the number of SRS symbols to be transmitted in the collision. The SRS-transmitting UE may transmit only the upper limit of SRS transmission symbols in the collision resource. For example, in a four-symbol SRS transmission, the upper limit on the number of SRS transmission stop symbols in a time and / or frequency resource that collides with the PUSCH may be set to 1. In that resource, the SRS-transmitting UE may transmit one SRS symbol and stop SRS transmission for three symbols. Outside that resource, the SRS-transmitting UE may transmit four SRS symbols. This makes it possible, for example, to perform sounding between the SRS-transmitting UE and the base station over a wide band while maintaining the PUSCH transmission rate.

[0335] As another example, a constraint may be placed on the number of SRS transmission symbols themselves. For example, when the parameter (DL-DMRS-add-pos) indicating the number of additional DMRSs in a slot in a PUSCH-transmitting UE described in Non-Patent Document 13 (TS38.211 v15.0.0) is 2 or greater, the configurable number of SRS symbols may be set to 1 or 2. The base station may notify the SRS-transmitting UE of the value of this parameter. The SRS-transmitting UE may recognize the constraint on the number of SRS transmission symbols using this parameter. The SRS-transmitting UE may notify the base station of information indicating the occurrence of an irregularity by notifying the base station of the number of SRS transmission symbols that violates the constraint.

[0336] As another example, in a PUSCH-transmitting UE, a constraint may be placed on the parameter indicating the number of additional DMRSs in a slot. For example, if the number of SRS symbols in an SRS-transmitting UE is 4, the value of this parameter in the PUSCH-transmitting UE may be set to 0 or 1. The base station may notify the PUSCH-transmitting UE of the number of SRS transmission symbols in the SRS-transmitting UE. The PUSCH-transmitting UE may recognize the constraint on the parameter value using the notification of the number of SRS transmission symbols. The PUSCH-transmitting UE may notify the base station of information indicating the occurrence of an irregularity by notifying the parameter that violates the constraint.

[0337] The operation regarding the transmission of SRS with multiple symbols may be defined by a standard, or may be determined by the base station and notified or broadcast to the UE. For example, the upper limit of the number of SRS symbols not to be transmitted may be defined by a standard, or may be determined by the base station and notified or broadcast to the UE. The same may be true for the upper limit of the number of SRS symbols to be transmitted and the number of SRS transmission symbols themselves. For example, the base station may use poor channel conditions between the base station and the UE to reduce the upper limit of the number of SRS symbols not to be transmitted. This makes it possible, for example, to ensure the PUSCH transmission rate in the communication system while quickly performing sounding when the channel conditions deteriorate.

[0338] In the above, the notification method and / or the information to be notified may be the same as the notification method and the information to be notified regarding the operation related to SRS transmission of an SRS-transmitting UE in the symbols and frequency band to which PUSCH is allocated.

[0339] Another solution is disclosed. The SRS transmission symbols of the SRS-transmitting UE may be shifted to other timings. Some SRS transmission symbols may be shifted, or the entire SRS transmission symbols may be shifted. This allows, for example, flexible scheduling in the base station.

[0340] The SRS transmission symbols may be shifted within a slot. For example, the symbols of the SRS transmitted by the SRS-transmitting UE may be shifted, the symbols being transmitted in symbols allocated to the reference signals DMRS and / or PTRS associated with the PUSCH. This, for example, enables wideband sounding from the SRS-transmitting UE and improves the demodulation performance of the PUSCH at the base station. As another example, the symbols of the SRS transmitted by the SRS-transmitting UE may be shifted to symbols allocated to the SRS transmitted by a UE different from the SRS-transmitting UE. This, for example, makes it possible to aggregate the number of SRS symbols transmitted from the SRS-transmitting UE and the different UE, thereby improving the PUSCH transmission rate from the PUSCH-transmitting UE.

[0341] The SRS transmission symbols may be shifted only in the PUSCH allocated band, which allows for quick SRS transmission outside the PUSCH allocated band.

[0342] As another example, the entire SRS transmission symbol may be shifted, which may facilitate, for example, control of SRS transmission and reception in a communication system.

[0343] Fig. 19 shows an example in which SRS transmission symbols are shifted only in the PUSCH allocated band. In the example shown in Fig. 19, the subcarrier intervals for PUSCH and SRS are the same. In the example shown in Fig. 19, the PUSCH transmitting UE transmits DMRS 1901 associated with the PUSCH in the second and ninth symbols, and also transmits PTRS 1902 associated with the PUSCH every symbol on two subcarriers. In addition, in the example shown in Fig. 19, the SRS transmitting UE is configured to transmit SRS in the ninth symbol.

[0344] 19 , the SRS-transmitting UE does not transmit SRS in the 9th symbol in the frequency band occupied by the PUSCH 1903 and PTRS 1902 of the PUSCH-transmitting UE, but shifts the SRS transmission in the 9th symbol to the 13th symbol and transmits SRS 1905. Outside this frequency band, the SRS-transmitting UE transmits SRS 1905 in the 9th symbol.

[0345] Figure 20 shows an example of shifting the entire SRS transmission symbol. In Figure 20, the settings for each UE are the same as in Figure 19. In Figure 20, signals that are common to Figure 19 are given the same reference numerals, and common descriptions will be omitted.

[0346] 20, the SRS-transmitting UE shifts the SRS transmission at the 9th symbol to the 13th symbol and transmits SRS 2005. The SRS outside the frequency band occupied by PUSCH 1903 and PTRS 1902 of the PUSCH-transmitting UE is also shifted in the same way.

[0347] As another example of shifting the SRS transmission symbols, the symbols may be shifted to a different slot. The different slot may or may not be adjacent to the original slot. For example, the symbols of the SRS transmitted by the SRS-transmitting UE may be shifted to a slot allocated to an SRS transmitted by a UE other than the SRS-transmitting UE. This makes it possible to aggregate the number of SRS symbols transmitted from the SRS-transmitting UE and the other UE, thereby improving the PUSCH transmission rate from the PUSCH-transmitting UE.

[0348] The SRS transmission symbols for different slots may be shifted only within the PUSCH allocated band, thereby enabling SRS transmission outside the PUSCH allocated band to be performed quickly.

[0349] As another example, the entire SRS transmission symbol may be shifted, which may facilitate, for example, control of SRS transmission and reception in a communication system.

[0350] Figure 21 shows an example in which the SRS transmission symbol is shifted to a different slot only in the PUSCH allocated band. In the example shown in Figure 21, the SRS transmitting UE is configured to transmit the SRS in the 9th symbol of slot number 0. In Figure 21, the configuration of the PUSCH transmitting UE is the same as in Figure 16. In Figure 21, signals that are common to Figure 19 are assigned the same reference numerals, and common explanations will be omitted.

[0351] 21 , the SRS-transmitting UE does not transmit SRS in the 9th symbol of slot number 0 in the frequency band occupied by PUSCH 1903 and PTRS 1902 of the PUSCH-transmitting UE, but shifts the SRS transmission in the 9th symbol of slot number 0 to the 13th symbol of slot number 1 and transmits SRS 2105. Outside this frequency band, the SRS-transmitting UE transmits SRS 2105 in the 9th symbol of slot number 0.

[0352] Figure 22 shows an example in which all SRS transmission symbols are shifted to different slots. In Figure 22, the settings for each UE are the same as in Figure 21. In Figure 21, signals that are common to Figure 19 are given the same reference numerals, and common descriptions will be omitted.

[0353] 22, the SRS-transmitting UE shifts the SRS transmission in the 9th symbol of slot number 0 to the 13th symbol of slot number 1 and transmits SRS 2205. The SRS of the PUSCH-transmitting UE outside the frequency band occupied by PUSCH 1903 and PTRS 1902 is also shifted to slot number 1 in the same manner.

[0354] The shift of the SRS transmission symbol may be defined by a standard, or may be determined by the base station and notified or broadcast to the UE. The notification method may be the same as the notification method regarding the operation of the SRS transmission of the SRS-transmitting UE in the symbol and frequency band to which the PUSCH is allocated.

[0355] The information notified from the base station to the UE regarding the shift of the SRS transmission symbol may be the same as the information (1) to (11) disclosed as the information notified regarding the operation of the SRS transmission of the SRS-transmitting UE in the symbol and frequency band to which the PUSCH is assigned.

[0356] Regarding the information notified from the base station to the UE regarding the shift of the SRS transmission symbol, for example, information (3) to (10) disclosed as information notified regarding the operation of the SRS transmission of the SRS-transmitting UE may include information regarding the SRS before the shift and information regarding the SRS after the shift.

[0357] Information regarding the shift of the SRS transmission symbols notified from the base station to the UE may include information regarding whether or not the SRS transmission symbols are shifted. This allows, for example, the SRS-transmitting UE to easily determine whether or not the SRS transmission symbols are shifted, and as a result, it becomes possible to quickly execute processing regarding the SRS transmission shift.

[0358] The SRS transmission symbol shift may be performed for aperiodic SRS, semi-persistent SRS, or periodic SRS. Furthermore, the SRS transmission symbol shift may be performed when the PUSCH-transmitting UE and the SRS-transmitting UE are the same, or when they are different. A combination of the above may also be applied. For example, when the PUSCH-transmitting UE and the SRS-transmitting UE are different, the aperiodic SRS symbol shift may be performed. This allows, for example, flexible SRS allocation in a communication system.

[0359] The method disclosed in the first embodiment and the method disclosed in the first modification may be used interchangeably, thereby enabling flexible scheduling in a communication system, for example.

[0360] As an example of the aforementioned distinction, the DMRS and / or PTRS associated with the PUSCH transmitted from the PUSCH-transmitting UE may be transmitted in a symbol to which the DMRS and / or PTRS are assigned, or the SRS may be transmitted from the SRS-transmitting UE. For example, when frequency and time resources collide between the aperiodic SRS transmitted from the SRS-transmitting UE and the DMRS or PTRS associated with the PUSCH transmitted from the PUSCH-transmitting UE, the DMRS or PTRS may not be transmitted, and the aperiodic SRS may be transmitted instead. As another example, when it is impossible to assign the DMRS and / or PTRS associated with the PUSCH assigned to the PUSCH-transmitting UE in a symbol following the aperiodic SRS transmitted from the SRS-transmitting UE, the PUSCH may be placed only before the SRS symbol or SRS symbol group. As another example, when a frequency and time resource conflict occurs between a semi-persistent SRS transmitted by an SRS-transmitting UE and a DMRS or PTRS associated with a PUSCH transmitted by a PUSCH-transmitting UE, the semi-persistent SRS transmission symbols from the SRS-transmitting UE may be shifted. The above-described operation may be determined using a use case of the SRS.

[0361] The above-mentioned distinction between the two may be defined by a standard or may be determined by a base station. The base station may broadcast information regarding the distinction between the two or may notify each UE individually. The notification may be performed semi-statically using RRC signaling, dynamically using MAC signaling, or dynamically using DCI.

[0362] As another example, the base station and the UE may each determine which method to use. Information used for the determination may be defined by a standard, or may be determined by the base station. The base station may broadcast information regarding the selection of the method, or may notify the UE individually. The notification may be performed semi-statically using RRC signaling, dynamically using MAC signaling, or dynamically using DCI.

[0363] This first modification makes it possible to ensure a PUSCH transmission rate even when an SRS transmitted from an SRS-transmitting UE and a PUSCH transmitted from a PUSCH-transmitting UE compete for time and / or frequency resources. Furthermore, flexible scheduling becomes possible in the base station, making it possible to avoid interference between the SRS and the PUSCH.

[0364] Variation 2 of Embodiment 1 In the case of PUSCH transmission from a UE, the period from receiving a PDCCH including an uplink grant to transmitting the PUSCH may be different from the period from receiving a PDCCH including an SRS transmission instruction to transmitting the SRS in the case of SRS transmission from a UE. As a result, there may be a collision of time and frequency resources in the PUSCH transmission and SRS transmission from the UE for the PDCCH including an uplink grant and the PDCCH including an SRS transmission instruction, which are transmitted in different slots from the base station. This collision occurs both when the PUSCH transmitting UE and the SRS transmitting UE are the same and when they are different.

[0365] In the above, the scheduling by the PDCCH transmitted later may have priority over the SRS transmission instruction by the PDCCH transmitted earlier. In the above, the PUSCH transmitting UE and the SRS transmitting UE may be the same or different.

[0366] Figure 23 is a diagram showing the operation when PUSCH transmission and SRS transmission from a UE are allocated to the same slot. In the example shown in Figure 23, the PUSCH-transmitting UE and the SRS-transmitting UE are different from each other. In Figure 23, the PUSCH-transmitting UE is referred to as UE #1, and the SRS-transmitting UE is referred to as UE #2.

[0367] In slot #0 shown in FIG. 23, the base station transmits to UE #1 PDCCH 2501 including an uplink grant indicating that PUSCH 2503 is to be transmitted in slot #2. PDCCH 2501 includes information indicating that the transmission of PUSCH 2503 is to be allocated two slots later. In slot #1 shown in FIG. 23, the base station transmits to UE #2 PDCCH 2502 including an instruction to transmit SRS 2504 in slot #2. PDCCH 2502 includes information indicating that the transmission of SRS is to be allocated one slot later.

[0368] In slot #2 shown in FIG. 23, UE #1 transmits PUSCH 2503 and UE #2 transmits SRS 2504. In time and frequency resource 2505 enclosed by a black dotted line in slot #2, UE #1's PUSCH transmission and UE #2's SRS transmission collide. As mentioned above, UE #2's SRS transmission 2504, which is included in the PDCCH transmitted later, takes priority. UE #1 stops transmitting PUSCH 2503 in time and frequency resource 2504.

[0369] The example shown in FIG. 23 illustrates a case where a PDCCH including an uplink grant for a PUSCH is transmitted from a base station before a PDCCH including an SRS transmission instruction. On the other hand, the above-described method may also be applied when a PDCCH including an SRS transmission instruction is transmitted before a PDCCH including an uplink grant for a PUSCH. That is, in slot #0, a PDCCH including an instruction that UE #2 will transmit SRS two slots later is transmitted from the base station, and in slot #1, a PDCCH including an uplink grant that UE #1 will transmit PUSCH one slot later is transmitted from the base station. In this case, PUSCH transmission from UE #1 may be performed in time and frequency resource 2505 in slot #2. UE #2 may stop SRS transmission in time and frequency resource 2505.

[0370] Although an example in which the PUSCH transmitting UE and the SRS transmitting UE are different is shown in FIG. 23, they may be the same.

[0371] In the above, the following problem occurs. That is, when a PUSCH and an SRS are transmitted from different UEs, a PUSCH-transmitting UE that first receives a PDCCH cannot recognize that a PDCCH has been transmitted to another SRS-transmitting UE later. As a result, the PUSCH-transmitting UE cannot stop its own PUSCH transmission during the time and / or frequency resource where the PUSCH and SRS collide, causing interference with the SRS transmitted by the SRS-transmitting UE. As a result, sounding from the SRS-transmitting UE cannot be performed properly.

[0372] In this second modification, a method for solving the above-mentioned problem is disclosed.

[0373] The base station notifies the PUSCH-transmitting UE of information indicating that an SRS transmission instruction has been transmitted to the SRS-transmitting UE.

[0374] For this notification, a PDCCH transmitted individually to the PUSCH-transmitting UE or a PDCCH for group-common signaling may be used. This makes it possible to reduce the amount of signaling, for example, when there are multiple PUSCH-transmitting UEs. As another example, a non-slot PDCCH (i.e., a PDCCH transmitted midway through a slot) may be used. This makes it possible, for example, for the base station to quickly notify the PUSCH-transmitting UE of this information. As another example, a DCI for preemption indication (PI) may be used. This makes it possible, for example, for the UE to perform reception processing of this information with a small amount of processing.

[0375] The PUSCH-transmitting UE may receive information indicating that it has transmitted an SRS transmission instruction to the SRS-transmitting UE. The PUSCH-transmitting UE may receive the information, for example, every slot, or may receive the information at the timing from when the PUSCH-transmitting UE receives a PDCCH including an uplink grant for the PUSCH to when it transmits the PUSCH. The above-mentioned every-slot reception may include the non-slot PDCCH included in each slot. The same may be true for the timing from when the PUSCH-transmitting UE receives a PDCCH including an uplink grant for the PUSCH to when it transmits the PUSCH. For example, by receiving information indicating that an SRS transmission instruction has been transmitted to the SRS-transmitting UE at the above-mentioned timing, it is possible to reduce unnecessary reception operations in the PUSCH-transmitting UE, and as a result, it is possible to reduce power consumption.

[0376] The following items (1) to (5) are disclosed as information included in the notification transmitted from the base station to the PUSCH-transmitting UE.

[0377] (1) Information indicating that another UE will transmit an SRS in a slot granted for PUSCH transmission.

[0378] (2) Information regarding whether and / or how PUSCH is transmitted.

[0379] (3) Information about overlapping frequency and / or time resources between PUSCH and SRS.

[0380] (4) The information (1) to (12) disclosed in the first embodiment as information on SRS transmission resource candidates dynamically notified from the base station to the PUSCH transmission UE.

[0381] (5) A combination of (1) to (4) above.

[0382] The above (1) may be information indicating that another UE transmits an SRS in the time and / or frequency resource to which the PUSCH transmission is granted. This makes it possible to prevent unnecessary suspension of PUSCH transmission, for example, when the PUSCH and the SRS are allocated to the same slot but different time and / or frequency resources. As a result, efficient operation of the communication system is possible.

[0383] The above-mentioned (2) may be, for example, an identifier indicating whether or not to transmit a PUSCH. The PUSCH transmission method in the above-mentioned (2) may be, for example, information indicating that the PUSCH is transmitted with reduced power, information indicating that the PUSCH is transmitted only in a time and / or frequency resource different from that of the SRS, information indicating that the PUSCH is not transmitted, or information indicating that the PUSCH is transmitted as is. The information regarding PUSCH power reduction may include, for example, the amount of power reduction. This enables flexible scheduling in a communication system, for example.

[0384] The above (3) may be, for example, information on both overlapping time and frequency resources, or information on overlapping symbol numbers. The above (3) enables, for example, a PUSCH-transmitting UE to obtain information on time and / or frequency resources for which PUSCH transmission should be avoided, thereby reducing interference between the PUSCH and the SRS.

[0385] A PUSCH-transmitting UE may not transmit the PUSCH in time and / or frequency resources that overlap with the SRS. Alternatively, the UE may transmit the PUSCH in time and / or frequency resources that do not overlap with the SRS. This may, for example, avoid interference between the PUSCH and the SRS while ensuring the PUSCH transmission rate.

[0386] As another example, a PUSCH-transmitting UE may not transmit the PUSCH in symbols that overlap with the SRS, and may transmit the PUSCH in symbols that do not overlap with the SRS, which can, for example, avoid the complexity of avoiding interference between the PUSCH and the SRS.

[0387] As another example, a PUSCH-transmitting UE may not transmit the PUSCH in the entire time and / or frequency resources indicated in the uplink grant, which may further reduce the complexity of interference avoidance between the PUSCH and the SRS, for example.

[0388] Another solution is disclosed. In a communication system, scheduling based on a PDCCH transmitted earlier may be prioritized. In this case, the PUSCH-transmitting UE and the SRS-transmitting UE may be different. This makes it easier to perform scheduling in a base station, for example.

[0389] An SRS-transmitting UE may not transmit SRS. The base station may not transmit a PDCCH instructing SRS transmission to the SRS-transmitting UE. As another example, an SRS-transmitting UE may not transmit SRS only in time and / or frequency resources overlapping with a PUSCH. The base station may notify the SRS-transmitting UE of an instruction not to transmit SRS in those resources. This instruction may be included in the PDCCH containing the SRS transmission instruction, or may be notified at a different timing. As another example, an SRS-transmitting UE may transmit SRS with reduced transmission power.

[0390] The following items (1) to (5) are disclosed as information included in the notification transmitted from the base station to the SRS-transmitting UE.

[0391] (1) Information indicating that another UE will transmit a PUSCH in the slot in which the SRS is transmitted.

[0392] (2) Information about whether and / or how SRS is transmitted.

[0393] (3) Information about overlapping frequency and / or time resources between PUSCH and SRS.

[0394] (4) The information (1) to (11) disclosed in the first modification of the first embodiment as information to be notified from the base station to the SRS-transmitting UE.

[0395] (5) A combination of (1) to (4) above.

[0396] The above (1) may be information indicating that PUSCH transmission of another UE is to be performed at the time and / or frequency resource instructed for SRS transmission. This makes it possible to prevent unnecessary SRS transmission suspension, for example, when PUSCH and SRS are assigned to the same slot but different time and / or frequency resources. As a result, efficient operation of the communication system is possible.

[0397] The above-mentioned (2) may be, for example, an identifier indicating whether or not to transmit SRS. The SRS transmission method in the above-mentioned (2) may be, for example, information indicating that the SRS is transmitted with reduced power, information indicating that the SRS is transmitted only in a time and / or frequency resource different from that of the PUSCH, information indicating that the SRS is not transmitted, or information indicating that the SRS is transmitted as is. Information regarding SRS power reduction, for example, the amount of power reduction, may also be included. This enables, for example, flexible sounding in a communication system.

[0398] The above (3) may be, for example, information on both overlapping time and / or frequency resources, or information on overlapping symbol numbers. The above (3) enables, for example, an SRS-transmitting UE to obtain information on time and / or frequency resources on which SRS transmission should be avoided, thereby reducing interference between the PUSCH and the SRS.

[0399] Another solution will be disclosed. In this second modification, the operation of giving priority to a PDCCH transmitted later and the operation of giving priority to a PDCCH transmitted earlier may be combined.

[0400] For example, the base station may decide which PDCCH to prioritize. The base station may notify the UE of information on which PDCCH to prioritize. The UE may use the information to transmit or not transmit the PUSCH and / or SRS. For the notification, for example, RRC signaling, MAC signaling, or L1 / L2 signaling may be used.

[0401] As another example, which PDCCH has priority may be determined by a standard, which may eliminate the need for a base station to notify a UE of information regarding which PDCCH has priority, thereby reducing the amount of signaling from the base station to the UE.

[0402] The information used to determine which PDCCH to prioritize may be the use case of the SRS or the type of SRS (e.g., periodic SRS, semi-persistent SRS, aperiodic SRS).

[0403] The information used to determine which PDCCH to prioritize may be the use case of the SRS, the type of SRS (e.g., periodic SRS, semi-persistent SRS, aperiodic SRS), or both.

[0404] As another example of the information, information about the PUSCH may be used. For example, information about the service (e.g., eMBB, URLLC, mMTC) of user data transmitted on the PUSCH may be used, or information about the priority of the user data, for example, priority information determined by a QCI (QoS Class Identifier), may be used. This enables flexible scheduling according to the priority of user data, for example.

[0405] The method of prioritizing PDCCHs disclosed in this Modification 2 may be applied when the PUSCH-transmitting UE and the SRS-transmitting UE are the same. The information notified from the base station to the UE may be a combination of the information disclosed in this Modification 2.

[0406] For example, if the same UE transmits a PUSCH and an SRS, the SRS resource and the PUSCH resource may collide within the same slot. In this case, a priority defined by the standard may be applied. Several examples of priority may be assumed. For example, if a UE receives multiple PDCCHs for SRS and PUSCH transmission at different times, the PUSCH or SRS resource set by the last transmitted PDCCH may be prioritized. Priority may also be determined based on the type of SRS. For example, if a non-periodic SRS and a PUSCH resource collide, the non-periodic SRS may be prioritized. When a base station needs to quickly obtain transmission path information, it requests the UE to transmit a non-periodic SRS. Therefore, by transmitting the non-periodic SRS with priority over the PUSCH, the base station can obtain the transmission path information within the desired time. Furthermore, if the SRS and PUSCH resources partially overlap, the above-described priority may be applied only to the overlapping portion. In other words, only a portion of the SRS or PUSCH is transmitted. As another example, the standard may set a priority such that DMRS included in PUSCH has priority over SRS, regardless of the type of SRS.

[0407] For example, if the PUSCH transmitting UE and the SRS transmitting UE are the same and the SRS and PUSCH resources partially overlap, there are no restrictions on the relative positions of the SRS and PUSCH. The SRS may be transmitted before or after the PUSCH. The order of the SRS is determined by the contents of the PUSCH. If time is required to process the PUSCH transmission, the SRS may be transmitted first. Conversely, if the data contained in the PUSCH needs to be transmitted urgently, the PUSCH may be sent earlier in the slot, and the transmission of the SRS may be delayed.

[0408] The method disclosed in this modification 2 may be applied to cases where the numerologies of the PUSCH and the SRS are different. This makes it possible to reduce the delay from receiving a PDCCH including an SRS transmission instruction to transmitting the SRS, for example, when the subcarrier spacing of the SRS is large.

[0409] When using PI, a base station transmits a PI to a PUSCH-transmitting UE or an SRS-transmitting UE, and the UE that receives the PI prioritizes the designated interval for SRS or PUSCH transmission by other UEs. The designated interval is defined by time or frequency resources. Specifically, a UE that receives the PI reduces its power during the designated interval to avoid interfering with the transmission signals of other UEs. The designated interval may be specified by a standard on a symbol-by-symbol basis, or may be dynamically specified via the PI. When a standard specifies an interval, it may be specified as the last X symbols in a slot, where X is an integer. Furthermore, if the slot format of an SRS- or PUSCH-transmitting UE is a minislot, the UE that receives the PI may reduce the transmission power of all symbols in the minislot that is the target of collision. An example of reducing the transmission power is to set the transmission power to zero. After collision is avoided, transmission in the minislot proceeds as normal.

[0410] Note that whether SRS transmission or PUSCH transmission is prioritized may be determined by a standard. For example, the priority may be determined based on the type of SRS or the type of RS included in the PUSCH. For example, aperiodic SRS may always be transmitted with priority over PUSCH. In other words, if aperiodic SRS and PUSCH collide, the aperiodic SRS always takes priority, and a PI is sent from the base station to the PUSCH-transmitting UE. As another example, a priority may be set in a standard such that a DMRS included in PUSCH takes priority over an SRS, regardless of the type of SRS. In this case, a PI is transmitted to the SRS-transmitting UE, and the transmission power of the section colliding with the DMRS or the minislot in which the SRS is transmitted may be reduced. Note that after collision is avoided, transmission of the minislot is performed as usual, and the transmission power may be reduced and no retransmission of resources may be performed.

[0411] A UE that receives a PI may reduce the transmission power of the slot or minislot that is Y slots or Y minislots after the slot or minislot in which the PI was received, where Y is an integer. In the above example, the transmission power was adjusted after counting in slot or minislot units, but it may also be counted in symbol units. For example, the symbol Y symbols after the symbol containing the PI may be the first symbol, and if Z is an integer, the transmission power of Z symbols may be reduced.

[0412] The PI may be placed in a symbol and frequency region specified by the standard within a slot or minislot. By placing the PI at a specified time and frequency location, a UE that receives the PI can quickly decode it.

[0413] In this Modification 2, an example has been disclosed in which a PDCCH including an SRS transmission instruction to an SRS-transmitting UE is transmitted from a base station after a PDCCH including an uplink grant to a PUSCH-transmitting UE. The method disclosed in this Modification 2 may also be applied to a case in which a PDCCH including an SRS transmission instruction is transmitted before a PDCCH including an uplink grant for a PUSCH. In the above case, the method disclosed in this Modification 2 may be applied by replacing SRS and PUSCH.

[0414] Modification 2 makes it possible to reduce interference between the PUSCH and the SRS. Furthermore, even when the subcarrier intervals of the PUSCH and the SRS are different, it becomes possible to transmit the PUSCH or the SRS with low delay.

[0415] Modification 3 of Embodiment 1 The same problems as those in the first embodiment to the second embodiment occur with respect to the PUCCH transmitted from a PUCCH-transmitting UE and the SRS transmitted from an SRS-transmitting UE. That is, if a collision occurs between the PUCCH and the SRS in the time and / or frequency resources allocated to the PUCCH and the SRS, the PUCCH and the SRS interfere with each other, and the base station is unable to receive the PUCCH and the SRS normally.

[0416] In this third modification, a solution to the above problem is disclosed.

[0417] A channel or signal for collision avoidance is provided. The base station determines whether collision occurs between the SRS and the PUCCH. This determination may be made for each slot, or may not be made for slots in which no scheduling occurs.

[0418] The base station transmits a channel or signal for collision avoidance (hereinafter, sometimes referred to as a collision avoidance instruction) to the UE. The UE may be a UE for which it is desired to avoid transmitting a PUCCH or an SRS. The UE may be an SRS transmitting UE, a PUCH transmitting UE, or both.

[0419] The UE uses the collision avoidance instruction to stop transmission of the PUCCH or SRS. The PUCCH may be a long PUCCH, i.e., a PUCCH of four or more symbols, or a short PUCCH, i.e., a PUCCH of two or less symbols. Transmission of the PUCCH or SRS may be stopped entirely or partially in the target slot. Partial stopping may mean, for example, stopping transmission in a symbol where a collision occurs between the PUCCH and the SRS, or stopping transmission in the time and / or frequency resources where the collision occurs. This allows, for example, efficient use of time and / or frequency resources in the communication system.

[0420] The collision avoidance instruction may be included as DCI in a PDCCH transmitted to each UE individually, or may be transmitted in a PDCCH for group-wide signaling. As another example, the collision avoidance instruction may be transmitted in a preemption indication. As another example, the collision avoidance instruction may be transmitted in RRC signaling or in MAC signaling.

[0421] Figure 24 is a diagram showing the operation of collision avoidance between SRS and PUSCH in response to a collision avoidance instruction sent from a base station. The example of Figure 24 shows a case where the base station sends a collision avoidance instruction to an SRS-transmitting UE, and the SRS-transmitting UE does not transmit SRS in the slot shown in Figure 24. In Figure 24, the subcarrier spacing between PUCCH and SRS is the same. In the example shown in Figure 24, the PUCCH-transmitting UE transmits PUCCH 3005 in the 12th and 13th symbols. Also, in the example shown in Figure 24, the SRS-transmitting UE is configured to transmit SRS in time and frequency resource 3006 of the 13th symbol.

[0422] 24, the base station notifies the SRS-transmitting UE of collision avoidance command 3001. The SRS-transmitting UE does not transmit SRS in the 13th symbol in response to collision avoidance command 3001. As a result, PUCCH 3005 is not subjected to interference from the SRS.

[0423] Figure 25 is a diagram showing the operation of collision avoidance between SRS and PUCCH in response to a collision avoidance instruction sent from a base station. The example in Figure 25 shows a case where a base station sends a collision avoidance instruction to an SRS-transmitting UE, and the SRS-transmitting UE does not transmit SRS in the time and frequency resources that collide with PUCCH in the slot shown in Figure 25. In Figure 25, the settings for each UE are the same as in Figure 24. In Figure 25, signals that are common to Figure 24 are assigned the same reference numerals, and common descriptions will be omitted.

[0424] 25, an SRS-transmitting UE transmits an SRS 3101 in response to a collision avoidance command 3001 transmitted from the base station. The SRS is not transmitted in a time or frequency resource where a collision with the PUCCH occurs. This prevents interference with the SRS on the PUCCH 3005, and also enables sounding between the base station and the SRS-transmitting UE.

[0425] Figure 26 is a diagram showing another example of the operation of avoiding collision between SRS and PUCCH in response to a collision avoidance instruction sent from a base station. The example in Figure 26 shows a case where a base station sends a collision avoidance instruction to a PUCCH-transmitting UE, and the PUCCH-transmitting UE does not transmit a long PUCCH at the 13th symbol. In Figure 26, the subcarrier intervals for PUCCH and SRS are the same. In the example shown in Figure 26, the PUCCH-transmitting UE is configured to transmit a long PUCCH at the 7th to 13th symbols. Also, in the example shown in Figure 26, the SRS-transmitting UE is configured to transmit an SRS at the 13th symbol.

[0426] 26, the base station notifies the PUCCH transmitting UE of collision avoidance command 3201. In response to collision avoidance command 3201, the PUCCH transmitting UE transmits long PUCCH 3205 in the 7th to 12th symbols, but does not transmit PUCCH in the 13th symbol. In the 13th symbol, the SRS transmitting UE transmits SRS 3206. This prevents long PUCCH 3205 and SRS 3206 from interfering with each other.

[0427] In collision avoidance in the third modification, a transmission priority order may be set. The priority order may be statically determined by a standard or the like, or may be determined by a base station. The priority order may be determined using the quality required for the PUCCH and SRS, or the operation type of the PUCCH and SRS. The required quality may be, for example, information related to QoS. The operation type of the PUCCH and SRS may be, for example, a periodic PUCCH, a semi-persistent PUCCH, or an aperiodic PUCCH, or may be a periodic SRS, a semi-persistent SRS, or an aperiodic SRS. Using the above, for example, an aperiodic PUCCH may take priority over a periodic SRS or a semi-persistent SRS, or an aperiodic SRS may take priority over a periodic PUCCH or a semi-persistent PUCCH. As another example, a periodic PUCCH or a semi-persistent PUCCH may take priority over a periodic SRS or a semi-persistent SRS, or vice versa. As another example, aperiodic PUCCH may take precedence over aperiodic SRS, or vice versa.

[0428] As another example of determining the priority, the timing set by the base station may be used. The operation of determining the priority using the timing set by the base station may be applied to, for example, aperiodic PUCCH and / or aperiodic SRS instructed to transmit by a PDCCH from the base station. For example, a PUCCH instructed to transmit by a PDCCH transmitted later from the base station may be given priority over an SRS instructed to transmit by a PDCCH transmitted earlier from the base station. In the above, the PUCCH and SRS may be reversed. This, for example, makes it possible to avoid complexity in designing scheduling in a communication system.

[0429] As another example of determining the priority, the transmission content included in the PUCCH may be used. For example, a PUCCH including a scheduling request (SR) may be prioritized over an SRS, a PUCCH including HARQ feedback may be prioritized over an SRS, or an SRS may be prioritized over a periodic CSI report or a semi-persistent CSI report. The above priorities may also be reversed. This allows, for example, a base station to perform flexible scheduling based on the content included in the PUCCH.

[0430] Another example of prioritization is the use case of SRS, where SRS for antenna switching may take priority over PUCCH, allowing the UE to quickly perform antenna switching, for example.

[0431] As another example of determining the priority, information regarding the symbol length of the PUCCH may be used. For example, SRS may be prioritized over long PUCCHs, i.e., PUCCHs with four or more symbols, or short PUCCHs, i.e., PUCCHs with two or less symbols, may be prioritized over SRS. In the above, symbols of the long PUCCH that were not transmitted may be restored by error correction in the base station. This makes it possible, for example, to perform sounding by transmitting an SRS from an SRS-transmitting UE while ensuring the reliability of the PUCCH transmitted from the PUCCH-transmitting UE. As a result, the communication system can be operated efficiently.

[0432] As another example of determining the priority, whether or not the PUCCH symbol that conflicts with the SRS is a DMRS associated with the PUCCH may be used. For example, if the conflicting symbol is the DMRS, the DMRS may be prioritized over the SRS, or if not, the SRS may be prioritized over the PUCCH. The aforementioned PUCCH may be, for example, a long PUCCH. This makes it possible to ensure the demodulation performance of the long PUCCH in the base station.

[0433] In the above, information on whether or not the symbol is an additional DMRS may be used. For example, if the colliding symbol is not an additional DMRS, the PUCCH may take priority over the SRS, or if the colliding symbol is an additional DMRS, the SRS may take priority over the PUCCH. The PUCCH may be, for example, a long PUCCH. This makes it possible to perform sounding by transmitting an SRS from an SRS-transmitting UE while ensuring the demodulation performance of the long PUCCH in the base station.

[0434] When symbols of a DMRS and an SRS associated with a PUCCH collide, the symbols of the DMRS may be shifted. For example, the method disclosed in the first embodiment may be applied to the shift. As another example, the collision avoidance command may include information regarding the shift of the DMRS. The information may include information regarding the time and / or frequency resources after the DMRS is shifted, or information regarding the time and / or frequency resources before the DMRS is shifted.

[0435] The base station uses the priority determined above to notify the UE of a collision avoidance instruction for which it wishes to avoid transmitting a PUCCH or SRS. The UE performs a PUCCH or SRS transmission process in accordance with the instruction included in the instruction. As another example, the UE stops transmitting a PUCCH or SRS.

[0436] The collision avoidance instruction includes the following items (1) to (7).

[0437] (1) Information on collision avoidance methods.

[0438] (2) Information about conflicting resources.

[0439] (3) Information regarding changes or resetting of transmission timing.

[0440] (4) Information regarding changes or reconfigurations of transmission frequency resources.

[0441] (5) Information regarding the SRS to be stopped from being transmitted.

[0442] (6) Information about the PUCCH for which transmission is to be stopped.

[0443] (7) A combination of (1) to (6) above.

[0444] The above (1) may be, for example, stopping the transmission of PUCCH or SRS in a slot, or stopping the transmission of only collision symbols. The above (1) may be information on rate matching when stopping the transmission of only collision symbols, for example, information on whether rate matching is performed.

[0445] As another example, the above (1) may be information indicating that the transmission timing is to be changed or reset, or information indicating that the transmission frequency is to be changed or reset, or a combination of the above two.

[0446] The above (1) makes it possible to flexibly avoid collisions between PUCCH and SRS in a communication system, for example.

[0447] The above (2) may include, for example, information about the slot number. Information about the colliding symbols, such as the collision start symbol, the number of collision symbols, the collision end symbol, or a combination of two or more of the above, may be included in the above (2). The information about the colliding symbols may be, for example, information based on a combination of symbol numbers. The above symbol numbers may be absolute numbers from the beginning of the slot, or may be relative numbers from a predetermined position. As another example, a bitmap may be provided, and each bit of the bitmap may be associated with each symbol. The bit length included in the bitmap may be 14 or less than 14. When the bit length is less than 14, for example, the last bit may be associated with the last symbol of the slot.

[0448] As another example, the above (2) may be information about RB numbers. The information about RB numbers may include, for example, a collision start symbol, a collision symbol number, a collision end symbol, or a combination of two or more of the above. As another example, information based on a combination of RB numbers may be used. The above RB numbers may be absolute RB numbers from the first RB of the BWP used by the UE, or may be relative numbers from a predetermined position. As another example, a bitmap may be provided, and each bit of the bitmap may be associated with each RB.

[0449] The information in (3) above may be information about the changed or reset transmission timing, or may include information about the original transmission timing. The information about the transmission timing may be the same as that in (2) above.

[0450] The information in (4) above may be information about the changed or reset transmission frequency resource, or may include information about the original transmission frequency resource. The information about the transmission timing may be the same as that in (2) above.

[0451] The above (5) may be information indicating the number of slots from the collision avoidance command to the SRS at which transmission is stopped, or may be an identifier of the SRS setting.

[0452] The above (6) may be information indicating the number of slots from the collision avoidance command to the PUCCH where transmission is stopped, or may be an identifier of the PUCCH setting.

[0453] Another solution will be disclosed. The base station may notify or broadcast information related to the SRS settings of the UEs under its control to the PUCCH-transmitting UE in advance. The method disclosed in the first embodiment may be applied to the notification or broadcast. This provides the same effect as in the first embodiment. In the above, SRS and PUCCH may be reversed. The method disclosed in the first embodiment may be applied by replacing SRS and PUCCH. This provides the same effect as in the above.

[0454] Another solution will be disclosed. The base station schedules in advance the SRS transmitted from an SRS-transmitting UE and the PUCCH transmitted from a PUCCH-transmitting UE so that the time and / or frequency resources do not collide. The UE may not perform any special operation in the resources where the SRS and / or PUCCH are scheduled. The UE may not receive the collision avoidance instruction disclosed in this third modification. This, for example, makes it possible to avoid design complexity in the UE.

[0455] In the above, for example, the base station may configure the SRS to exclude a frequency band in which the PUCCH may be transmitted. As another example, the base station may configure the transmission frequency of the PUCCH to a frequency resource at the edge of the BWP.

[0456] If SRS is stopped to avoid collision between PUCCH and SRS, problems may occur such as the base station being unable to measure uplink channels or manage beams.

[0457] A solution to the above problem is disclosed. The base station can configure an SRS-transmitting UE to transmit another SRS in a slot where the SRS has been stopped due to a collision with the PUCCH. The other SRS may be, for example, an aperiodic SRS. Information regarding the configuration may be included in the same downlink control information (DCI) as the collision avoidance instruction, for example. The information regarding the configuration may be, for example, an identifier of the aperiodic SRS. The SRS-transmitting UE may use the configuration to transmit an aperiodic SRS instead of the SRS whose transmission has been stopped.

[0458] This third modification makes it possible to avoid collisions between PUCCH and SRS, thereby improving the robustness of the communication system.

[0459] Embodiment 2 A UE is configured by a higher layer to use all or part of the DL band and / or all or part of the UL band. These configured bands are called BWP (BandWidth Part). A BWP is configured for each serving cell, and communication is performed within the range of the configured BWP. A BWP configured in DL is called DL-BWP. A BWP configured in UL is called UL-BWP.

[0460] The gNB configures one or more BWP candidates for the UE. This configuration is performed by higher layer signaling. The gNB notifies the UE of the BWP that will actually perform communication from among the BWP candidates. The BWP that actually performs communication is called the active BWP. This configuration is performed by higher layer signaling, L1 / L2 signaling, or MAC signaling.

[0461] It has been proposed to use measurement gaps as a method for UEs to transmit SRS in bands outside the range of an active UL-BWP (see Reference 22 (R1-1715277)). Measurement gaps are periods set to measure the received power and reception quality of DL signals at different frequencies. This raises the question of how to transmit SRS, which is an UL signal, using measurement gaps. However, no disclosure has been made regarding this method. Therefore, UEs cannot transmit SRS in bands outside the range of an active BWP using measurement gaps.

[0462] In the second embodiment, a method for solving such a problem will be disclosed.

[0463] The gNB notifies the UE of the configuration of the SRS to be transmitted during the measurement gap period. The configuration of the SRS to be transmitted during the measurement gap period may include the resource on the frequency axis for transmitting the SRS, or the resource on the time axis for transmitting the SRS.

[0464] The transmission band of the SRS to be transmitted during the measurement gap period should be set so that it does not include the active BWP. This allows the SRS to be transmitted in a band outside the range of the active BWP.

[0465] As another method for setting the transmission bandwidth of the SRS to be transmitted during the measurement gap period, the SRS transmission bandwidth may be set to include the active BWP. By setting the SRS transmission bandwidth not only outside the range of the active BWP but also including the active BWP, the SRS transmission bandwidth can be set without excluding the band of the active BWP, regardless of where the active BWP is set. This makes it easy to set the SRS transmission bandwidth.

[0466] The UE may be configured not to transmit SRS in the active BWP during the measurement gap period. The UE may also be configured not to transmit SRS in the active BWP in the SRS transmission band set during the measurement gap period. Typically, the UE is configured to transmit SRS separately in the active BWP. Therefore, for example, by omitting SRS transmission in the active BWP, it is possible to reduce the transmission band of the SRS transmitted by the UE. This also makes it possible to reduce the power consumption of the UE.

[0467] The UE may be configured to transmit the SRS in the active BWP during the measurement gap period. The UE may also be configured to transmit the SRS in the active BWP, which is one of the SRS transmission bands configured during the measurement gap period. Regardless of where the active BWP is configured, the transmission band of the SRS transmitted by the UE can be set without excluding the band of the active BWP. This makes it easy to set the SRS transmission band.

[0468] Multiple SRSs may be configured for one measurement gap. For example, SRSs may be configured to be transmitted at multiple times in one measurement gap. The multiple SRSs may be configured for different frequency bands. This enables, for example, wideband sounding in one measurement gap. This allows wideband sounding to be performed quickly. Furthermore, SRSs may be configured using multiple measurement gaps. The SRSs configured for each measurement gap in multiple measurement gaps may be different. For example, even when the measurement gap duration is short and the UL band is wide, using multiple measurement gaps makes it possible to transmit SRSs over the entire UL band.

[0469] When configuring the SRS to be transmitted during the measurement gap, the transmission band of the SRS may be arbitrarily set regardless of the DL band measured at the same timing as the UE transmits the SRS.

[0470] Furthermore, the measurement gaps for setting the SRS may be limited to measurement gaps for DL ​​measurements of carrier frequencies in the same band, rather than measurement gaps for DL ​​measurements of carrier frequencies in a different band.The measurement gaps for setting the SRS may be limited to measurement gaps for measurements after changing the carrier frequency in DL measurements of carrier frequencies in the same band or changing the band within the same carrier frequency.

[0471] Furthermore, the measurement gaps for setting the SRS may be limited to measurement gaps for DL ​​measurements of the same carrier frequency, rather than measurement gaps for DL ​​measurements of a different carrier frequency.The measurement gaps for setting the SRS may be limited to measurement gaps for measurements with a change in bandwidth or frequency band in DL measurements of the same carrier frequency.

[0472] This restriction allows the UE to be configured with a correlation between the receiving frequency and the transmitting frequency, making it possible to manufacture the UE easily and inexpensively.

[0473] A method for notifying information regarding the configuration of an SRS to be transmitted during a measurement gap period is disclosed. A gNB semi-statically configures an SRS to be transmitted during a measurement gap period for a UE. For example, the SRS may be configured according to the use case of the SRS. The gNB semi-statically notifies the UE of information regarding the configuration of an SRS to be transmitted during a measurement gap period. RRC signaling may be used for the notification. The UE that receives the notification transmits an SRS during the measurement gap period using the information regarding the SRS configuration.

[0474] The gNB may notify the UE of the start, change, or end of configuration of the SRS to be transmitted during a measurement gap period. It may also notify an offset period until the SRS configuration is started. It may also notify the period from the start to the end of the SRS configuration. The period from the start to the end of the SRS configuration may be managed by a timer. The SRS configuration may be terminated upon expiration of the timer. After the SRS configuration is terminated, the UE may not transmit the SRS during a measurement gap period. It may also set the period from the start to the end of the SRS configuration as the number of measurement gaps. The gNB may notify the UE of the number of measurement gaps.

[0475] The gNB may notify the UE that it will stop transmitting SRS during a predetermined measurement gap. For example, the gNB may notify the UE that it will stop transmitting SRS prior to the measurement gap in which it is desired to stop transmitting SRS. The number of measurement gaps in which SRS transmission is stopped may be one or more. In this way, it is possible to reduce unnecessary SRS transmission. It is also possible to reduce interference with transmissions from other UEs.

[0476] Another notification method is disclosed. The gNB configures the UE with the SRS to be transmitted during the measurement gap period for each measurement gap. Since the SRS can be configured for each measurement gap, flexible and timely configuration is possible. The gNB notifies the UE of information regarding the configuration of the SRS to be transmitted during the measurement gap period prior to the measurement gap. This notification may be notified by L1 / L2 signaling. This notification may be included in DCI and notified on the PDCCH. This enables rapid notification.

[0477] The notification may be sent by MAC signaling. The notification may be sent by including it in MAC CE. This enables retransmission control, thereby improving reliability. The notification may be sent by RRC signaling. This allows more information to be sent. For example, it enables flexible setting of the SRS band, etc. The UE that receives the notification transmits SRS using information related to the SRS setting during the measurement gap period.

[0478] The UE may notify the base station of a response to the notification. The notification may be notified by RRC signaling. By notifying the response, it is possible to further improve reliability. The notification may also be notified by MAC signaling. Alternatively, it may be notified by L1 / L2 signaling. This allows for a quick response.

[0479] The gNB may not send the UE the configuration of the SRS to be transmitted during the measurement gap. In this case, the gNB may not transmit the SRS during the measurement gap. In this way, the gNB can prevent the UE from transmitting the SRS during the measurement gap in which the gNB does not want the UE to transmit the SRS.

[0480] The above-mentioned methods for setting the SRS to be transmitted during the measurement gap period may be used in combination, allowing for flexible SRS transmission settings.

[0481] Examples of information regarding SRS settings are shown below (1) to (8).

[0482] (1) Information about SRS transmission band.

[0483] (2) Information regarding the timing of SRS transmission.

[0484] (3) Information on SRS numerology.

[0485] (4) Information about the sequence of the SRS.

[0486] (5) Information indicating whether SRS is to be transmitted within the active BWP.

[0487] (6) SRS setting ID.

[0488] (7) Information about the SRS port number.

[0489] (8) A combination of (1) to (7).

[0490] Regarding (1), the information about the SRS transmission band is information for identifying the SRS transmission band. Examples of this information include the following (1-1) to (1-5).

[0491] (1-1) First PRB number.

[0492] (1-2) Ending PRB number.

[0493] (1-3) PRB number.

[0494] (1-4) Information indicating the frequency hopping band.

[0495] (1-5) Combination of (1-1) to (1-4).

[0496] Regarding (2), the information about the SRS transmission timing is information for specifying the SRS transmission timing. Examples of this information include the following (2-1) to (2-7).

[0497] (2-1) Slot number.

[0498] (2-2) Symbol number.

[0499] (2-3) Start slot number, which may be an offset.

[0500] (2-4) Start symbol number, which may be an offset.

[0501] (2-5) Number of symbols.

[0502] (2-6) Period.

[0503] (2-7) A combination of (2-1) to (2-6).

[0504] Regarding (3), the information on the numerology of the SRS is information for identifying the numerology of the SRS. Examples of this information include the following (3-1) to (3-5).

[0505] (3-1) SCS (subcarrier spacing).

[0506] (3-2) Symbol duration.

[0507] (3-3) ID that identifies the numerology.

[0508] (3-4) Information indicating whether the numerology of the SRS is the same as the numerology of the active BWP.

[0509] (3-5) A combination of (3-1) to (3-4).

[0510] Regarding (3-3), the ID specifying the numerology may be, for example, a number assigned in advance to each numerology. The ID specifying the numerology may be statically determined in advance by a standard or the like, or may be semi-statically notified from the gNB to the UE by RRC signaling. The numerology of the SRS may be set to the same as the numerology set in the band in which the SRS is transmitted. In this way, the gNB can cause the UE to transmit the SRS using the same numerology as the actual uplink transmission. This makes it possible to improve the accuracy of uplink sounding.

[0511] If the information in (3-4) is set so that the SRS numerology is the same as the numerology of the active BWP, the numerology switching time in the UE can be shortened. In this case, the ID specifying the numerology in (3-3) may be omitted. This reduces the amount of information that needs to be notified. If the information is set so that the SRS numerology is different from the numerology of the active BWP, the ID specifying the numerology in (3-3) may be used to set the numerology set in the band transmitting the SRS. This allows for flexible setting of the numerology used for the SRS.

[0512] Regarding (4), the information about the SRS sequence is information for identifying the SRS sequence. Examples of the information include the following (4-1) to (4-5).

[0513] (4-1) SRS sequence ID.

[0514] (4-2) Cyclic shift.

[0515] (4-3) Comb value.

[0516] (4-4) Comb offset.

[0517] (4-5) A combination of (4-1) to (4-4).

[0518] Regarding (5), the information indicating whether to transmit SRS in the active BWP is the information for the UE to set whether to transmit SRS in the active BWP during the measurement gap period, as described above.

[0519] Regarding (6), the SRS configuration ID is an identifier for identifying this SRS configuration. The SRS configuration identifier may be assigned as a number for each cell, or may be assigned as a number for each UE or UE group. Furthermore, the SRS ID may include information indicating the time domain behavior of the SRS. For example, this information may indicate whether the SRS is periodic, semi-persistent, or aperiodic.

[0520] Regarding (7), the information regarding the port number of the SRS is information for identifying the port number for transmitting the SRS.

[0521] Information regarding SRS configuration may be combined and configured. For example, a different transmission band may be set for each SRS transmission symbol. As another example, SRS transmission may be configured to be performed using multiple symbols, and a different transmission band may be set for each of the multiple symbols. For example, SRS transmission for such multiple symbols may be configured as a single set. In this way, by combining and configuring information regarding SRS configuration, flexible and diverse SRS transmission configurations can be implemented.

[0522] The SRS transmission timing may be set to be included in the measurement gap period. This allows for settings appropriate for DL ​​measurement timing. Furthermore, by aligning the SRS transmission timing with the DL measurement timing, it is possible to eliminate or minimize the timing difference between DL measurement and SRS transmission. DL measurement and UL sounding can be performed with low latency. Since DL measurement and UL sounding can be performed close to each other, the communication quality of both DL and UL at that timing can be obtained.

[0523] The timing of the measurement gap may be set in accordance with the SRS transmission setting. The measurement gap may be set to include the timing when the SRS transmission is set. This allows for settings suitable for UL sounding.

[0524] Fig. 27 is a diagram showing an example of SRS transmission configuration during a measurement gap period in the second embodiment. Fig. 27 shows a method of semi-statically notifying the SRS transmission configuration. Fig. 27 shows a case where SRS is transmitted outside the range of an active BWP. The horizontal axis indicates time, and the vertical axis indicates frequency. The frequency axis direction indicates the entire UL frequency band. 4101 and 4106 indicate measurement gap periods. 4102, 4103, 4104, 4105, 4107, 4108, 4109, and 4110 are resources configured for SRS transmission, and the UE transmits SRS using the shaded resources and does not transmit SRS using the white resources.

[0525] The black arrows on the time axis indicate SRS configuration from the gNB to the UE. The gNB notifies the UE of information regarding SRS configuration. This notification is, for example, semi-statically transmitted by RRC signaling. The information regarding SRS configuration includes resource information 4102, 4103, 4104, and 4105. Periodicity information may also be included in the information regarding SRS configuration. The example in FIG. 27 shows that SRS configuration for 4102, 4103, 4104, and 4105 is performed periodically according to the periodicity information. Therefore, SRS is configured in 4107, 4108, 4109, and 4110.

[0526] Furthermore, the information regarding the SRS configuration may include information indicating whether to transmit within an active BWP. In the example of Fig. 27, it is assumed that the SRS is not transmitted within an active BWP. The UE does not transmit the SRS within the active BWP during the measurement gap period.

[0527] Using the received SRS configuration information, the UE transmits SRS in the configured resources 4102, 4103, 4104, and 4105 in the measurement gap 4101. However, since the UE is configured not to transmit SRS in the active BWP, the UE does not transmit SRS within the range of the active BWP of resources 4104 and 4105 where SRS transmission is configured.

[0528] The active UL-BWP may be switched between the measurement gap 4101 and the next measurement gap 4106. As indicated by the white arrow, the gNB switches the active UL-BWP for the UE. The UE switches the active BWP.

[0529] Using the received SRS configuration information, the UE transmits SRS in the configured resources 4107, 4108, 4109, and 4110 in the next measurement gap 4106. However, since the UE is configured not to transmit SRS in the active BWP, the UE does not transmit SRS within the range of the active BWP of resources 4107 and 4108 where SRS transmission is configured.

[0530] This allows the UE to transmit SRS outside the range of the active BWP.

[0531] Fig. 28 is a diagram showing an example of SRS transmission settings during a measurement gap period in the second embodiment. Fig. 28 shows a method for dynamically notifying the SRS transmission settings. Fig. 28 shows a case where SRS is transmitted outside the range of an active BWP. Reference numerals 4201 and 4204 indicate measurement gap periods. Reference numerals 4202, 4203, 4205, and 4206 indicate resources configured for SRS transmission, and the UE transmits SRS using the shaded resources.

[0532] The black arrow on the time axis indicates the SRS configuration from the gNB to the UE. The gNB notifies the UE of information regarding the SRS configuration. This notification is, for example, dynamically notified by L1 / L2 signaling. This notification is notified for each measurement gap, in advance of the measurement gap. It becomes possible to notify the SRS configuration for each measurement gap. It becomes possible to change the SRS configuration for each measurement gap, making it possible to configure SRS transmission accordingly.

[0533] In the SRS configuration notified before the measurement gap 4201, the information about the SRS configuration includes resource information 4202 and 4203. In the SRS configuration notified before the measurement gap 4204, the information about the SRS configuration includes resource information 4205 and 4206.

[0534] By dynamically notifying the SRS configuration, it is possible to configure the SRS resource according to the active BWP configuration. For example, if you do not want to transmit SRS within the active BWP, you can configure the SRS transmission resource outside the active BWP. By configuring in this way, the UE does not transmit SRS in the active BWP during the measurement gap period.

[0535] The UE transmits SRS in the measurement gap 4201 on pre-configured resources 4202, 4203 of the measurement gap 4201. Switching of the active UL-BWP may occur between the measurement gap 4201 and the next measurement gap 4204. As indicated by the white arrow, the gNB switches the active UL-BWP for the UE. The UE switches the active BWP.

[0536] The UE transmits SRS in the measurement gap 4204 using pre-configured resources 4205 and 4206 of the measurement gap 4204. In this way, the UE can transmit SRS outside the range of the active BWP. In addition, the gNB dynamically notifies the UE of information regarding SRS configuration, making it possible to configure SRS for each measurement gap. This allows the gNB to flexibly configure SRS transmission for the UE at the timing when sounding is required.

[0537] The semi-static and dynamic methods of configuring SRS transmission may be combined. The gNB configures part of the SRS transmission settings for the UE semi-statically and the other parts dynamically. The gNB notifies the UE of part of the information related to the SRS transmission settings semi-statically and the other parts dynamically. This reduces the amount of information to be dynamically notified.

[0538] The gNB may notify the UE of SRS transmission configuration candidates using measurement gaps. The candidate may be one or more. The gNB may notify the UE which SRS transmission configuration to use from the candidate. The notification method may be the same as the above-mentioned method. For example, the SRS transmission configuration candidates may be notified by RRC signaling, and which SRS transmission configuration to use from the candidate may be notified by MAC signaling.

[0539] This allows for flexible SRS transmission settings and reduces the amount of information that is dynamically notified.

[0540] A method for transmitting an SRS (UL) using a measurement gap for DL ​​measurements has been disclosed. Another method will be disclosed. A period is provided for transmitting an UL signal or UL channel outside the range of an active BWP. Hereinafter, this is referred to as a UL transmission gap. The measurement gap for DL ​​measurements and the UL transmission gap may be different. During the UL transmission gap, the gNB does not schedule UL transmissions to the UE using the active UL-BWP. During the UL transmission gap, the UE does not need to transmit using the active UL-BWP.

[0541] The UL signal transmitted by the UE outside the active BWP may be an SRS. The gNB may provide the UE with an UL transmission gap for transmitting the SRS outside the active BWP. During the UL transmission gap, the UE transmits the SRS outside the active BWP.

[0542] DL communication may be performed during the UL transmission gap. DL measurements may also be performed during the UL transmission gap. The gNB may schedule DL transmissions for the UE during the UL transmission gap. The UE may receive DL during the UL transmission gap. The DL transmissions may be performed with an active DL-BWP. The UE receives the active DL-BWP.

[0543] The gNB may notify the UE of the SRS transmission configuration in an active DL-BWP. The gNB may also notify the UE of the SRS transmission configuration during a UL transmission gap in an active DL-BWP. In this way, by differentiating the UL transmission gap from the measurement gap for DL ​​measurements, the gNB can notify the UE of the SRS transmission configuration during a UL transmission gap. This enables more dynamic SRS transmission configuration.

[0544] The SRS may be set by applying the method described above.

[0545] This section describes a method for setting UL transmission gaps. The gNB notifies the UE of information about UL transmission gaps. Examples of information about UL transmission gaps are shown below (1) to (5).

[0546] (1) Gap period.

[0547] (2) The period of the gap, which may be a repeating period.

[0548] (3) Gap offset.

[0549] (4) Gap setting identifier.

[0550] (5) A combination of (1) to (4).

[0551] The duration, cycle, and offset of the gap may each be in units of a radio frame, a subframe, a slot, a minislot, or a symbol, or may be in units of a time such as milliseconds.

[0552] The gNB may also notify the UE of the start, change, or end of setting a UL transmission gap. The gNB may also notify the UE of an offset period until the start of setting the UL transmission gap. The gNB may also notify the UE of the period from the start to the end of setting the UL transmission gap. The period from the start to the end of setting the UL transmission gap may be managed by a timer. The expiration of the timer may be the end of setting the UL transmission gap. The period from the start to the end of setting the UL transmission gap may also be set by the number of UL transmission gaps. The gNB may notify the UE of the number of UL transmission gaps.

[0553] 29 is a diagram showing an example of setting up an SRS transmission gap by providing an UL transmission gap. Reference numeral 4301 denotes a transmission gap. The setting of the UL transmission gap is notified in advance from the gNB to the UE.

[0554] Furthermore, the gNB notifies the UE of SRS configuration before the UL transmission gap. The black arrow on the time axis indicates SRS configuration from the gNB to the UE. The gNB notifies the UE of information regarding SRS configuration. This notification is, for example, dynamically notified by L1 / L2 signaling. 4302 and 4303 are resources configured for SRS transmission, and the UE transmits SRS using the shaded resources.

[0555] By providing a gap for UL transmission in this way, uplink transmission is possible regardless of the measurement gap for DL ​​measurement. For example, uplink transmission is possible outside the range of the active UL-BWP regardless of the timing for DL ​​measurement. SRS transmission is also possible as uplink transmission. Therefore, uplink transmission can be performed at the timing when uplink transmission is required.

[0556] Figure 30 shows another example of configuring SRS transmission by providing a UL transmission gap. Figure 30 shows a method in which a gNB notifies a UE of SRS configuration during a UL transmission gap period. 4401 indicates a UL transmission gap. The gNB notifies the UE in advance of the UL transmission gap configuration.

[0557] The gNB notifies the UE of the SRS configuration during the UL transmission gap period. The black arrow on the time axis indicates the SRS configuration from the gNB to the UE. The gNB notifies the UE of information regarding the SRS configuration. This notification is, for example, dynamically notified by L1 / L2 signaling. 4402 and 4403 are resources configured for SRS transmission, and the UE transmits the SRS using the shaded resources.

[0558] SRS configuration is performed in DL. Therefore, by setting the UL transmission gap to a different period from the measurement gap for DL ​​measurements, the gNB can notify the UE of the SRS configuration during the UL transmission gap. This allows the gNB to more flexibly and timely configure SRS transmission settings for the UE when sounding is required.

[0559] Figure 31 is a diagram showing a specific example of setting SRS transmission by providing a UL transmission gap. Figure 31 shows a method of notifying SRS setting during a UL transmission gap period. The horizontal axis represents time, and the vertical axis represents frequency. The upper diagram shows DL, and the lower diagram shows UL. The frequency axis direction of the upper diagram shows the active DL-BWP range. The frequency axis direction of the lower diagram shows the entire UL frequency band.

[0560] A PUSCH is transmitted in the period from 4509 to 4513 and the period from 4514 to 4516 by an active UL-BWP in the UL. A UL transmission gap is configured between 4513 and 4514. The UL transmission gap is configured by the gNB notifying the UE in advance of the setting of the UL transmission gap. The UE does not perform UL transmission by an active UL-BWP in the UL transmission gap.

[0561] This shows the SRS transmission method. 4502, 4504, 4506, and 4508 are resources configured for SRS transmission. SRS transmission is configured outside the active UL-BWP range. In an active DL-BWP in the downlink, the gNB notifies the UE of information regarding the SRS transmission configuration. Here, it is shown that notification is made by L1 / L2 signaling. The information is included in DCI and notified on the PDCCH.

[0562] The UE notifies DCI4501 including information about the setting of SRS4502. The UE notifies DCI4503 including information about the setting of SRS4504. The UE notifies DCI4505 including information about the setting of SRS4506. The UE notifies DCI4507 including information about the setting of SRS4508. The UE transmits SRS outside the active UL-BWP range during the UL transmission gap period using the SRS configuration received from the gNB.

[0563] In this way, by notifying the SRS transmission setting by the active DL-BWP during the UL transmission gap period, the gNB can more flexibly configure the SRS transmission setting for the UE when sounding is required. In addition, the gNB can schedule the SRS transmission setting for the UE taking into account the PUSCH transmission of other UEs.

[0564] A measurement gap may be provided only for DL. UL signals and UL channels can be transmitted during this measurement gap. The transmission of these UL signals and UL channels is performed using an active UL-BWP. When a measurement gap is provided only for DL, a problem occurs in that PUSCH scheduling cannot be performed during this measurement gap. A method for solving this problem is disclosed.

[0565] The gNB schedules the PUSCH to the UE before the DL-only measurement gap period. The gNB schedules the PUSCH to the UE before the DL-only measurement gap period instead of scheduling the PUSCH during the DL-only measurement gap period. The UE transmits the PUSCH using the PUSCH scheduling information notified before the DL-only measurement gap period.

[0566] The gNB may notify the UE of the scheduling information of the PUSCH via DCI. The scheduling of the PUSCH can be dynamically configured before the DL-only measurement gap period.

[0567] As another method, the gNB may notify the UE of the scheduling information of the PUSCH via MAC. In order to prevent retransmission control from affecting the measurement gap, it is preferable to notify the scheduling information of the PUSCH before the maximum number of retransmissions. In this way, reception errors at the UE can be reduced, and malfunctions can be reduced.

[0568] Alternatively, the gNB may notify the UE of the scheduling information of the PUSCH by RRC signaling. This notification may be performed separately from the configuration of the DL-only measurement gap, or may be performed together with the configuration of the DL-only measurement gap. This makes it possible to further reduce reception errors at the UE.

[0569] As with the PUSCH, the gNB may schedule the PUCCH for transmitting SR or HARQ-Ack, or the aperiodic SRS or semi-persistent PUCCH to the UE before the DL-only measurement gap period. This allows the UE to transmit the signals or channels using the scheduling information for the signals or channels notified before the DL-only measurement gap period.

[0570] When a downlink-only measurement gap is configured, transmission of an UL signal or UL channel configured by periodic or semi-persistent scheduling, or transmission without an uplink grant, may be performed.

[0571] The method for setting the DL-only measurement gap may be the same as the method for setting the UL transmission gap. The setting of the DL-only measurement gap may be different from the setting of the UL transmission gap. These settings may be set separately. By setting them separately, uplink transmission does not need to follow the DL measurement timing, and uplink transmission can be performed at the timing required for UL transmission.

[0572] FIG. 32 is a diagram showing a specific example of a DL-only measurement gap. The horizontal axis indicates time, and the vertical axis indicates frequency. The upper diagram shows DL, and the lower diagram shows UL. The frequency axis direction of the upper diagram shows the active DL-BWP range. The frequency axis direction of the lower diagram shows the entire UL frequency band. A DL-only measurement gap is configured in an active DL-BWP. The gNB notifies the UE in advance of the configuration of a DL-only measurement gap, thereby configuring the DL-only measurement gap. The UE does not perform DL reception using an active DL-BWP in the DL-only measurement gap.

[0573] Figure 32 shows a case where a UE is scheduled to continuously transmit a PUSCH in an active UL-BWP. 4602 to 4609 indicate PUSCHs. The gNB cannot perform UL scheduling for the UE during a DL-only measurement gap. Therefore, the gNB schedules a PUSCH for the UE before the DL-only measurement gap.

[0574] For example, the gNB includes PUSCH scheduling information in DCI 4601 and notifies the UE. UL scheduling information for multiple slots may be included in the DCI. The UE transmits PUSCHs 4604, 4605, 4606, and 4607 during DL-only measurement gap periods using the PUSCH scheduling information received from the gNB.

[0575] In this way, even when a measurement gap is provided only for DL, it is possible to schedule the PUSCH during the measurement gap period only for DL. Therefore, the UE can transmit the PUSCH even during the measurement gap period only for DL.

[0576] In TDD, the active UL-BWP switches in sync with the active DL-BWP switching. The active DL-BWP also switches in sync with the active UL-BWP switching. When transmitting SRS outside the active BWP range using a measurement gap, SRS transmission may be performed at the DL center frequency or frequency band measured in the measurement gap.

[0577] This makes it possible to perform UL sounding at the center frequency or frequency band expected to be used in DL. The center frequency or frequency band used for communication can be set according to both the DL reception power and communication quality and the UL communication quality. The gNB can set such a center frequency or frequency band for the UE. This allows for a setting that takes both DL and UL into consideration.

[0578] When UL SRS transmission is set to a center frequency or frequency band different from the DL center frequency or frequency band measured in the DL measurement gap, the above-described method cannot be implemented. A method for solving this problem is disclosed.

[0579] Provide multiple measurement gaps. Provide multiple measurement gaps from the gNB to the UE. It is advisable to apply some of the multiple measurement settings for DL ​​measurements and others for UL transmission. SRS transmission may be performed during the measurement gap period for UL transmission. The gNB configures a measurement gap for UL transmission for the UE and configures SRS transmission during the measurement gap period for UL transmission.

[0580] It is preferable to set each measurement gap separately for multiple measurement gaps. The setting method for each measurement gap can be the same as the setting method for UL transmission gaps described above. The setting method for UL transmission gaps described above can be applied to both measurement gaps for DL ​​measurements and measurement gaps for UL transmission.

[0581] Each measurement gap may be set to be discrete or continuous in time. Furthermore, each measurement gap may be set according to the timing of DL measurement and / or UL transmission. For example, if a slot format is set in which the first 0 to 8 symbols are DL, the 9 to 11 symbols are unknown, and the 12 to 13 symbols are UL, then the first 0 to 8 symbols may be set as measurement gaps for DL ​​measurement, and the 12 to 13 symbols may be set as measurement gaps for UL transmission.

[0582] Alternatively, multiple consecutive slots may be used as one measurement gap. For example, the first 0 to 8th symbols of each of 10 consecutive slots may be set as measurement gaps for DL ​​measurements. Alternatively, the 12th to 13th symbols of 10 consecutive slots may be set as measurement gaps for UL transmission.

[0583] Symbols set as unknown in a slot may be set as measurement gaps for DL ​​measurements and / or measurement gaps for UL transmission.

[0584] The measurement gaps may be configured to not overlap in time. The UE operates as if the measurement gaps do not overlap in time. If the measurement gaps overlap in time, the UE may disable these measurement gaps.

[0585] Alternatively, if the UE receives a configuration in which measurement gaps overlap, the UE may prioritize DL measurement for the overlapping portion. Alternatively, if the UE receives a configuration in which measurement gaps overlap in time, the UE may prioritize UL transmission for the overlapping portion. These priorities may be statically determined by a standard or may be semi-statically notified from the gNB to the UE via RRC signaling.

[0586] When multiple measurement gaps are set, measurement gaps for DL ​​measurements and measurement gaps for UL transmissions may be set alternately.

[0587] Although the setting of multiple measurement gaps has been disclosed, an alternative method is to set a DL measurement interval and a UL transmission interval in one measurement gap. The duration of each interval can be set. The setting of each interval can be performed using the setting method for UL transmission gaps.

[0588] When the gNB pre-configures DL transmission timing for a UE, a UE group, or a cell in general, a measurement gap for DL ​​measurement may be provided at the DL transmission timing. Similarly, when the gNB pre-configures UL transmission timing for a UE, a UE group, or a cell in general, a measurement gap for UL transmission may be provided at the UL transmission timing. Furthermore, a DL measurement interval may be provided at the DL transmission timing. Furthermore, a UL transmission interval may be provided at the UL transmission timing.

[0589] The DL measurement configuration for the DL measurement gap period may be performed before the DL measurement gap period. The gNB may notify the UE in advance of the measurement configuration for the DL measurement gap period. This allows the UE to perform DL measurements during the DL measurement gap period.

[0590] The SRS transmission setting for transmission during the UL transmission measurement gap period can be configured using the SRS setting method described above, which enables the UE to transmit the SRS during the UL transmission measurement gap period.

[0591] Figure 33 shows an example of setting multiple measurement gaps in TDD. The horizontal axis represents time, and the vertical axis represents frequency. The frequency axis direction shows the entire DL or UL frequency band. Also, this shows a case where the active DL-BWP and the active UL-BWP are the same.

[0592] In Figure 33, two measurement gaps are set. One is a measurement gap for DL ​​measurements and the other is a measurement gap for UL transmission. Figure 33 shows a case where the measurement gap for DL ​​measurements and the measurement gap for UL transmission are separated in time.

[0593] Reference numeral 4701 denotes a measurement gap for DL ​​measurement, and 4704 denotes a measurement gap for UL transmission. The settings of these measurement gaps are configured in advance by the gNB to the UE. The settings of the measurement gap for DL ​​measurement and the measurement gap for UL transmission may be different.

[0594] DL measurement is performed in DL measurement gap 4701. The black arrow before DL measurement gap 4701 on the time axis indicates DL measurement configuration from the gNB to the UE. The gNB notifies the UE of the DL measurement configuration before the DL measurement measurement gap. This notification may be performed, for example, by RRC signaling. 4702 and 4703 indicate resources for DL ​​measurement notified in the DL measurement configuration. The UE performs DL measurement in 4702 and 4703, which are outside the range of the active DL-BWP.

[0595] Switching between the active DL-BWP and the active UL-BWP may occur between the DL measurement gap 4701 and the UL transmission measurement gap 4704. As indicated by the white arrow, the gNB switches between the active DL-BWP and the active UL-BWP for the UE. The UE switches between the active DL-BWP and the active UL-BWP.

[0596] UL transmission is performed in UL transmission measurement gap 4704. The black arrow before UL transmission measurement gap 4704 on the time axis indicates SRS configuration from the gNB to the UE. The gNB notifies the UE of the SRS transmission configuration before the DL measurement measurement gap. This notification may be performed, for example, by L1 / L2 signaling. 4705 and 4706 indicate resources for SRS transmission notified in the SRS transmission configuration. The UE transmits SRS in 4705 and 4706, which are outside the range of the active UL-BWP.

[0597] In this way, by configuring the DL measurement gap and the UL transmission measurement gap, not only DL measurement but also SRS transmission can be performed outside the active BWP range even in TDD. By configuring the DL measurement gap and the UL transmission measurement gap at different times, for example, it becomes possible to dynamically configure the SRS just before the UL transmission measurement gap.

[0598] Figure 34 shows another example of setting multiple measurement gaps in TDD. Here, two measurement gaps are set. One is a measurement gap for DL ​​measurements, and the other is a measurement gap for UL transmission. Figure 34 shows a case where the measurement gap for DL ​​measurements and the measurement gap for UL transmission are continuous in time.

[0599] Reference numeral 4801 denotes a measurement gap for DL ​​measurement, and 4804 denotes a measurement gap for UL transmission. These measurement gaps are configured in advance by the gNB to the UE.

[0600] DL measurements are performed in the DL measurement gap 4801. The black arrow before the DL measurement gap 4801 on the time axis indicates the configuration of DL measurements and SRS transmission from the gNB to the UE. The gNB notifies the UE of the configuration of DL measurements and SRS transmission before the DL measurement gap. Different signaling may be used for the notification. For example, the configuration of DL measurements may be performed by RRC signaling, and the configuration of SRS transmission may be performed by L1 / L2 signaling.

[0601] Alternatively, the same signaling may be used for DL ​​measurement configuration and SRS transmission configuration. For example, the gNB may notify the UE of the DL measurement configuration and SRS transmission configuration using the same RRC signaling. This reduces the amount of signaling.

[0602] Reference numerals 4802 and 4803 indicate resources for DL ​​measurement notified in the DL measurement configuration. These resources 4802 and 4803 are set as measurement gap periods for DL ​​measurement. Reference numerals 4805 and 4806 indicate resources for SRS transmission notified in the SRS transmission configuration. These resources 4805 and 4806 are set as measurement gap periods for UL transmission. A UE that has received the DL measurement configuration performs DL measurement using 4802 and 4803, which are outside the range of an active DL-BWP. A UE that has received the SRS transmission configuration transmits SRS using 4805 and 4806, which are outside the range of an active UL-BWP.

[0603] In this way, by setting the DL measurement gap and the UL transmission measurement gap consecutively in time, for example, by notifying the DL measurement setting and the SRS setting in a single signaling, the amount of signaling can be reduced. Also, by reducing the time difference between DL measurement and UL transmission, it becomes possible to perform DL measurement and UL sounding in approximately the same time.

[0604] The aforementioned measurement gap, UL transmission gap, DL measurement measurement gap, and UE transmission measurement gap may be used for DL ​​communication or UL communication in a beam different from the beam used for data communication. For example, a measurement gap may be used for DL ​​measurement in a beam different from the beam used for DL ​​data communication. For example, a UL transmission gap may be used for UL transmission in a beam different from the beam used for UL data communication. Since DL measurement and SRS transmission can be performed in a beam different from the beam used for data communication, it is possible to obtain the DL and UL communication quality between beams. The gNB enables communication with the UE using a more optimal beam.

[0605] According to the measurement gap method disclosed in the second embodiment, the UE can perform transmission outside the active BWP range. Also, the UE can transmit SRS outside the active BWP range. By transmitting SRS outside the active BWP range from the UE, the gNB can evaluate the uplink communication quality outside the active BWP range. This allows the gNB to set a more suitable frequency band as the BWP for the UE.

[0606] Embodiment 3 To transmit SRS outside the range of an active BWP, BWP switching may be used. The gNB performs BWP switching for the UE. In this way, the UE can transmit SRS in the switched BWP.

[0607] However, conventional BWP switching can only be performed among a maximum of four BWPs preset by the gNB to the UE. This causes a problem that in the UL frequency band, the UE cannot transmit SRS at frequencies outside the range of the preset BWP. This causes a problem that frequencies occur at which UL sounding by SRS is not possible. In this third embodiment, a method for solving such a problem is disclosed.

[0608] The gNB pre-configures the frequency at which the SRS is to be transmitted as a BWP for the UE. The gNB then notifies the UE of the BWP configuration. In this way, the BWP is configured at the frequency at which the UE transmits the SRS, and the UE can transmit the SRS by switching to the BWP.

[0609] Another method is disclosed. The gNB pre-configures a BWP for the UE, which covers the entire UL frequency band. By doing so, the UE can transmit SRS on any UL frequency by switching to the BWP.

[0610] However, because such a method configures a BWP for UL sounding, it reduces the number of configurable BWPs (BWPs for communications other than UL sounding) that can be used for communications other than UL sounding, such as conventional BWPs. For example, if the entire UL frequency band is wideband and the frequency band supported by the UE is narrowband, it is necessary to configure a large number of BWPs for communications other than UL sounding. However, reducing the number of configurable BWPs reduces the frequency band available for communication, which leads to a deterioration in communication quality between the gNB and the UE.

[0611] Furthermore, when the UL frequency band includes multiple numerologies, a BWP must be provided for each numerology, making it impossible to set a BWP that covers the entire UL frequency band.

[0612] A method for solving this problem is disclosed below. The maximum number of BWPs that can be configured is increased. The maximum value of four is set taking into consideration the number of BWPs used for communications other than UL sounding. Therefore, it is advisable to increase the maximum number taking into consideration the use of BWPs for UL sounding as well. For example, the number required to sound the entire UL frequency band can be calculated from the lowest frequency band supported by the UE and the entire UL frequency band, and the maximum value can be set by adding four to that value.

[0613] The maximum number of BWP configurations may be statically determined by standards, etc. Alternatively, the gNB may configure the maximum number of BWP configurations for each UE or for each UE group. The UE may also notify the gNB of the maximum number of BWP configurations that it can support. The gNB may configure BWP for the UE using the maximum value of the supportable BWP configurations notified by the UE.

[0614] By doing this, even if a BWP for UL sounding is configured, the number of BWPs that can be configured for communications other than UL sounding will not be reduced, which maintains the flexibility of BWP switching and reduces the degradation of communication quality between the gNB and the UE.

[0615] However, even if the maximum number of BWP settings is increased, the following problems may occur. The method of pre-setting the frequency for transmitting SRS as a BWP requires that the BWP setting be changed to match the SRS transmission frequency each time the frequency for transmitting SRS is changed. Even if the BWP setting used for communications other than UL sounding remains unchanged, the BWP setting set for the UE must be changed. This leads to an increase in the amount of signaling information required for pre-setting the BWP between the gNB and the UE.

[0616] Furthermore, the method of setting a BWP that covers the entire UL frequency band requires the UE to support the entire UL frequency band, which leads to increased UE power consumption, more complex circuit configuration, and higher manufacturing costs.

[0617] A method for solving such problems is disclosed.

[0618] A BWP for UL sounding is provided. A BWP for SRS transmission may also be provided. Hereinafter, the BWP for UL sounding is referred to as the sounding BWP. It is preferable to configure the sounding BWP separately from the BWP used for communications other than UL sounding. In this way, the gNB does not need to notify the UE of information about the configuration of the BWP used for communications other than UL sounding every time it changes the frequency for transmitting SRS. This makes it possible to suppress an increase in the amount of signaling information required for the BWP configuration from the gNB to the UE.

[0619] One or more BWPs are configured as a sounding BWP. The gNB configures one or more BWPs for the UE. One or more sounding BWPs may be configured as a set. For example, some of the sounding BWP settings may be the same for a set of sounding BWPs. In such cases, it is advisable to configure the settings common to the set of sounding BWPs separately from the settings for each sounding BWP. By providing a common setting for a set of sounding BWPs, the amount of information that needs to be signaled to the UE can be reduced.

[0620] The setting of the sounding BWP may be changed each time an SRS is transmitted, allowing an appropriate sounding BWP to be set and enabling SRS to be transmitted in that sounding BWP.

[0621] Multiple sounding BWP settings may be switched and used. The gNB notifies the UE which sounding BWP to use from the multiple sounding BWPs that have been set. This eliminates the need to notify the sounding BWP setting every time an SRS is transmitted, thereby reducing the amount of signaling.

[0622] In this way, the sounding BWP in which the UE can transmit SRS may be set as the active sounding BWP.

[0623] There may be frequency overlap between sounding BWPs. This improves sounding reliability. Alternatively, sounding BWPs may be configured so that there is no frequency overlap between them. For example, if the entire UL frequency band is used as the sounding frequency, fewer sounding BWPs can be configured, which reduces the number of SRS transmissions by the UE.

[0624] The frequency bandwidth of the BWP may be the same between sounding BWPs. This simplifies control since the UE does not need to change the bandwidth each time the sounding BWP is changed. Alternatively, the frequency bandwidth of the BWP may be different between sounding BWPs. This allows for flexible setting of the frequency bandwidth required for SRS transmission.

[0625] SRS is transmitted within the range of the sounding BWP. The gNB configures the UE to transmit SRS within the range of the sounding BWP. The frequency band of the sounding BWP may be the same as the SRS transmission band. Alternatively, the frequency band of the sounding BWP may be configured to transmit SRS in one SRS transmission. In this way, it becomes possible to use the sounding BWP for transmitting SRS.

[0626] Although the SRS transmission in the sounding BWP has been disclosed, the sounding BWP may have the same functions as or some of the functions of the BWP for communications other than sounding. For example, the UE may be able to transmit not only the SRS but also a specified UL signal and UL channel in the sounding BWP. For example, the HARQ Ack / Nack response to the PDSCH may be transmitted in the sounding BWP. This allows the HARQ response to be transmitted early without waiting for the sounding BWP period to end, thereby achieving lower latency.

[0627] The method for setting the sounding BWP is disclosed. The following (1) to (7) are disclosed as information on setting the sounding BWP.

[0628] (1) Sounding BWP Identifier.

[0629] (2) SCS (Sub-Carrier Spacing).

[0630] (3) CP (Cyclic Prefix).

[0631] (4) Number of PRBs.

[0632] (5) PRB number.

[0633] (6) Sounding BWP duration.

[0634] (7) A combination of (1) to (6).

[0635] (1) may be an identifier to identify the set sounding BWP.

[0636] Regarding (2), instead of the SCS, the symbol interval may be used, or an identifier for identifying the numerology may be used.

[0637] Regarding (3), an identifier for identifying the CP may be used instead of the CP value.

[0638] Instead of (5), the number of the first PRB of the BWP may be used. Alternatively, the smallest PRB number may be used. By using the number of PRBs in (4) and the first PRB number, it is possible to identify the frequency band in which the BWP is set.

[0639] Regarding (6), the time may be in units of radio frames, subframes, slots, minislots, or symbols. Alternatively, it may be in units of milliseconds or other time units. By notifying the sounding BWP duration as information when the sounding BWP is set, it becomes unnecessary to notify the duration each time the sounding BWP is switched. This makes it possible to reduce the amount of signaling.

[0640] The gNB configures the sounding BWP by notifying the UE of information related to the sounding BWP configuration. The UE configures the sounding BWP using the sounding BWP information notified by the gNB. RRC signaling may be used as a notification method. Information related to the sounding BWP may be notified individually to a UE, for each UE group, or for each cell. In the case of notification for each cell, information related to the sounding BWP may be broadcast by being included in broadcast information.

[0641] The sounding BWP setting may be statically determined in advance by a standard, etc. This makes it possible to reduce the amount of signaling.

[0642] The gNB notifies the UE that it will switch to the sounding BWP. The gNB may perform the switch by selecting the next sounding BWP to be used from one or more sounding BWPs configured for the UE. The switch may be performed from a BWP for communications other than sounding to the sounding BWP, or between sounding BWPs. The gNB notifies the UE of information for the switch. Upon receiving the information for the switch, the UE switches to the sounding BWP in accordance with the information. Examples of information for the switch are shown below in (1) to (6).

[0643] (1) Information indicating a switch to sounding BWP.

[0644] (2) Identifier of the sounding BWP after switching.

[0645] (3) Timing of starting sounding BWP.

[0646] (4) Sounding BWP duration.

[0647] (5) Timing of end of sounding BWP.

[0648] (6) A combination of (1) to (5).

[0649] The information in (1) allows the UE to explicitly recognize that it is switching to a sounding BWP. The UE can recognize that this is different from an instruction to switch to a BWP for communication other than sounding. This reduces the occurrence of malfunctions.

[0650] It is advisable to distinguish the identifier of the sounding BWP in (2) from the identifier of the BWP for communication other than sounding. In this case, if the information in (2) is available, the information in (1) can be omitted. Also, it is not necessary to distinguish the identifier of the sounding BWP from the identifier of the BWP for communication other than sounding. Identifiers of the same series may be used. In this way, it is possible to use the same identifier for both the sounding BWP and the BWP for communication other than sounding, thereby reducing the number of identifiers to be prepared.

[0651] (3) to (5) are information about the sounding BWP setting period, which may be in units of radio frames, subframes, slots, minislots (non-slots), or symbols, or may be in units of milliseconds or other time.

[0652] The information for switching may be notified for each UE individually, for each UE group, or for each cell. In the case of notification for each cell, the information for switching may be included in broadcast information and broadcast. RRC signaling may be used as a method for notifying the information for switching. MAC signaling may also be used as another notification method. This allows for quick implementation from notification to switching.

[0653] As another notification method, L1 / L2 signaling may be used. Information for switching may be included in DCI and notified on the PDCCH. For example, when notifying for each UE group, the group-common PDCCH may be used. By using L1 / L2 signaling, the process from notification to switching can be carried out even more quickly.

[0654] It has been disclosed that the sounding BWP may be switched in units of minislots or symbols. This enables more timely and flexible switching of the sounding BWP and transmission of SRS in that BWP. The active DL-BWP and / or active UL-BWP used for communications other than sounding may be switched in units of minislots or symbols. This enables more timely and flexible switching of the frequency band for transmitting PDSCH or PUSCH. It becomes possible to use frequency bands with better communication quality in smaller time units.

[0655] The gNB may notify the UE of only the switching of the sounding BWP. The gNB may notify the UE of only information for switching the sounding BWP. A DCI format solely for switching the sounding BWP may be provided. When such a DCI format is configured for each UE individually, the UE receives the PDCCH using the RNTI configured for each UE. When a DCI format is configured for each UE group, the UE receives the PDCCH using the RNTI configured for each UE group. When a DCI format is configured for each cell, the UE receives the PDCCH using the RNTI configured for each cell.

[0656] It has been disclosed that a DCI format may be provided solely for switching the sounding BWP. A DCI format may also be provided solely for switching the active BWP for communications other than sounding. For example, if you want to transmit only SRS in a BWP for communications other than sounding, scheduling information for other channels is not required.

[0657] By doing this, there is no need to include other information in the DCI, and the amount of signaling information can be reduced.

[0658] The DCI format used for switching BWPs for communications other than sounding may be used for switching the sounding BWP. Information indicating BWP switching may be applied to switching BWPs for communications other than sounding and the sounding BWP. In addition to the information indicating BWP switching, information indicating the identifier of the sounding BWP or the identifier of the BWP for communications other than sounding may be added.

[0659] When switching from a sounding BWP to a BWP for communications other than sounding, information indicating switching to an active BWP may be included in DCI and transmitted over the PDCCH. The DCI format used for switching BWPs for communications other than sounding may also be used.

[0660] As another method, it may be statically determined in advance by a standard or the like that after the sounding BWP configuration period expires, the previously configured BWP for communication other than sounding is restored. Information about the sounding BWP configuration period is set as information about sounding BWP switching. Upon receiving the sounding BWP switching information, the UE restores the previously configured BWP for communication other than sounding after the sounding BWP configuration period expires in accordance with the information about the sounding BWP configuration period.

[0661] The sounding BWP setting period may be managed by a timer. After the timer expires, the UE returns to the previously configured BWP setting for communication other than sounding. By managing the setting period suitable for the sounding BWP by a timer, the gNB can ensure that the UE transmits SRS outside the active BWP range.

[0662] The sounding BWP setting period may be statically determined in advance by a standard, etc. Since it is no longer necessary to include information about the sounding BWP setting period in information about sounding BWP switching and notify it to the UE, the amount of information to be signaled can be reduced.

[0663] In this way, it is not necessary for the gNB to notify the UE of the switch from the sounding BWP to the BWP for communications other than sounding, and therefore the amount of signaling can be reduced. Also, since the setting of the BWP for communications other than sounding that was set immediately before is restored, it is possible to restore the previous communication quality state even when transitioning to the sounding BWP setting period. Therefore, good communication quality can be maintained and the occurrence of radio link failures can be reduced.

[0664] FIG. 35 is a diagram showing an example in which a sounding BWP is provided. The vertical axis represents the UL frequency band. The sounding BWP is set separately from the BWP used for communications other than UL sounding. The gNB sets the sounding BWP and the BWP used for communications other than UL sounding separately and notifies the UE of the settings. This notification may be made, for example, by RRC signaling.

[0665] The gNB may configure the UE with a sounding BWP in accordance with the SRS transmission setting in the UL frequency set in advance. The gNB may also configure the UE with SRS transmission settings in each sounding BWP. These SRS transmission settings may be configured by applying the method disclosed in the second embodiment as appropriate. In this way, the gNB can cause the UE to transmit SRS in the sounding BWP.

[0666] As another method, the gNB may configure the UE to transmit SRS in accordance with the configured sounding BWP. Alternatively, the gNB may configure the UE to transmit SRS in each sounding BWP. These SRS transmission configurations may be performed by applying the method disclosed in the second embodiment as appropriate. In this way, the gNB can cause the UE to transmit SRS in the sounding BWP.

[0667] As another method, the gNB may configure the UE with a sounding BWP that includes the entire UL frequency band. Alternatively, the gNB may configure the UE to transmit SRS in each sounding BWP. The method disclosed in the second embodiment may be applied as appropriate to these SRS transmission configurations. In this way, the gNB can cause the UE to transmit SRS in the sounding BWP over the entire UL frequency band.

[0668] Alternatively, the UE may switch to a sounding BWP depending on the SRS transmission configuration in a pre-configured UL frequency. For example, the UE may determine the sounding BWP to switch to based on the SRS transmission configuration.

[0669] As another example, the relationship between the SRS transmission setting and the sounding BWP used for the SRS transmission may be set in advance. For example, the gNB may set the sounding BWP to be used for each SRS transmission setting in advance and notify the UE. The UE may then determine the sounding BWP to switch to in accordance with the setting. RRC signaling, MAC signaling, or L1 / L2 signaling may be used to notify the setting. Furthermore, the setting may be notified together with the SRS transmission setting and / or the sounding BWP setting. This eliminates the need for notification when switching between sounding BWPs, thereby enabling a reduction in the amount of signaling.

[0670] For example, the relationship between the SRS transmission setting and the sounding BWP used for transmitting the SRS may be statically set in advance by a standard or the like. This eliminates the need for the gNB to notify the UE of this setting. Furthermore, the relationship between the SRS transmission setting and the sounding BWP used for transmitting the SRS may be set, for example, so that the sounding BWP and the SRS transmission band are the same. For example, this allows the UE to easily determine the setting of the sounding BWP to be switched to.

[0671] After transmitting the SRS, the UE may switch to an active BWP for communication other than the previous sounding. The UE switches to the active BWP after transmitting the SRS even without notification of switching to the active BWP from the gNB. This reduces the amount of signaling.

[0672] In FIG. 35, BWP#1 4905, BWP#2 4906, BWP#3 4907, and BWP#4 4908 are set as BWPs to be used for communications other than sounding.

[0673] In Figure 35, for example, the gNB configures sounding BWPs for the UE so that they cover the entire UL frequency band. 4901 is sounding BWP #1, 4902 is sounding BWP #2, 4903 is sounding BWP #3, and 4904 is sounding BWP #4. Sounding BWPs #1 to #4 are configured so that the entire UL frequency band is covered by sounding BWPs #1 to #4.

[0674] In addition, the gNB configures the UE for SRS transmission within the range of the sounding BWP for each sounding BWP. This allows the UE to recognize the SRS transmission configuration in the sounding BWP and transmit SRS.

[0675] The gNB selects the next sounding BWP to be used from the four sounding BWPs configured for the UE to perform the switching. The switching may be performed from a BWP for communications other than sounding to the sounding BWP, or between sounding BWPs. For example, the gNB configures BWP#1 as the active BWP for communications other than sounding for the UE.

[0676] Assume that switching from BWP#1 to sounding BWP#1 is required. The gNB transmits information for switching to the UE via PDCCH, including the information for switching in DCI. The UE receives the information for switching and uses the information to switch to sounding BWP#1. In sounding BWP#1, the UE transmits SRS using a preset SRS transmission setting.

[0677] For example, in order for the gNB to perform normal communication with the UE, the gNB switches from sounding BWP#1 to BWP#1, which is a BWP for communication other than sounding. Here, the BWP after switching does not have to be the original BWP#1. For example, the gNB may switch to BWP#2, BWP#3, or BWP#4. The gNB may notify the UE of the switching to a BWP for communication other than sounding by including information in DCI via PDCCH.

[0678] Alternatively, if the sounding BWP setting period is set by the standard or set for the UE by the gNB, the UE may return to the setting of BWP#1, which is a BWP for communications other than sounding. This makes it possible to reduce the information required to switch to a BWP for communications other than sounding.

[0679] One or more sounding BWP settings may be grouped together. Hereinafter, this group is referred to as a sounding BWP set. A sounding BWP set may be used to switch between sounding BWPs. Information indicating switching to a sounding BWP set may be provided as a setting for successively switching between sounding BWPs within a sounding BWP set. This information may be included in the information indicating switching to a sounding BWP. The order in which the sounding BWPs are switched within the sounding BWP set may also be included.

[0680] Alternatively, the switching order of the sounding BWP may be statically determined in advance by a standard, etc. For example, it may be determined that the switching order is in descending or ascending order of the sounding BWP identifier. This reduces the amount of information notified from the gNB to the UE. By continuously switching the sounding BWP in this way, it becomes possible to transmit SRS over the entire UL frequency band. Sounding becomes possible over the entire UL frequency band.

[0681] A method for transmitting SRS by BWP switching has been disclosed. Another method will be disclosed. Conventionally, one active BWP was set for a UE, but multiple active BWPs can be set. Multiple active DL-BWPs may also be set. Also, multiple active UL-BWPs may also be set. In this way, the UE can transmit SRS within the range of multiple active BWPs. This eliminates the need for BWP switching.

[0682] This paper discloses a scheduling method when multiple active BWPs are configured. In DL, scheduling is performed for each active DL-BWP. The same active DL-BWP is used to transmit DL signals or channels and their corresponding scheduling information. Scheduling for UL signal or channel transmission is performed using any active DL-BWP. The scheduling information may include an identifier of the active UL-BWP for which scheduling is performed. By receiving the identifier of the active UL-BWP, the UE can identify which active UL-BWP is being scheduled.

[0683] As another scheduling method, the transmission of the DL signal or channel and the transmission of the corresponding scheduling information may be performed using different active DL-BWPs. The scheduling information may include an identifier of the active DL-BWP for which scheduling is performed. By receiving the identifier of the active DL-BWP, the UE can identify which active DL-BWP is being scheduled.

[0684] The scheduling information is included in DCI and notified using PDCCH. When the gNB configures BWPs for the UE in advance, it may assign numbers to one or more BWPs to be configured. The numbers may be assigned within the DL-BWP. The numbers may be assigned within the UL-BWP. The numbers may be used as the identifier of the active UL-BWP included in the scheduling information or as the identifier of the active DL-BWP. Since the active BWP can be indicated with less information than when an identifier is used, it is possible to reduce the amount of information.

[0685] Scheduling may be performed using one of multiple active DL-BWPs. The gNB performs scheduling for the UE using one active DL-BWP. Hereinafter, this one active DL-BWP is referred to as the primary active DL-BWP. In this way, the UE does not need to receive scheduling information from all active DL-BWPs. This makes it possible to reduce the power consumption of the UE.

[0686] The multiple active BWPs are set from multiple pre-configured BWP configurations. The gNB selects multiple active BWPs from the multiple pre-configured BWP configurations and notifies the UE. The identifier of each BWP may be used as information indicating the selected multiple active BWPs.

[0687] For this notification, L1 / L2 signaling may be used, as in the conventional notification of active BWP. Information on multiple active BWPs may be included in DCI and notified using PDCCH. Alternatively, MAC signaling may be used as another method for notifying active BWP. This makes it possible to reduce the reception error rate at the UE, thereby reducing malfunctions.

[0688] When scheduling is performed in any active DL-BWP, the UE monitors the scheduling information of the active DL-BWP according to the information of the received active DL-BWP, so that the UE can receive in the active DL-BWP and transmit in the active UL-BWP.

[0689] In the method of performing scheduling using one active DL-BWP, the gNB may notify the UE of information about the active DL-BWP for which scheduling is performed. The UE monitors the scheduling information of the active DL-BWP for which scheduling is performed. The information about the active DL-BWP for which scheduling is performed may be notified to the UE together with the information about the active BWP. In this way, scheduling can be performed using one active DL-BWP.

[0690] The PRACH or PUCCH may be transmitted using one active UL-BWP. The gNB may notify the UE of the information about the active UL-BWP. The information may be notified to the UE together with the information about the active BWP. In this way, it is possible to transmit the PRACH or PUCCH using one active UL-BWP.

[0691] SRS transmission may be performed using multiple active UL-BWPs. The UE will be able to transmit SRS within the range of multiple active UL-BWPs. The gNB configures SRS for each active UL-BWP for the UE. Alternatively, SRS may be configured for the entire UL frequency band. When SRS is configured for the entire UL frequency band, it may be possible to transmit only SRS configuration within the range of the active UL-BWP. The SRS configuration may be the same as that disclosed in the second embodiment. The gNB notifies the UE of information regarding the SRS configuration.

[0692] A UE that receives SRS configuration information for each active UL-BWP from a gNB transmits SRS using the corresponding active UL-BWP using the SRS configuration information. In the case of aperiodic SRS transmission configuration, information for identifying the slot in which to transmit SRS may be notified by L1 / L2 signaling. The information may be a slot number or an offset value from the received slot. The offset value may be in slot units. The information may be notified by any active DL-BWP or by the primary active DL-BWP.

[0693] It is also possible to avoid transmitting SRS simultaneously over multiple active UL-BWPs. It is recommended to configure the SRS transmission timing to differ between active UL-BWPs. The UE does not transmit SRS simultaneously over multiple active UL-BWPs. For example, when configuring SRS for each active UL-BWP, the symbol used to transmit SRS may be different. Since the SRS transmission timing differs between active UL-BWPs, the UE does not transmit SRS simultaneously over multiple active UL-BWPs.

[0694] This allows transmission from the UE with low distortion and also reduces power consumption.

[0695] It is possible to transmit SRS using some of the active UL-BWPs and transmit other UL signals or UL channels using other active UL-BWPs. The UE does not transmit SRS and other UL signals or UL channels using the same active UL-BWP. This simplifies control and reduces the occurrence of malfunctions.

[0696] It is also possible to prevent simultaneous transmission of SRS and other UL channels or UL signals using multiple active UL-BWPs. The UE does not transmit SRS and other UL channels or UL signals using multiple active UL-BWPs. This allows transmission from the UE to be performed with low distortion. It also reduces power consumption.

[0697] If there is overlap in the frequency ranges of multiple active BWPs, a priority may be set for each active BWP. The priority may be statically determined in advance by a standard, etc. The gNB and UE can commonly recognize the priority. The priority may also be notified from the gNB to the UE. The priority may be notified to each UE individually or for each UE group. Alternatively, the priority may be notified for each cell. The priority may be notified using RRC signaling or MAC signaling. Alternatively, the priority may be notified using L1 / L2 signaling. In the case of notifying for each cell, the priority may be broadcast by being included in broadcast information.

[0698] This allows the UE to determine which active DL-BWP should have priority for monitoring its scheduling information, which is useful when, for example, resources to which scheduling information is mapped overlap between active DL-BWPs.

[0699] In the UL, the UE can recognize which active UL-BWP should be used to transmit UL signals or UL channels with priority, which is useful when the transmission timing and frequency of UL signals or UL channels overlap between active UL-BWPs.

[0700] According to the method disclosed in the third embodiment, it is possible to appropriately set the transmission of SRS in the UL frequency band. Since UL sounding is possible in a desired UL frequency band, it is possible to improve communication quality.

[0701] Embodiment 4 In a single UE, when two PUSCH transmissions with different latency requirements exist, the PUSCH transmissions may be allocated to the same time and / or frequency resources. For example, when a PUSCH transmission requiring normal latency (hereinafter sometimes referred to as a normal latency PUSCH) and a PUSCH transmission requiring low latency (hereinafter sometimes referred to as a low latency PUSCH) exist, if the low latency PUSCH transmission is allocated to some of the symbols allocated to the normal latency PUSCH transmission in a certain slot, the allocation of time and / or frequency resources may overlap.

[0702] The UE may prioritize transmission of a low-latency PUSCH in the slot. That is, the UE may not transmit a normal-latency PUSCH in the slot. Alternatively, the UE may transmit a normal-latency PUSCH only until low-latency PUSCH transmission begins. Alternatively, the UE may not transmit a normal-latency PUSCH in time and / or frequency resources that collide with low-latency PUSCH transmission. Alternatively, the UE may transmit a normal-latency PUSCH after the slot.

[0703] If the above-described operation is applied when the BWP used in the low-latency PUSCH (hereinafter sometimes referred to as the low-latency BWP) and the BWP used in the normal-latency PUSCH (hereinafter sometimes referred to as the normal-latency BWP) are different, the following problem occurs. For example, suppose that scheduling of a low-latency PUSCH occurs when normal-latency PUSCHs are scheduled consecutively for each slot. Suppose that a BWP switching notification is not included in the PDCCH scheduling the normal-latency PUSCH. Also, suppose that the period from the PDCCH scheduling the normal-latency PUSCH to the start of transmission of the PUSCH includes the PDCCH scheduling the low-latency PUSCH and the low-latency PUSCH. In the above, the BWP used by the UE is switched to the low-latency BWP when transmitting the low-latency PUSCH, and the PDCCH that schedules the normal-latency PUSCH does not include a BWP switching notification. Therefore, the UE cannot transmit the normal-latency PUSCH after transmitting the low-latency PUSCH. This may cause a decrease in the PUSCH transmission rate in the communication system. Furthermore, there may be a discrepancy between the base station and the UE regarding the BWP used by the UE, which may cause malfunction.

[0704] Figure 36 is a diagram illustrating a problem that occurs when different BWPs are used for a low-latency PUSCH and a normal-latency PUSCH. In Figure 36, BWP#1 indicates a normal-latency BWP, and BWP#2 indicates a low-latency BWP. The example shown in Figure 36 illustrates a case where BWP#1 and BWP#2 have different numerologies.

[0705] 36, the base station transmits PDCCHs 5101, 5102, and 5103 to the UE. PDCCHs 5101 and 5102 each include information about a PUSCH that is allocated two slots later and transmitted using BWP #1, but do not include a BWP switching instruction. PDCCH 5103 includes information about a PUSCH that is allocated two slots later in BWP #2, and also includes an instruction to switch the BWP to BWP #2. In FIG. 36, because the slot of BWP #2 that is allocated by PDCCH 5103 is allocated halfway through the slot of BWP #1 that is allocated by PDCCH 5101, the UE transmits PUSCH 5111 in BWP #1 until halfway through the slot, and then switches to BWP #2 and transmits PUSCH 5113. However, since PDCCH 5102 does not include a BWP switching instruction, the UE cannot transmit PUSCH 5112 in the slot next to BWP#1.

[0706] 36 shows the case where BWP #1 and BWP #2 have different numerologies, but the same problem occurs when the numerologies of both BWPs are the same. For example, the same problem occurs when the period from the PDCCH that schedules the low latency PUSCH to the start of transmission of the PUSCH is set shorter than the period from the PDCCH that schedules the normal latency PUSCH to the start of transmission of the PUSCH.

[0707] A solution to the aforementioned problem is disclosed.

[0708] The UE may not switch from a low-latency BWP to a normal-latency BWP. The UE may not transmit a scheduled normal-latency PUSCH. The UE may discard information about the scheduling of the PUSCH. The base station may schedule a normal-latency PUSCH again for the UE. The scheduling information may include information about BWP switching. The UE uses the information about BWP switching to switch the BWP in use to a normal-latency BWP, thereby enabling transmission of a normal-latency PUSCH.

[0709] Another solution is disclosed. The UE may switch from a low-latency BWP to a normal-latency BWP. The UE may transmit a scheduled normal-latency PUSCH. The BWP switching in the UE may be performed even when the scheduling information for the normal-latency PUSCH does not include a BWP switching instruction. This makes it possible to improve, for example, the transmission rate of the normal-latency PUSCH.

[0710] Another solution will be disclosed. The base station may notify the UE of information regarding BWP switching after PUSCH transmission. The information may be included in information regarding PUSCH scheduling. The information may be, for example, information indicating whether to restore the used BWP after PUSCH transmission. The UE may use the information to switch the used BWP after PUSCH transmission. For example, the UE may restore the used BWP to the original normal latency BWP after PUSCH transmission. This makes it possible to prevent inconsistencies in the used BWP between the base station and the UE when, for example, PUSCH scheduling with different latencies exists.

[0711] The above-described information regarding BWP switching after PUSCH transmission may also be applied to PDSCH scheduling, thereby achieving, for example, the same effects as those described above.

[0712] Other solutions will be disclosed. The base station may notify the UE of only PUSCH scheduling information including a BWP switching instruction. A DCI including a BWP switching instruction, for example, DCI format 0_0 (see Non-Patent Document 25 (3GPP TS38.212 v15.0.0)) may not be used in an uplink grant from the base station to the UE. In the above description, the BWP information included in the BWP switching instruction may be the same as or different from the BWP currently used by the UE. The above operation may be applied, for example, when multiple BWPs are configured for the UE. The UE may not expect to receive a DCI that does not include a BWP switching instruction. The UE may only receive PUSCH scheduling information that includes a BWP switching instruction. The UE may perform irregular processing when receiving a DCI that does not include a BWP switching instruction. The UE may discard PUSCH scheduling information that does not include a BWP switching instruction. As another example, the UE may notify the base station of the occurrence of an irregularity. The notification may include information indicating that a DCI not including a BWP switching instruction has been received, which can prevent inconsistencies in the BWP used between the base station and the UE, for example, when PUSCH scheduling with different latencies exists.

[0713] In this fourth embodiment, the numerology of the low latency BWP and the normal latency BWP may be the same or different. For example, even if the numerology of both BWPs is the same, by applying the method shown in this fourth embodiment, it is possible to prevent discrepancies in the BWPs used between the base station and the UE.

[0714] According to the fourth embodiment, it becomes possible to prevent discrepancies between the base station and the UE regarding the BWP used by the UE, and as a result, it becomes possible to prevent malfunctions in the communication system.

[0715] Embodiment 5. In PUSCH transmission, the slot interval from when the UE receives the PDCCH including the uplink grant until when it transmits the PUSCH is given in units of the slot length of the PUSCH (see Non-Patent Document 15 (TS 38.214 v15.0.0)).

[0716] In the above, the following problem occurs. That is, when the downlink and uplink numerologies are different, especially when the downlink slot length is longer than the uplink slot length, the slot interval from PDCCH reception to PUSCH transmission varies depending on the position of the uplink slot. As a result, the delay of PUSCH transmission varies depending on the slot position.

[0717] 37 is a diagram illustrating a problem in PUSCH scheduling when the downlink and uplink have different numerologies. In FIG. 37, all scheduling information related to PUSCHs 5202 to 5205 is transmitted by PDCCH 5201. In this case, the slot intervals from PDCCH 5201 to PUSCHs 5202 to 5205 are 2 to 5 slots, respectively, and variations occur depending on the slot positions. As a result, variations occur in the delay of PUSCH transmission depending on the slot positions.

[0718] A solution to the aforementioned problem is disclosed.

[0719] The base station may include the PUSCH scheduling information in a PDCCH located in the middle of a slot and notify the UE. The UE may obtain the PUSCH scheduling information by receiving the PDCCH located in the middle of a slot. The PDCCH may be, for example, a PDCCH for non-slot scheduling.

[0720] The position of the uplink slot may determine whether the uplink scheduling information is included in the PDCCH at the beginning of the downlink slot or in the PDCCH in the middle of the slot. Also, the position of the uplink slot may determine the position of the slot in which the PDCCH including the uplink scheduling information is arranged. This makes it possible to reduce, for example, the variation in PUSCH transmission delay.

[0721] Figure 38 is a diagram showing PUSCH scheduling using a PDCCH located in the middle of a slot. Figure 38 shows an example in which the uplink slot length is shorter than the downlink slot length. Figure 38 also shows an example in which both the PDCCH at the beginning of a slot and the PDCCH located in the middle of a slot are used. In Figure 38, signals that are common to Figure 37 are assigned the same reference numerals, and common explanations will be omitted.

[0722] 38, scheduling information for PUSCHs 5202 and 5203 is included in PDCCH 5201 at the beginning of the slot and reported to the UE. Scheduling information for PUSCHs 5204 and 5205 is included in PDCCH 5301 in the middle of the slot and reported to the UE.

[0723] The correspondence relationship between the positions of the PDCCH and the positions of the PUSCH may be determined by a standard, or the base station may determine the correspondence relationship and notify or broadcast it to the UE.

[0724] The symbol number including the PDCCH may be included in the condition and / or formula (see Non-Patent Document 15 (TS 38.214 v15.0.0)) that determines the slot interval from when the UE receives a PDCCH including an uplink grant until when it transmits a PUSCH. The symbol number may be the first symbol of the PDCCH or the last symbol number. As another example, information that identifies a non-slot, such as a non-slot number, may be included in the condition and / or formula. The non-slot number may be, for example, a number assigned by dividing a slot into units of several symbols, or may be a number assigned to each position within a slot to which a non-slot is assigned. This makes it possible to use common parameters, for example, when using a PDCCH located in the middle of a slot and when using a PDCCH located at the beginning of a slot. As a result, the number of parameter options that a base station can select in scheduling increases, enabling improved flexibility in uplink transmission.

[0725] As another example, the conditions and / or formulas for determining the slot interval may be given in symbol units or in non-slot number units, which may allow for the setting of a time interval value shorter than the slot unit, thereby reducing communication latency.

[0726] The method disclosed in the fifth embodiment may be applied to other uplink signals or channels. For example, the method may be applied to SRS, PUCCH including HARQ feedback, or PUSCH including CSI report. This makes it possible to reduce the variation in delay depending on the position of the uplink slot even in the above-mentioned signals or channels.

[0727] The method disclosed in the fourth embodiment may be applied to the fifth embodiment. For example, in the fourth embodiment, a low-latency PUSCH transmitted using a low-latency BWP may be scheduled using a PDCCH in the middle of a slot. This makes it possible to prevent a discrepancy in the BWP used between the base station and the UE when, for example, a PUSCH with normal latency and a PUSCH requiring even lower latency are transmitted in parallel.

[0728] According to the fifth embodiment, it is possible to reduce the variation in delay of the uplink PUSCH depending on the slot position, and as a result, it is possible to reduce the delay in transmitting the uplink PUSCH.

[0729] The above-described embodiments and their modifications are merely examples of the present invention, and the embodiments and their modifications can be freely combined within the scope of the present invention. Furthermore, any component of the embodiments and their modifications can be modified or omitted as appropriate.

[0730] For example, in the above-described embodiments and their modifications, a subframe is an example of a time unit for communication in a fifth-generation base station communication system. It may also be a scheduling unit. In the above-described embodiments and their modifications, the processing described as being performed in subframe units may also be performed in TTI units, slot units, subslot units, or minislot units.

[0731] Although the present invention has been described in detail, the above description is illustrative in all respects and does not limit the present invention, and it is understood that countless variations not illustrated can be assumed without departing from the scope of the present invention. [Explanation of symbols]

[0732] 200 communication system, 202 communication terminal device, 203 base station device.

Claims

1. a plurality of user equipments (UEs) each transmitting a sounding reference signal (SRS); A user equipment in a communication system including a base station that wirelessly communicates with a plurality of the user equipments, receiving, from the base station, configuration information regarding radio resources of the sounding reference signals allocated to other user equipments using a Radio Resource Control (RRC) reconfiguration message; The configuration information includes information indicating that a type of the sounding reference signal corresponding to the radio resource allocated to the other user equipment is a periodic SRS, and information regarding a transmission period and an offset regarding the periodic SRS. User equipment.

2. Receive the configuration information when in the RRC_Connected state The user device of claim 1 .

3. The configuration information includes information identifying the radio resource, information about a port corresponding to the radio resource, information about a comb configuration of the radio resource, information about a transmission symbol of the radio resource, information about a transmission frequency of the radio resource, information about a sequence of the radio resource, information about a beam for the radio resource, and information about a numerology of the radio resource.

3. A user device according to claim 1 or 2.

4. The user device receiving information from the base station regarding the suspension of a physical uplink shared channel (PUSCH) transmission; Stopping the physical uplink shared channel (PUSCH) transmission based on information about the stop. The user device of claim 1 .

5. a plurality of user equipments (UEs) each transmitting a sounding reference signal (SRS); a base station in a communication system that wirelessly communicates with a plurality of user devices, Notifying one user equipment of configuration information regarding radio resources of the sounding reference signals allocated to another user equipment by using an RRC (Radio Resource Control) reconfiguration message; The configuration information includes information indicating that a type of the sounding reference signal corresponding to the radio resource allocated to the other user equipment is a periodic SRS, and information regarding a transmission period and an offset regarding the periodic SRS. Base station.

6. a plurality of user equipments (UEs) each transmitting a sounding reference signal (SRS); a base station that wirelessly communicates with a plurality of the user devices, The base station notifies one user equipment of configuration information regarding radio resources of the sounding reference signals allocated to other user equipments by using an RRC (Radio Resource Control) reconfiguration message; The configuration information includes information indicating that a type of the sounding reference signal corresponding to the radio resource allocated to the other user equipment is a periodic SRS, and information regarding a transmission period and an offset regarding the periodic SRS. Communication system.

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