Base station, terminal equipment, and communication method

Abstract

This invention provides a mechanism that enables more efficient communication in a communication system where base stations and terminal devices communicate. [Solution] The base station of this disclosure applies a first resource mapping to a plurality of signals to map the plurality of such signals to a time resource or a logic resource. The base station applies a Fourier transform to the plurality of signals to which the first resource mapping has been applied to generate a first transformed signal. The base station applies a second resource mapping to the first transformed signal to map the first transformed signal to a frequency resource and a time resource. The base station applies an inverse Fourier transform to the first transformed signal to which the second resource mapping has been applied to generate a second transformed signal. The base station generates a downlink signal to which a single-carrier modulation scheme has been applied from the second transformed signal.

Description

Technical Field

[0001] The present disclosure relates to a base station, a terminal device, and a communication method.

Background Art

[0002] Wireless access methods and wireless networks of cellular mobile communications (hereinafter, also referred to as "Long Term Evolution (LTE)", "LTE-Advanced (LTE-A)", "LTE-Advanced Pro (LTE-A Pro)", "New Radio (NR)", "New Radio Access Technology (NRAT)", "Evolved Universal Terrestrial Radio Access (EUTRA)", or "Further EUTRA (FEUTRA)") are being studied in the Third Generation Partnership Project (3rd Generation Partnership Project: 3GPP (registered trademark)).

[0003] In the following description, LTE includes LTE-A, LTE-A Pro, and EUTRA, and NR includes NRAT and FEUTRA. In LTE, the base station (base station device) is an eNodeB (evolved NodeB), in NR, the base station (base station device) is a gNodeB, and in LTE and NR, the terminal device (mobile station, mobile station device, terminal) is also referred to as a UE (User Equipment). LTE and NR are cellular communication systems in which a plurality of areas covered by a base station are arranged in a cell shape. A single base station may manage a plurality of cells.

[0004] 5G NR is a Radio Access Technology (RAT) distinct from LTE, serving as the next-generation wireless access method. NR is an access technology capable of supporting various use cases, including Enhanced Mobile Broadband (eMBB), Massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). Standardization efforts have been underway to support a technical framework that addresses the usage scenarios, requirements, and deployment scenarios in these use cases.

[0005] In recent years, support for high-frequency bands such as millimeter waves and terawaves, as well as cost reduction of base stations, have been progressing. Consequently, there is a need to reduce the Peak-To-Average-Power Ratio (PAPR) in downlink communications. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special Publication No. 2022-551796 [Non-patent literature]

[0007] [Non-Patent Document 1] R1-1706156, “NR PSS and SSS Design”, Intel Corporation, RAN1 #88bis, 7th April 2017. [Overview of the project] [Problems that the invention aims to solve]

[0008] To address the PAPR issues, such as the reduction of base station costs mentioned above, it is necessary to consider means of implementing communications more efficiently.

[0009] Therefore, this disclosure provides a mechanism that enables more efficient communication in a communication system in which a base station and terminal equipment communicate.

[0010] It should be noted that the above-mentioned problems or objectives are merely one of several problems or objectives that can be solved or achieved by the multiple embodiments disclosed herein. [Means for solving the problem]

[0011] The base station of this disclosure applies a first resource mapping to a plurality of signals to map the plurality of such signals to a time resource or a logic resource. The base station applies a Fourier transform to the plurality of signals to which the first resource mapping has been applied to generate a first transformed signal. The base station applies a second resource mapping to the first transformed signal to map the first transformed signal to a frequency resource and a time resource. The base station applies an inverse Fourier transform to the first transformed signal to which the second resource mapping has been applied to generate a second transformed signal. The base station generates a downlink signal to which a single-carrier modulation scheme has been applied from the second transformed signal. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows an example of signal processing for 5G NR uplink communication. [Figure 2] This diagram shows an example of a wireless network provided by a communication system. [Figure 3] This diagram shows an overview of the satellite communications provided by the communication system. [Figure 4] This figure shows an example of a cell composed of a non-geostationary satellite. [Figure 5] This figure shows an example of resource allocation for PDCCH. [Figure 6] This figure shows an example of resource allocation for PBCH. [Figure 7] This figure shows an example of the resource allocation of DMRS included in PDCCH. [Figure 8] FIG. is a diagram showing an example of resource allocation of DMRS included in PBCH. [Figure 9] FIG. is a diagram showing an example of communication processing according to the proposed technology of the present disclosure. [Figure 10] FIG. is a diagram for explaining an overall configuration example of a communication system according to an embodiment of the present disclosure. [Figure 11] FIG. is a block diagram showing a configuration example of a base station according to an embodiment of the present disclosure. [Figure 12] FIG. is a block diagram showing a configuration example of a wireless transmission unit according to an embodiment of the present disclosure. [Figure 13] FIG. is a block diagram showing a configuration example of a first signal waveform transmission unit according to an embodiment of the present disclosure. [Figure 14] FIG. is a block diagram showing a configuration example of a second signal waveform transmission unit according to an embodiment of the present disclosure. [Figure 15] FIG. is a block diagram showing a configuration example of a terminal device according to an embodiment of the present disclosure. [Figure 16] FIG. is a block diagram showing a configuration example of a wireless reception unit according to an embodiment of the present disclosure. [Figure 17] FIG. is a block diagram showing a configuration example of a first signal waveform reception unit according to an embodiment of the present disclosure. [Figure 18] FIG. is a block diagram showing a configuration example of a second signal waveform reception unit according to an embodiment of the present disclosure. [Figure 19] FIG. is a sequence diagram showing the flow of communication processing of downlink communication according to an embodiment of the present disclosure. [Figure 20] FIG. is a diagram showing an example of signal processing of downlink communication according to an embodiment of the present disclosure. [Figure 21] FIG. is a diagram showing an example of multiplexing of synchronization signals according to an embodiment of the present disclosure. [Figure 22] FIG. is a diagram showing an example of multiplexing of synchronization signals and system information according to an embodiment of the present disclosure. [Figure 23] FIG. is a diagram showing an example of multiplexing of system information and reference signals according to an embodiment of the present disclosure. [Figure 24]This figure shows an example of multiplexing of synchronization signals, system information, and reference signals according to the embodiments of this disclosure. [Figure 25] This figure shows another example of multiplexing of synchronization signals and system information according to the embodiments of this disclosure. [Figure 26] This figure shows another example of multiplexing of synchronization signals and system information according to the embodiments of this disclosure. [Figure 27] This figure shows an example of multiplexing of control signals and reference signals according to the embodiments of this disclosure. [Figure 28] This figure shows an example of CCE-to-REG mapping with interleaving applied. [Figure 29] This figure shows an example of CCE-to-REG mapping without interleaving. [Figure 30] This figure shows an example of multiplexing of data signals and reference signals according to the embodiments of this disclosure. [Figure 31] This figure shows another example of multiplexing of data signals and reference signals according to the embodiments of this disclosure. [Figure 32] This figure shows an example of multiplexing of a reference signal according to an embodiment of this disclosure. [Figure 33] This figure shows an example of a resource set according to an embodiment of this disclosure. [Figure 34] This figure shows an example of the receiving process of a downlink signal according to an embodiment of the present disclosure. [Figure 35] This figure shows an example of the receiving process of a downlink signal according to an embodiment of the present disclosure. [Figure 36] This figure shows another example of the downlink signal reception processing according to the embodiments of this disclosure. [Figure 37] This figure shows another example of the downlink signal reception processing according to the embodiments of this disclosure. [Figure 38] This figure shows another example of the downlink signal reception processing according to the embodiments of this disclosure. [Modes for carrying out the invention]

[0013] Embodiments of this disclosure will be described in detail below with reference to the attached drawings. In this specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant explanations will be omitted.

[0014] Furthermore, in this specification and drawings, similar components of embodiments may be distinguished by adding at least one different alphabet and number after the same reference numeral. However, if there is no need to particularly distinguish each of the similar components, only the same reference numeral will be used.

[0015] The one or more embodiments (including examples, modifications, and applications) described below can each be implemented independently. On the other hand, at least some of the embodiments described below may be implemented in appropriate combination with at least some of the other embodiments. These embodiments may contain novel features that differ from each other. Therefore, these embodiments may contribute to solving different objectives or problems and may produce different effects.

[0016] <<1. Introduction>> <1-1. Background> <1-1-1. DFT-S-OFDM Transmission> First, 5G NR uplink communication uses OFDM (Orthogonal Frequency Division Multiplexing) transmission and DFT-S-OFDM (Discrete Fourier Transform Spread OFDM) transmission.

[0017] Figure 1 shows an example of signal processing for 5G NR uplink communication.

[0018] As shown in Figure 1, error correction parity bits are added to the transmitted signal sequence using error correction coding (Channel coding). Subsequently, rate matching extracts a number of bits from the transmitted signal sequence according to the transmission resources and modulation scheme. Interleaving and scrambling are then applied to the extracted bits.

[0019] Next, the bit sequence is mapped to complex signal points through a modulation process. If transmission is performed across multiple layers, the bit sequence is mapped to complex signal points in each layer.

[0020] In DFT-S-OFDM transmission, a Discrete Fourier Transformation (DFT) process called Transform precoding is performed, as shown in Figure 1. Note that this process, i.e., the DFT process performed here, may be called by a name other than Transform precoding. Furthermore, in OFDM transmission, this Transform precoding process is omitted.

[0021] Subsequently, transmission weights are applied via pre-coding, resource mapping is performed, and then OFDM processing converts the frequency-domain transmission signal into a time-domain transmission signal (time-axis signal) for transmission. Since the process in Figure 1 is uplink communication, the time-domain transmission signal is sent from the terminal device to the base station.

[0022] On the receiving end, the time-domain received signal is first converted into a frequency-domain signal (frequency-axis signal) by OFDM processing. After resource demapping, frequency equalization is performed to compensate for distortion caused by radio wave propagation.

[0023] In DFT-S-OFDM transmission, as shown in Figure 1, an IDFT (Inverse Discrete Fourier Transformation) process called Transform de-precoding is performed. In OFDM transmission, this Transform de-precoding process is omitted.

[0024] Subsequently, the signal mapped to multiple layers is returned, and soft determination is performed on each bit from the complex signal points. De-scrambling, de-interleave, de-rate matching, and error correction decoding (channel decoding) are performed on the bit values ​​obtained by this soft determination to obtain the received signal sequence.

[0025] Thus, conventionally, in uplink communication, a single-carrier system (DFT-S-OFDM transmission in the example above) has been introduced with the aim of reducing PAPR.

[0026] As mentioned above, in recent years, with the support of high-frequency bands such as millimeter waves and terawaves, and the reduction of base station costs, there has been a growing demand to reduce PAPR in downlink communications as well.

[0027] When considering cost reductions and coverage expansion for such base stations, it is conceivable to introduce a single-carrier system with a low PAPR (Percentage-Assisted Performance Rate) to downlink communications as well.

[0028] <1-1-2. Satellite Communications> Satellite communications are one type of communication where PAPR reduction is required. Small satellites, also known as Cube-sat or micro-satellite, are examples of mobile satellites used in satellite communications. Small satellites are inferior to conventional satellites in terms of power and antenna gain. Thus, a challenge for small satellites is the PAPR problem resulting from the lack of high-performance power amplifiers.

[0029] Therefore, the introduction of a single-carrier system with a low PAPR (Periodic Action Rate) is being considered for satellite communications.

[0030] Here, we will explain the basics of satellite communications. For example, in cellular mobile communications, base stations (e.g., eNodeB (eNB), gNodeB (gNB), RAN nodes (including EUTRAN and NGRAN)) or relay devices installed on the ground constitute cells (e.g., macrocells, microcells, femtocells, or small cells) and provide a wireless network. Base stations or relay devices installed on the ground are also called ground stations.

[0031] The wireless network provided by this ground station is called a terrestrial network.

[0032] On the other hand, due to increasing demands for reducing base station costs and providing coverage to areas where radio waves from base stations are difficult to reach, there is a growing need to provide wireless networks to terminal devices via base stations / relay stations other than ground stations, such as satellite stations and aircraft stations. These base stations / relay stations other than ground stations are called non-ground stations (or non-ground base stations / non-ground relay stations).

[0033] Furthermore, wireless networks provided from non-terrestrial stations are referred to as non-terrestrial networks (NTN).

[0034] Other communication devices besides ground stations include satellite stations and aeronautical stations. Satellite stations are devices equipped with radio communication capabilities that float outside the atmosphere, such as artificial satellites. Satellite stations here include low Earth orbit (LEO) satellites, medium Earth orbit (MEO) satellites, geostationary Earth orbit (GEO) satellites, and highly elliptical orbit (HEO) satellites.

[0035] An aeronautical station is a device equipped with radio communication capabilities that floats within the atmosphere, such as an aircraft or balloon. Here, aeronautical stations include unmanned aircraft systems (UAS), tethered UAS, lighter than air UAS (LTA), heavier than air UAS (HTA), and high-altitude UAS platforms (HAPs).

[0036] Furthermore, communication equipment other than ground stations may also be referred to as base stations (e.g., eNodeB (eNB), gNodeB (gNB), RAN node (including EUTRAN and NGRAN)) from the perspective of cellular mobile communications compliant with 3GPP (registered trademark).

[0037] Figure 2 is a diagram illustrating an overview of a wireless network, including a non-terrestrial network. Figure 2 shows an example of a wireless network provided by the communication system SYS1. The communication system SYS1 in Figure 2 comprises a management device 101, ground stations 201-205, non-terrestrial stations 301-305, relay stations 401 and 402, and terminal devices 501 and 502.

[0038] The communication system SYS1 provides users with a wireless network capable of mobile communication through the coordinated operation of each wireless communication device that constitutes the communication system SYS1. The wireless network in this embodiment is composed of, for example, a wireless access network and a core network. Here, wireless communication devices refer to devices that have wireless communication functions, and in the example in Figure 2, these include the ground station 20, non-ground station 30, relay station 40, and terminal device 50.

[0039] The management device 10 is, for example, a device that constitutes the core network CN. The management device 10 is connected to the network PN. The management device 10 is connected to the ground station 20 and the non-ground station 30, enabling the terminal device 50 to connect to the network PN. The network PN is a public data network such as the Internet. The network PN is not limited to the Internet, and may be, for example, a LAN (Local Area Network), a WAN (Wide Area Network), a telephone network (mobile phone network, fixed telephone network, etc.), or a regional IP (Internet Protocol) network. Of course, the network PN may also be other mobile networks. For example, the network PN may be a cellular network provided by an entity different from the entity operating the communication system SYS1 (for example, an entity such as an MNO (Mobile Network Operator)).

[0040] The ground station 20 and the non-ground station 30 are base stations or relay stations. In the following description, the ground station 20 and the non-ground station 30 are assumed to be base stations, but they may also be relay stations. The ground station 20 is, for example, a ground base station installed on a structure on the ground, and the non-ground station 30 is, for example, a non-ground base station such as a satellite station or a HAPS (High Altitude Platform Station). The ground station 20 and the non-ground station 30 each constitute a cell. A cell is an area covered by wireless communication. A cell may be a macrocell, microcell, femtocell, or small cell. The communication system SYS1 may be configured to manage multiple cells with a single base station (satellite station), or it may be configured to manage one cell with multiple base stations.

[0041] In the example shown in Figure 2, ground stations 201 and 202 constitute terrestrial network TN1, and ground stations 203, 204, and 205 constitute terrestrial network TN2. Terrestrial network TN1 and terrestrial network TN2 are networks operated by, for example, a wireless communication carrier such as a telephone company.

[0042] Terrestrial networks TN1 and TN2 may be operated by different wireless communication carriers or by the same wireless communication carrier. Terrestrial networks TN1 and TN2 may also be considered as a single terrestrial network.

[0043] Terrestrial networks TN1 and TN2 are each connected to the core network. In the example in Figure 2, the ground station 20 that constitutes terrestrial network TN2 is connected to the core network CN1, which is configured by, for example, a management device 101.

[0044] If the wireless access method for the terrestrial network TN2 is LTE, then the core network CN1 is EPC. If the wireless access method for the terrestrial network TN2 is NR, then the core network CN1 is 5GC. Of course, the core network CN1 is not limited to EPC or 5GC; it could be a core network using other wireless access methods.

[0045] In the example shown in Figure 2, the terrestrial network TN1 is not connected to the core network, but the terrestrial network TN1 may be connected to the core network CN1. Furthermore, the terrestrial network TN1 may be connected to a different core network (not shown) than the core network CN1.

[0046] The core network CN1 includes, for example, a gateway device and a gateway switch, and is connected to network PN1 via the gateway device or gateway switch. As described above, network PN1 is a public network such as the Internet.

[0047] The gateway device may be a server device connected to the internet or a regional IP network. The gateway exchange is, for example, a switch connected to a telephone company's telephone network. The management device 101 may also function as a gateway device or a gateway exchange.

[0048] The non-terrestrial stations 30 shown in Figure 2 are, for example, satellite stations and aircraft stations. A group of satellite stations (or satellite stations) that constitute a non-terrestrial network is called a Space-borne Platform. Similarly, a group of aircraft stations (or aircraft stations) that constitute a non-terrestrial network is called an Airborne Platform.

[0049] In the example shown in Figure 2, non-ground stations 301, 302, and 303 constitute the spacebone platform SBP1, and non-ground station 304 constitutes the spacebone platform SBP2. In addition, non-ground station 305 constitutes the airbone platform ABP1.

[0050] The non-terrestrial station 30 may be able to communicate with the terrestrial network or core network via the relay station 40. Of course, the non-terrestrial station 30 may also be able to communicate directly with the terrestrial network or core network without going through the relay station 40.

[0051] Furthermore, the non-terrestrial station 30 may communicate with the terminal device 50 via the relay station 40, or it may communicate directly with the terminal device 50. In addition, the non-terrestrial stations 30 may communicate directly with each other without going through the relay station 40.

[0052] Relay station 40 relays communication between the ground equipment and the non-ground station 30. Relay stations are also called earth stations (Very Small Aperture Terminal, Gateway, Control Earth Station, HUB Station). Relay station 40 may be a ground station or a non-ground station. In the example in Figure 2, relay station 402 relays communication between ground station 20 and non-ground station 30, and relay station 401 relays communication between management equipment 10 and non-ground station 30.

[0053] Furthermore, the relay station 40 may relay communication between the terminal device 50 and the non-terrestrial station 30. Also, the relay station 40 may be able to communicate with other relay stations 40.

[0054] Terminal device 50 can communicate with both ground stations and non-ground stations. In the example shown in Figure 2, terminal device 501 can communicate with ground stations that constitute the terrestrial network TN1. Terminal device 501 can also communicate with non-ground stations that constitute the spacebone platforms SBP1 and SBP2.

[0055] Furthermore, terminal device 50 can communicate with non-terrestrial stations that constitute the airborne platform ABP1. Terminal device 50 may also communicate with relay station 40. Additionally, terminal device 50 may communicate directly with other terminal devices 50. Terminal device 501 may communicate directly with terminal device 502.

[0056] Examples of terminal devices 50 (earth terminal devices) compatible with non-terrestrial networks include mobile phones and smartphones, automobiles, buses, trains, aircraft, M2M (Machine to Machine) / IoT (Internet of Things) devices, and relay stations that relay satellite communications and base stations that receive satellite communications.

[0057] Each component of the Spacebone Platforms SBP1 and SBP2 communicates with the terminal device 50 via satellite. Satellite communication refers to wireless communication between a satellite station and a communication device.

[0058] Figure 3 shows an overview of satellite communications provided by the SYS1 communication system. Satellite stations are mainly divided into geostationary satellite stations and low Earth orbit satellite stations.

[0059] A geostationary satellite station is a satellite station located in geostationary orbit that revolves around the Earth at the same speed as the Earth's rotation. In the example shown in Figure 3, non-ground station 304, which is part of the Spacebone Platform SBP2, is a geostationary satellite station. Geostationary orbit is a satellite orbit at an altitude of approximately 35,786 km.

[0060] A geostationary orbit is also called a geostationary Earth orbit (GEO). The geostationary satellite station has a relative velocity of approximately 0 with respect to the ground-based terminal equipment 50, and is observed as stationary from the ground-based terminal equipment 50. The non-ground station 304 communicates with terminal equipment 501, 503, 504, etc., located on Earth.

[0061] Low Earth orbit (LEO) satellite stations are satellite stations that orbit in low Earth orbit. In the example in Figure 3, non-ground stations 301 and 302, which make up the Space Bone Platform SBP1, are low Earth orbit satellite stations. Low Earth orbit is a satellite orbit at an altitude of approximately 2000 km or less. Low Earth orbit is also called Low Earth Orbit (LEO).

[0062] Unlike geostationary satellite stations, low Earth orbit satellite stations have a relative velocity with respect to the ground-based terminal equipment 50, and are observed as moving from the perspective of the ground-based terminal equipment 50. Non-ground stations 301 and 302 each constitute a cell and communicate with terminal equipment 501, 503, 504, etc., located on Earth.

[0063] Note that Figure 3 only shows two non-ground stations, 301 and 302, as satellite stations constituting the Spacebone Platform SBP1. However, in reality, a satellite constellation is formed by many satellite stations. In this case, the number of satellite stations constituting the Spacebone Platform SBP1 is three or more (for example, tens to thousands).

[0064] Note that in the example in Figure 3, only geostationary and low Earth orbit satellite stations are shown as satellite stations, but the satellite stations constituting the SYS1 communication system may also include medium Earth orbit satellite stations. A medium Earth orbit satellite station is a satellite station that orbits in medium Earth orbit. Medium Earth orbit is an orbit located between low Earth orbit and geostationary orbit. Medium Earth orbit is also called a medium Earth orbit (MEO).

[0065] In addition, the satellite stations constituting the SYS1 communication system may include highly elliptical orbit (HEO) satellite stations. Furthermore, the satellite stations forming a satellite constellation may include not only low Earth orbit (Earth orbit) satellite stations, but also medium Earth orbit (MTR) satellite stations, highly elliptical orbit (HEO) satellite stations, and geostationary satellite stations.

[0066] Figure 4 shows an example of a cell formed by a non-geostationary satellite. Figure 4 shows cell C formed by a non-ground station 302. In the example in Figure 4, the non-ground station 302 is a low Earth orbit satellite station. Satellite stations orbiting in low Earth orbit communicate with ground terminal equipment 50 with a predetermined directivity toward the ground.

[0067] For example, in the example shown in Figure 4, the angle R is 40 degrees. In the example in Figure 4, the radius D of the cell C formed by the non-ground station 302 is, for example, 1000 km. The low Earth orbit satellite station moves at a constant speed. If it becomes difficult for the low Earth orbit satellite station to provide satellite communications to the ground terminal equipment 50, a subsequent low Earth orbit satellite station (neighbor satellite station) will provide satellite communications.

[0068] In the example shown in Figure 4, if the non-terrestrial station 302 becomes unable to provide satellite communication to the terrestrial terminal device 50, the subsequent non-terrestrial station 303 will provide satellite communication. Note that the values ​​of angle R and radius D mentioned above are merely examples and are not limited to those shown.

[0069] Medium Earth orbit (MED) and low Earth orbit (LE) satellites move through their orbits at very high speeds. For example, a LE satellite at an altitude of 600 km moves through its orbit at a speed of 7.6 km / s.

[0070] Low Earth orbit satellites form cells (or beams) on the ground with a radius of several tens to several hundreds of kilometers. As the satellite moves, the cells formed on the ground also move, so even if the ground terminal equipment does not move, a handover may be necessary. For example, if we assume a case where the diameter of the cell formed on the ground is 50 km and the ground terminal equipment does not move, a handover will occur in approximately 6 to 7 seconds.

[0071] As described above, the terminal device 50 is capable of wireless communication using a non-terrestrial network. Furthermore, the non-terrestrial station 30 of the communication system SYS1 constitutes a non-terrestrial network. This allows the communication system SYS1 to extend its services to terminal devices 50 located in areas not covered by the terrestrial network.

[0072] For example, the communication system SYS1 can provide services to terminal devices 50 in areas not covered by the terrestrial network (e.g., outside the coverage of cells provided by the ground station 20). The communication system SYS1 can provide public safety communications and critical communications to communication devices such as IoT (Internet of Things) devices and MTC (Machine Type Communications) devices.

[0073] Furthermore, using a non-terrestrial network improves service reliability and recoverability. This allows the SYS1 communication system to reduce its vulnerability to physical attacks or natural disasters.

[0074] Furthermore, the SYS1 communication system can provide service connections to aircraft terminal devices such as airplane passengers and drones, as well as to mobile terminal devices such as ships and trains. In addition, the SYS1 communication system can provide highly efficient multicast services such as A / V content, group communication, IoT broadcast services, software download services, and emergency messages, as well as highly efficient broadcast services. Moreover, the SYS1 communication system can also perform traffic offloading between terrestrial and non-terrestrial networks.

[0075] It should be noted that, while satellite communication is given here as an example of wireless communication that employs a single-carrier system for downlink communication, wireless communication employing a single-carrier system is not limited to satellite communication. In other words, the technology according to this embodiment is not limited to application to non-terrestrial networks, but can also be applied to terrestrial networks.

[0076] In the following explanation, for the sake of simplicity, the technology according to this embodiment will be described using downlink communication of a terrestrial network as an example, but the technology according to this embodiment can also be applied to downlink communication of a non-terrestrial network.

[0077] <1-2. Challenges> As mentioned above, in recent years, the support for high-frequency bands such as millimeter waves and terawaves, and the reduction of base station costs, have led to a demand for reducing PAPR (or Cubic Metric (CM)) in downlink communications.

[0078] Furthermore, small satellites (which could also be called Cube-sat or micro-satellite) being considered as a type of mobile satellite are inferior to conventional satellites in terms of power and antenna gain. Therefore, PAPR (Power Output Resonance) becomes a problem for small satellites due to their lack of high-performance power amplifiers.

[0079] To reduce PAPR (Periodic Action Restriction), the introduction of a single-carrier scheme (e.g., DFT-S-OFDM) for downlink communication is being considered.

[0080] When introducing a single-carrier system for downlink communication, it is necessary to continuously allocate the desired signals in the frequency domain in order to suppress the increase in PAPR.

[0081] However, in 5G NR and similar technologies, control signals (for example, PDCCH (Physical Downlink Control Channel) and PBCH (Physical Broadcast Channel)) and some of the reference signals included in the control signals (such as the De-Modulation Reference Signal (DMRS) included in PDCCH and PBCH) may be transmitted with resources allocated discontinuously in the frequency domain. Therefore, there is a problem that transmitting these signals may increase PAPR (Periodic Action Restriction).

[0082] Figure 5 shows an example of resource allocation for PDCCH. As shown in Figure 5, in 5G NR and the like, PDCCH is allocated to each UE in terms of frequency-time resources. Note that although Figure 5 shows PDCCHs destined for the 1st to 3rd UEs, the number of UEs to which PDCCHs are destined can be two or fewer, or four or more.

[0083] Figure 6 shows an example of resource allocation in a PBCH. As shown in Figure 6, in 5G NR and similar systems, frequency-time resources are allocated discontinuously in terms of frequency. In addition, the PSS (Primary Synchronization Signal) and SSS (Secondary Synchronization Signal) are also allocated discontinuously in terms of time.

[0084] Thus, signals that are arranged discontinuously are not limited to control signals or reference signals. For example, synchronization signals may also be arranged discontinuously.

[0085] Figure 7 shows an example of the resource allocation of DMRS included in a PDCCH. Figure 7(a) shows an example of DMRS allocation in the case of a 1-symbol CORESET. Figure 7(b) shows an example of DMRS allocation in the case of a 2-symbol CORESET. Figure 7(c) shows an example of DMRS allocation in the case of a 3-symbol CORESET. As shown in Figure 7, the DMRS are arranged frequency-discontinuously within the PDCCH.

[0086] Figure 8 shows an example of DMRS resource allocation within a PBCH. Figure 8(a) shows an example of DMRS allocation when PCI=0. Figure 8(b) shows an example of DMRS allocation when PCI=1. Figure 8(c) shows an example of DMRS allocation when PCI=2. Figure 8(d) shows an example of DMRS allocation when PCI=3. As shown in Figure 8, the DMRS is allocated within the PBCH in a frequency-discontinuous manner.

[0087] Thus, in 5G NR and other technologies, some signals are arranged discontinuously in the frequency domain. When transmitting these signals, there is a risk that PAPR (Periodic Action Restriction) will increase.

[0088] <1-3. Overview of the proposed technology> Figure 9 shows an example of communication processing related to the proposed technology of this disclosure. The communication processing related to this proposed technology is performed by a base station 20 that communicates with a terminal device.

[0089] The base station 20 generates signals for the first to Xth physical channels (step S101). The base station 20 may generate multiple signals. For example, the base station 20 may generate signals for each of the multiple (X) physical channels, or it may generate multiple signals contained within a single physical channel. Alternatively, the base station 20 may generate one or more signals contained within each of the multiple physical channels.

[0090] The base station 20 applies a first resource mapping to multiple signals (in this case, signals from the first to the Xth physical channels) to map the multiple signals to time resources or logical resources (step S102). As a result, the multiple signals are multiplexed.

[0091] The base station 20 performs a Fourier transform (in this case, a discrete Fourier transform (or fast Fourier transform)) on multiple signals to which the first resource mapping has been applied to generate a first transformed signal (step S103).

[0092] The base station 20 applies a second resource mapping to the first converted signal to map the first converted signal to frequency resources and time resources (step S104).

[0093] The base station 20 generates a second transformed signal by applying an inverse Fourier transform (in this case, an inverse fast Fourier transform (or fast Fourier transform)) to the first transformed signal to which the second resource mapping has been applied (step S105).

[0094] The base station 20 performs downlink transmission by generating a downlink signal to which a single-carrier modulation scheme is applied from the second converted signal and transmitting it to the terminal device (step S106).

[0095] The base station 20 according to the proposed technology multiplexes multiple signals in a first resource mapping to generate a downlink signal to which a single-carrier modulation scheme is applied. As a result, multiple signals are less likely to be placed discontinuously in the frequency domain, and the base station 20 can further reduce PAPR.

[0096] Patent Document 1 discloses a control channel transmission means when a single carrier is applied to the downlink signal. Patent Document 1 discloses a means for transmission using a first frequency resource for reference signal transmission and a second frequency resource for control channel transmission. In Patent Document 1, resource mapping is performed only with frequency resources, and no technique for resource mapping to time resources or logic resources is disclosed.

[0097] Non-Patent Document 1 discloses a means for applying Discrete Fourier Transform (DFT) processing to a downlink synchronization signal to map it to frequency resources. This Non-Patent Document 1 provides a technique for transmitting a single synchronization signal as a single carrier, and does not disclose any technique for multiplexing multiple signals.

[0098] As described above, the base station 20 according to the proposed technology of this disclosure performs a first resource mapping before discrete Fourier transform (DFT) processing to multiplex multiple signals. This allows the base station 20 to further reduce PAPR.

[0099] In the following embodiments, the base station 20 can be a ground base station, a satellite station, or a non-ground base station 30 that operates as a communication device, such as a drone, balloon, or airplane.

[0100] Furthermore, in the following embodiments, while specific values ​​are given to illustrate concrete examples, other values ​​may be used instead.

[0101] Furthermore, in this embodiment, resources represent Frequency, Time, Resource Element (including REG, CCE, and CORESET), Resource Block, Bandwidth Part, Component Carrier, Symbol, Sub-Symbol, Slot, Mini-Slot, Non-slot, Subslot, Subframe, Frame, PRACH occasion, Occasion, Code, Multi-access physical resource, Multi-access signature, Subcarrier Spacing (Numerology), and the like.

[0102] Furthermore, if the single-carrier scheme is not applicable, the base station 20 transmits the downlink signal using, for example, a multi-carrier scheme. An example of a multi-carrier scheme is CP-OFDM. An example of a single-carrier scheme is DFT-S-OFDM. Note that CP-OFDM and DFT-S-OFDM are just examples, and the multi-carrier and single-carrier schemes are not limited to these.

[0103] As mentioned above, in the single-carrier system, transform precoding is applied to the transmitted signal processing, while in the multi-carrier system, transform precoding is not applied.

[0104] Therefore, processing related to the single-carrier scheme (DFT-S-OFDM) can be reinterpreted as processing to which Transform precoding is applied. Conversely, processing related to the multi-carrier scheme (CP-OFDM) can be reinterpreted as processing to which Transform precoding is not applied.

[0105] <<2. Example of a communication system configuration>> <2-1. Example of overall communication system configuration> Figure 10 is a diagram illustrating an example of the overall configuration of a communication system SYS1 according to the present disclosure. As shown in Figure 10, the communication system SYS1 according to this embodiment includes a base station 20 and a plurality of terminal devices 50A, 50B.

[0106] The communication system SYS1 may also include a management device 10, a non-terrestrial station 30, a relay station 40 (see Figure 2), etc.

[0107] (Base station 20) Base station 20 is a communication device that operates cell C1 and provides wireless communication services to one or more terminal devices 50 located within the coverage of cell C1. Cell C1 operates according to any wireless communication method, such as LTE or NR. Base station 20 is connected to the core network. The core network is connected to the packet data network (not shown) via a gateway device (not shown). Base station 20 also operates beams identifiable by SSB (Synchronization Signal / PBCH Block) and can send and receive data to and from one or more terminal devices 50 via one or more beams.

[0108] The base station 20 may be composed of a collection of multiple physical or logical devices. For example, in this embodiment, the base station 20 may be distinguished into multiple devices of BBU (Baseband Unit) and RU, and may be interpreted as a collection of these multiple devices. Alternatively, in this embodiment, the base station 20 may be either or both of the BBU and RU. The BBU and RU may be connected by a predetermined interface (e.g., eCPRI). Alternatively, the RU may be referred to as a Remote Radio Unit (RRU) or Radio DoT (RD). Alternatively, the RU may correspond to a gNB-DU described later. Alternatively, the BBU may correspond to a gNB-CU described later. Alternatively, the RU may be connected to a gNB-DU described later. Alternatively, the BBU may correspond to a combination of gNB-CU and gNB-DU described later. Alternatively, the RU may be a device formed integrally with an antenna. The antenna of the base station 20 (for example, an antenna formed integrally with the RU) may employ an Advanced Antenna System and support MIMO (for example, FD-MIMO) and beamforming. The Advanced Antenna System may include, for example, 64 transmitting antenna ports and 64 receiving antenna ports.

[0109] Furthermore, multiple base stations 20 may be connected to each other. One or more base stations 20 may be included in a Radio Access Network (RAN). That is, base stations 20 may simply be referred to as RAN, RAN node, AN (Access Network), or AN node. In LTE, the RAN is called EUTRAN (Enhanced Universal Terrestrial RAN). In NR, the RAN is called NGRAN. In W-CDMA (UMTS), the RAN is called UTRAN. In LTE, base stations 20 are referred to as eNodeB (Evolved Node B) or eNB. That is, EUTRAN includes one or more eNodeB (eNB). Also, in NR, base stations 20 are referred to as gNodeB or gNB. That is, NGRAN includes one or more gNB. Furthermore, EUTRAN may include gNB (en-gNB) connected to the core network (EPC) in the LTE communication system (EPS). Similarly, NGRAN may include ng-eNB connected to the core network 5GC in the 5G communication system (5GS). Furthermore, or alternatively, if base station 20 is an eNB, gNB, etc., it may be referred to as 3GPP Access. Furthermore, or alternatively, if base station 20 is a radio access point (e.g., a WiFi® access point), it may be referred to as Non-3GPP Access. Furthermore, or alternatively, base station 20 may be an optical extension device called an RRH (Remote Radio Head). Furthermore, or alternatively, if base station 20 is a gNB, base station 20 may be referred to as a combination of the gNB CU (Central Unit) and gNB DU (Distributed Unit) described above, or either of these. The gNB CU hosts multiple upper layers (e.g., RRC, SDAP, PDCP) of the Access Stratum for communication with the UE. On the other hand, the gNB-DU hosts multiple lower layers (e.g., RLC, MAC, PHY) of the Access Stratum.In other words, among the messages and information described later, RRC signalling (e.g., MIB, various SIBs including SIB1, RRCSetup message, RRCReconfiguration message) may be generated by the gNB CU, while DCI and various Physical Channels (e.g., PDCCH, PBCH) described later may be generated by the gNB-DU. Alternatively, among the RRC signalling, some configuration information, such as IE:cellGroupConfig, may be generated by the gNB-DU, and the remaining configuration information may be generated by the gNB-CU. These configuration information may be transmitted and received via the F1 interface described later. Base station 20 may be configured to communicate with other base stations 20. For example, if multiple base stations 20 are eNBs or a combination of eNB and en-gNB, the base stations 20 may be connected via the X2 interface. Furthermore, or alternatively, if multiple base stations 20 are gNBs or a combination of gn-eNB and gNB, the devices may be connected via the Xn interface. Furthermore, or alternatively, if multiple base stations 20 are a combination of gNB CUs and gNB DUs, the devices may be connected to each other via the F1 interface described above. The messages and information described later (RRC signalling or DCI information, Physical Channel) may be communicated between the multiple base stations 20 (for example, via the X2, Xn, and F1 interfaces).

[0110] Furthermore, as mentioned above, the base station 20 may be configured to manage multiple cells C1. A cell C1 provided by the base station 20 is called a Serving cell. A Serving cell includes a PCell (Primary Cell) and an SCell (Secondary Cell). When Dual Connectivity (e.g., EUTRA-EUTRA Dual Connectivity, EUTRA-NR Dual Connectivity (ENDC), EUTRA-NR Dual Connectivity with 5GC, NR-EUTRA Dual Connectivity (NEDC), NR-NR Dual Connectivity) is provided to a UE (e.g., terminal device 50), the PCell and zero or more SCell(s) provided by the MN (Master Node) are called a Master Cell Group. Furthermore, a Serving cell may also include a PSCell (Primary Secondary Cell or Primary SCG Cell). That is, when Dual Connectivity is provided to a UE, the PSCell and zero or more SCell(s) provided by the SN (Secondary Node) are called a Secondary Cell Group (SCG). Unless otherwise specified (e.g., PUCCH on SCell), the Physical Uplink Control Channel (PUCCH) is transmitted by PCell and PSCell, but not by SCell. Similarly, Radio Link Failure is detected by PCell and PSCell, but not by SCell (and does not need to be detected). Because PCell and PSCell have special roles within Serving Cell(s), they are also called Special Cells (SpCell). A single cell C1 may be associated with one Downlink Component Carrier and one Uplink Component Carrier. Furthermore, the system bandwidth corresponding to a single cell C1 may be divided into multiple Bandwidth Parts.In this case, one or more Bandwidth Parts (BWPs) may be configured for the UE, and one Bandwidth Part may be used by the UE as the Active BWP. Furthermore, the radio resources (e.g., frequency band, numerology (subcarrier spacing), slot format) available to the terminal device 50 may differ for each cell C1, each component carrier, or each BWP.

[0111] The base station 20 uses, for example, a single-carrier system for downlink communication with the terminal device 50.

[0112] The base station 20 may, for example, determine the signal waveform to be used for each terminal device 50. In the example shown in Figure 10, the base station 20 may select a multi-carrier signal to perform downlink communication S1 with terminal device 50A located near the center of cell C1. The base station 20 may also select a single-carrier signal to perform downlink communication S2 with terminal device 50B located near the edge of cell C1.

[0113] To perform downlink communication with terminal device 50B located near the cell edge, a larger transmit power is required, thus demanding a lower PAPR. On the other hand, for terminal device 50A located near the center of cell C1, the required transmit power is smaller compared to the cell edge, making it easier to secure the necessary transmit power even with a higher PAPR.

[0114] Therefore, the base station 20 selects a multi-carrier signal for terminal device 50A located near the center of cell C1, and a single-carrier signal for terminal device 50B located near the edge of cell C1.

[0115] In this way, the base station 20 assigns a single-carrier signal to downlink communications where low PAPR is strictly required, and assigns a signal waveform other than a single-carrier signal (in this case, a multi-carrier signal) to downlink communications where the low PAPR requirement is less stringent. As a result, the base station 20 can achieve low PAPR and improved overall system efficiency.

[0116] In this explanation, the base station 20 determines the signal waveform according to the position of the terminal device 50 in cell C1, but the method by which the base station 20 determines the signal waveform is not limited to this. Furthermore, the base station 20 may assign the same signal waveform, such as assigning a single-carrier signal, to all terminal devices 50 in cell C1.

[0117] <2-2. Example of base station configuration> Figure 11 is a block diagram showing an example configuration of a base station 20 according to an embodiment of the present disclosure. As shown in Figure 11, the base station 20 includes an upper layer processing unit 101, a control unit 103, a receiving unit 105, a transmitting unit 107, and a transmitting / receiving antenna 109.

[0118] The base station 20 may support one or more RATs (Radio Access Technologies). For example, the base station 20 may support both LTE and NR. In this case, some or all of the parts included in the base station 20 may be configured individually according to the RAT. For example, the receiving unit 105 and the transmitting unit 107 may be configured individually for LTE and NR.

[0119] Furthermore, in an NR cell, some or all of the components included in the base station 20 shown in Figure 11 may be configured individually according to the parameter set for the transmitted signal. For example, in a given NR cell, the radio receiver 1057 and the radio transmitter 1077 may be configured individually according to the parameter set for the transmitted signal.

[0120] (Upper layer processing unit) The upper layer processing unit 101 outputs downlink data (transport blocks) to the control unit 103. The upper layer processing unit 101 performs processing at the Medium Access Control (MAC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Radio Resource Control (RRC) layer. In addition, the upper layer processing unit 101 generates control information to control the receiver 105 and the transmitter 107 and outputs it to the control unit 103.

[0121] The upper layer processing unit 101 performs processing and management related to RAT control, wireless resource control, subframe setting, scheduling control, and / or CSI reporting control. The processing and management in the upper layer processing unit 101 are performed for each terminal device 50, or in common for all terminal devices 50 connected to the base station 20.

[0122] The processing and management in the upper layer processing unit 101 may be performed solely by the upper layer processing unit 101, or it may be obtained from an upper node or another base station 20. Furthermore, the processing and management in the upper layer processing unit 101 may be performed individually according to the RAT. For example, the upper layer processing unit 101 may perform processing and management for LTE and processing and management for NR separately.

[0123] In the upper layer processing unit 101, RAT control is performed, which includes management related to RAT. For example, RAT control includes management related to LTE and / or NR. Management related to NR includes setting and processing parameter sets related to the transmission signal in NR cells.

[0124] In the upper layer processing unit 101, wireless resource control is performed, which manages the configuration information of the device itself. In the upper layer processing unit 101, wireless resource control is performed, which generates and / or manages downlink data (transport blocks), system information, RRC messages (RRC parameters), and / or MAC control elements (CE: Control Elements).

[0125] In the upper layer processing unit 101, subframe settings are managed, including subframe settings, subframe pattern settings, uplink and downlink settings, uplink reference UL-DL settings, and / or downlink reference UL-DL settings.

[0126] The subframe settings in the upper layer processing unit 101 are also referred to as base station subframe settings. Furthermore, the subframe settings in the upper layer processing unit 101 can be determined based on the traffic volume of the uplink and the traffic volume of the downlink.

[0127] Furthermore, the subframe settings in the upper layer processing unit 101 can be determined based on the scheduling results of the scheduling control in the upper layer processing unit 101.

[0128] In the scheduling control in the upper layer processing unit 101, the frequency and subframe to which the physical channel is assigned, the coding rate and modulation scheme of the physical channel, and the transmission power are determined based on the received channel status information and the estimated propagation path and channel quality input from the channel measurement unit 1059. For example, the control unit 103 generates control information (DCI format) based on the scheduling result of the scheduling control in the upper layer processing unit 101.

[0129] In the upper-layer processing unit 101, CSI reporting control is performed to control the CSI reporting of the terminal device 50. For example, settings related to the CSI reference resources assumed for calculating the CSI in the terminal device 50 are controlled.

[0130] (Control Unit) The control unit 103 controls the receiving unit 105 and the transmitting unit 107 based on control information from the upper layer processing unit 101. The control unit 103 generates control information for the upper layer processing unit 101 and outputs it to the upper layer processing unit 101.

[0131] The control unit 103 receives the decoded signal from the decoding unit 1051 and the channel estimation result from the channel measurement unit 1059. The control unit 103 outputs the signal to be encoded to the encoding unit 1071. The control unit 103 is also used to control all or part of the base station 20.

[0132] Furthermore, the control unit 103 determines the signal waveform (hereinafter also referred to as the "used signal waveform") to be used for downlink communication with the terminal device 50 from among the single-carrier signal and multi-carrier signal.

[0133] The control unit 103 controls the transmission unit 107 to notify the terminal device 50 of information regarding the signal waveform being used using a predetermined signal waveform (e.g., a single-carrier signal). The control unit 103 also controls the transmission unit 107 to perform downlink communication with the terminal device 50 using the notified signal waveform being used.

[0134] (Receiving unit) The receiving unit 105 receives signals transmitted from the terminal device 50 via the transmitting / receiving antenna 109 in accordance with the control unit 103, performs reception processing such as separation, demodulation, and decoding, and outputs the processed information to the control unit 103.

[0135] The reception processing in the receiving unit 105 is performed based on predetermined settings or settings notified to the terminal device 50 by the base station 20.

[0136] The receiving unit 105 includes a decoding unit 1051, a demodulation unit 1053, a multiplexing / decoupling unit 1055, a wireless receiving unit 1057, and a channel measurement unit 1059.

[0137] (Wireless receiver) The wireless receiver 1057 performs the following operations on the uplink signal received via the transmitting and receiving antenna 109: downconversion to an intermediate frequency, removal of unwanted frequency components, control of the amplification level to maintain an appropriate signal level, quadrature demodulation based on the common-mode and quadrature components of the received signal, conversion from an analog signal to a digital signal, removal of the guard interval (GI), and / or extraction of the frequency domain signal by fast Fourier transform (FFT).

[0138] (Demultiplexer) The multiplexing / decoupling unit 1055 separates the uplink channel, such as PUCCH or PUSCH, and / or the uplink reference signal from the signal input from the wireless receiving unit 1057. The multiplexing / decoupling unit 1055 outputs the uplink reference signal to the channel measurement unit 1059. The multiplexing / decoupling unit 1055 compensates the propagation path for the uplink channel based on the estimated propagation path value input from the channel measurement unit 1059.

[0139] (Demodulation unit) The demodulation unit 1053 demodulates the received signal using modulation schemes such as BPSK (Binary Phase Shift Keying), π / 2BPSK, QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), 64QAM, and 256QAM for the modulation symbols of the uplink channel. The demodulation unit 1053 also separates and demodulates the MIMO multiplexed uplink channel.

[0140] (Decoding unit) The decoding unit 1051 performs decoding on the encoded bits of the demodulated uplink channel. The decoded uplink data and / or uplink control information is output to the control unit 103. The decoding unit 1051 performs decoding on each transport block for PUSCH.

[0141] (Channel measurement unit) The channel measurement unit 1059 measures the estimated propagation path and / or channel quality from the uplink reference signal input from the multiplexing / decoupling unit 1055, and outputs it to the multiplexing / decoupling unit 1055 and / or the control unit 103. For example, the channel measurement unit 1059 measures the estimated propagation path for propagation path compensation for PUCCH or PUSCH using UL-DMRS, and measures the channel quality in the uplink using SRS.

[0142] (Transmitter) The transmitting unit 107 performs transmission processing such as encoding, modulation, and multiplexing on the downlink control information and downlink data input from the upper layer processing unit 101, in accordance with the control from the control unit 103. For example, the transmitting unit 107 generates and multiplexes PHICH, PDCCH, EPDCCH, PDSCH, and downlink reference signals to generate a transmission signal.

[0143] The transmission process in the transmitting unit 107 is performed based on predetermined settings, settings notified by the base station 20 to the terminal device 50, or settings notified via PDCCH or EPDCCH transmitted in the same subframe.

[0144] The transmitting unit 107 includes an encoding unit 1071, a modulation unit 1073, a multiplexing unit 1075, a wireless transmitting unit 1077, and a downlink reference signal generation unit 1079.

[0145] (encoding section) The encoding unit 1071 encodes the HARQ indicator (HARQ-ACK), downlink control information, and downlink data input from the control unit 103 using a predetermined encoding method such as block encoding, convolutional encoding, or turbo encoding.

[0146] (Modulation section) The modulation unit 1073 modulates the encoded bits input from the encoding unit 1071 using a predetermined modulation scheme such as BPSK, π / 2BPSK, QPSK, 16QAM, 64QAM, or 256QAM.

[0147] (Downlink reference signal generation unit) The downlink reference signal generation unit 1079 generates a downlink reference signal based on the physical cell identification (PCI), RRC parameters set in the terminal device 50, and the like.

[0148] (Multiple part) The multiplexer 1075 multiplexes the modulation symbols and downlink reference signals for each channel and places them in predetermined resource elements. When downlink communication is performed using a second signal waveform (single-carrier signal), the multiplexer 1075 performs, for example, a first resource mapping, mapping multiple signals to time resources or logic resources. The multiplexer 1056 then performs a Fast Fourier Transform or Discrete Fourier Transform on the mapped signals. The multiplexer 1075 then performs a second resource mapping on the signals that have undergone the Fast Fourier Transform or Discrete Fourier Transform.

[0149] (Wireless transmission unit) The wireless transmitter 1077 converts the signal from the multiplexer 1075 into a time-domain signal using an inverse fast Fourier transform (IFFT), adds a guard interval, and generates a baseband digital signal. The wireless transmitter 1077 also performs processing such as conversion to an analog signal, quadrature modulation, conversion from an intermediate frequency signal to a high-frequency signal (upconversion), removal of extraneous frequency components, and power amplification to generate the transmission signal. The transmission signal output by the wireless transmitter 1077 is transmitted from the transmitting and receiving antenna 109.

[0150] Here, the wireless transmitter 1077 according to this embodiment can support multiple downlink signal waveforms. Figures 12 to 14 will be used to describe in detail the wireless transmitter 1077 in the base station 20 that supports both a first signal waveform (multi-carrier signal) and a second signal waveform (single-carrier signal).

[0151] Figure 12 is a block diagram showing an example configuration of a wireless transmission unit 1077 according to an embodiment of the present disclosure. The wireless transmission unit 1077 includes a signal waveform switching unit 401, a first signal waveform transmission unit 403, and a second signal waveform transmission unit 405.

[0152] The signal waveform switching unit 401 switches whether the downlink communication to be transmitted is a first signal waveform or a second signal waveform, depending on predetermined conditions or circumstances.

[0153] If the downlink communication to be transmitted is of the first signal waveform, the downlink communication is processed for transmission by the first signal waveform transmission unit 403. If the downlink communication to be transmitted is of the second signal waveform, the downlink communication is processed for transmission by the second signal waveform transmission unit 405. The conditions and circumstances for switching in the signal waveform switching unit 401 will be described later.

[0154] The signal waveform switching unit 401 is also referred to as the signal waveform control unit. In Figure 12, the first signal waveform transmission unit 403 and the second signal waveform transmission unit 405 are shown as different processing units, but they may also be treated as a single processing unit, with only a portion of the transmission process being switched.

[0155] Figure 13 is a block diagram showing an example configuration of a first signal waveform transmission unit 403 according to an embodiment of the present disclosure. The first signal waveform transmission unit 403 performs transmission processing on the downlink channel and signal to be transmitted by CP-OFDM as a signal waveform for uplink communication. The first signal waveform transmission unit 403 includes an S / P unit 4031, an IDFT (Inverse Discrete Fourier Transform) unit 4033, a P / S unit 4035, and a CP insertion unit 4037.

[0156] The S / P unit 4031 converts the input serial signal into a parallel signal of size M. Here, size M is determined depending on the size of the frequency domain resource used for downlink communication. The parallel signal of size M is input to the IDFT unit 4033 so as to correspond to a predetermined frequency domain.

[0157] The IDFT unit 4033 performs an inverse Fourier transform on a parallel signal of size N. Here, if size N is exponential 2, the Fourier transform can be performed using IFFT (Inverse Fast Fourier Transform). The P / S unit 4035 converts the parallel signal of size N into a serial signal. The CP insertion unit 4037 inserts a predetermined CP for each OFDM symbol.

[0158] Figure 14 is a block diagram showing an example configuration of a second signal waveform transmission unit 405 according to an embodiment of the present disclosure. The second signal waveform transmission unit 405 performs transmission processing on the downlink channel and signal to be transmitted as a signal waveform for downlink communication, for example by DFT-S-OFDM.

[0159] The second signal waveform transmission unit 405 comprises a DFT unit 4051, an IDFT unit 4053, a P / S unit 4055, and a CP insertion unit 4057. The DFT unit 4051 performs DFT conversion on a parallel signal of size M. Here, size M is determined depending on the size of the frequency domain resources used for downlink communication. The parallel signal of size M is input to the IDFT unit 4053 so as to correspond to a predetermined frequency domain.

[0160] The IDFT unit 4053 performs an inverse Fourier transform on a parallel signal of size N. Here, if size N is an exponent of 2, the Fourier transform can be performed using an IFFT. The P / S unit 4055 converts the parallel signal of size N into a serial signal. The CP insertion unit 4057 inserts a predetermined CP for each DFT-S-OFDM symbol.

[0161] <2-3. Example of terminal device configuration> Next, the configuration of the terminal device 50 will be explained. The terminal device 50 can also be referred to as UE (User Equipment) 50.

[0162] Terminal device 50 is a communication device that wirelessly communicates with other communication devices such as base station 20. Examples of terminal devices 50 include mobile phones, smart devices (smartphones or tablets), PDAs (Personal Digital Assistants), and personal computers. Terminal device 50 may also be a professional camera equipped with communication functions, or a motorcycle or mobile relay vehicle equipped with communication devices such as an FPU (Field Pickup Unit). Furthermore, terminal device 50 may be an M2M (Machine to Machine) device or an IoT (Internet of Things) device.

[0163] The terminal device 50 may be capable of NOMA communication with the base station 20. Furthermore, the terminal device 50 may use automatic retransmission technology such as HARQ when communicating with the base station 20. The terminal device 50 may be capable of sidelink communication with other terminal devices 50. The terminal device 50 may also use automatic retransmission technology such as HARQ when performing sidelink communication. Furthermore, the terminal device 50 may be capable of NOMA communication even when communicating with other terminal devices 50 (sidelink). Furthermore, the terminal device 50 may be capable of LPWA communication with other communication devices (for example, the base station 20 and other terminal devices 50). Furthermore, the wireless communication used by the terminal device 50 may be millimeter-wave wireless communication. Furthermore, the wireless communication used by the terminal device 50 (including sidelink communication) may be radio wave wireless communication, or infrared or visible light wireless communication (optical wireless).

[0164] Furthermore, the terminal device 50 may be mounted on a mobile device. The mobile device is a portable wireless communication device. For example, the terminal device 50 may be a vehicle that moves on roads, such as an automobile, bus, truck, or motorcycle; a vehicle that moves on rails installed on tracks, such as a train; or a wireless communication device mounted on such a vehicle. The mobile device may be a mobile terminal, or a mobile device that moves on land (ground in the narrow sense), underground, on water, or underwater. The mobile device may also be a mobile device that moves within the atmosphere, such as a drone or helicopter, or a mobile device that moves outside the atmosphere, such as an artificial satellite.

[0165] The terminal device 50 may simultaneously connect to and communicate with multiple base stations 20 or multiple cells. For example, if one base station 20 supports a communication area via multiple cells (e.g., pCell, sCell), it is possible to combine these multiple cells using carrier aggregation (CA), dual connectivity (DC), or multi-connectivity (MC) technologies to enable communication between the base station 20 and the terminal device 50. Alternatively, the terminal device 50 can communicate with multiple base stations 20 via cells of different base stations 20 using coordinated multi-point transmission and reception (CoMP) technology.

[0166] Figure 15 is a block diagram showing an example configuration of a terminal device 50 according to an embodiment of the present disclosure. As shown in Figure 15, the terminal device 50 includes a higher layer processing unit 201, a control unit 203, a receiving unit 205, a transmitting unit 207, and a transmitting / receiving antenna 209.

[0167] The terminal device 50 may support one or more RATs. For example, the terminal device 50 may support both LTE and NR. In this case, some or all of the parts included in the terminal device 50 may be configured individually according to the RAT. For example, the receiving unit 205 and the transmitting unit 207 may be configured individually for LTE and NR. Also, in an NR cell, some or all of the parts included in the terminal device 50 shown in Figure 15 may be configured individually according to the parameter set for the transmission signal. For example, in a certain NR cell, the wireless receiving unit 2057 and the wireless transmitting unit 2077 may be configured individually according to the parameter set for the transmission signal.

[0168] (Upper layer processing unit) The upper layer processing unit 201 outputs the uplink data (transport block) to the control unit 203. The upper layer processing unit 201 performs processing for the media access control layer, packet data integration protocol layer, wireless link control layer, and wireless resource control layer. In addition, the upper layer processing unit 201 generates control information to control the receiving unit 205 and the transmitting unit 207 and outputs it to the control unit 203.

[0169] The upper layer processing unit 201 performs processing and management related to RAT control, radio resource control, subframe setting, scheduling control, and / or CSI reporting control. The processing and management in the upper layer processing unit 201 are performed based on predetermined settings and / or settings based on control information set or notified from the base station 20.

[0170] For example, control information from base station 20 includes RRC parameters, MAC control elements, or DCI. Furthermore, processing and management in the upper layer processing unit 201 may be performed separately according to the RAT. For example, the upper layer processing unit 201 may perform processing and management for LTE and processing and management for NR separately.

[0171] In the upper layer processing unit 201, RAT control is performed, which includes management related to RAT. For example, RAT control includes management related to LTE and / or NR. Management related to NR includes setting and processing parameter sets related to the transmission signal in NR cells.

[0172] In the upper layer processing unit 201, wireless resource control is performed, which manages the configuration information of the device itself. In the upper layer processing unit 201, wireless resource control is performed, which generates and / or manages uplink data (transport blocks), system information, RRC messages (RRC parameters), and / or MAC control elements (CE).

[0173] In the subframe settings of the upper layer processing unit 201, the subframe settings of base station 20 and / or base stations other than base station 20 are managed. The subframe settings include uplink or downlink settings for subframes, subframe pattern settings, uplink / downlink settings, uplink reference UL-DL settings, and / or downlink reference UL-DL settings. The subframe settings in the upper layer processing unit 201 are also referred to as terminal subframe settings.

[0174] In the scheduling control of the upper layer processing unit 201, control information is generated for performing scheduling control on the receiving unit 205 and the transmitting unit 207 based on the DCI (scheduling information) from the base station 20.

[0175] In the upper layer processing unit 201, CSI reporting control is performed to control the reporting of CSI to the base station 20. For example, CSI reporting control controls the settings related to the CSI reference resource assumed for calculating the CSI in the channel measurement unit 2059. CSI reporting control controls the resources (timing) used to report the CSI based on DCI and / or RRC parameters.

[0176] (Control Unit) The control unit 203 controls the receiving unit 205 and the transmitting unit 207 based on control information from the upper layer processing unit 201. The control unit 203 generates control information for the upper layer processing unit 201 and outputs it to the upper layer processing unit 201. The control unit 203 receives the decoded signal from the decoding unit 2051 and the channel estimation result from the channel measurement unit 2059. The control unit 203 outputs the signal to be encoded to the encoding unit 2071. The control unit 203 may also be used to control the entirety or a part of the terminal device 50.

[0177] Furthermore, the control unit 203 acquires information from the base station 20 via the receiving unit 205 regarding the signal waveform to be used for downlink communication with the base station 20, among single-carrier and multi-carrier signals. The information regarding the signal waveform to be used is information transmitted with a predetermined signal waveform (for example, a single-carrier signal). The control unit 203 controls the receiving unit 205 to perform downlink communication with the base station 20 using the signal waveform to be used.

[0178] (Receiving unit) The receiving unit 205 receives signals transmitted from the base station 20 via the transmitting / receiving antenna 209 in accordance with the control unit 203, and further performs reception processing such as separation, demodulation, and decoding, and outputs the processed information to the control unit 203. The reception processing in the receiving unit 205 is performed based on predetermined settings or notifications or settings from the base station 20. The receiving unit 205 includes a decoding unit 2051, a demodulation unit 2053, a multiplexing / decoupling unit 2055, a wireless receiving unit 2057, and a channel measurement unit 2059.

[0179] (Wireless receiver) The wireless receiver 2057 performs the following operations on the uplink signal received via the transmitting and receiving antenna 209: down-conversion to an intermediate frequency, removal of unwanted frequency components, and control of the amplification level to maintain an appropriate signal level. The wireless receiver 2057 also performs quadrature demodulation based on the common-mode and quadrature components of the received signal, conversion from analog to digital signal, removal of guard intervals, and / or extraction of the frequency domain signal using a fast Fourier transform.

[0180] Here, the wireless receiver 2057 according to this embodiment can support multiple uplink signal waveforms. Figures 16 to 18 will be used to describe the details of the wireless receiver 2057 in the terminal device 50 that supports both a first signal waveform (multi-carrier signal) and a second signal waveform (single-carrier signal).

[0181] Figure 16 is a block diagram showing an example configuration of a wireless receiving unit 2057 according to an embodiment of the present disclosure. The wireless receiving unit 2057 includes a signal waveform switching unit 301, a first signal waveform receiving unit 303, and a second signal waveform receiving unit 305.

[0182] The signal waveform switching unit 301 switches whether the received downlink communication is a first signal waveform or a second signal waveform, depending on predetermined conditions or circumstances. If the received downlink communication is a first signal waveform, it is received and processed by the first signal waveform receiving unit 303. If the received downlink communication is a second signal waveform, it is received and processed by the second signal waveform receiving unit 305.

[0183] In Figure 16, the first signal waveform receiving unit 303 and the second signal waveform receiving unit 305 are shown as different processing units, but they may also be treated as a single processing unit, with only a portion of the reception processing being switched between.

[0184] Figure 17 is a block diagram showing an example configuration of a first signal waveform receiving unit 303 according to an embodiment of the present disclosure. The first signal waveform receiving unit 303 performs reception processing on the downlink channel and signal transmitted by CP-OFDM as a signal waveform for downlink communication. The first signal waveform receiving unit 303 includes a CP removal unit 3031, an S / P unit 3033, a DFT unit 3035, and a P / S unit 3037.

[0185] The CP removal unit 3031 removes the CP (Cyclic prefix) added to the received downlink communication. The S / P unit 3033 converts the input serial signal into a parallel signal of size N. The DFT unit 3035 performs a Fourier transform. Here, if the size N is an exponent of 2, the Fourier transform can be performed using an FFT.

[0186] The P / S unit 3037 converts the input parallel signal of size M into a serial signal. Here, the P / S unit 3037 receives the downlink communication signal transmitted by the terminal device 50 that performs the receiving processing. The size M is determined depending on the size of the frequency domain resource used for the downlink communication.

[0187] Figure 18 is a block diagram showing an example configuration of a second signal waveform receiving unit 305 according to an embodiment of the present disclosure. The second signal waveform receiving unit 305 performs reception processing on downlink channels and signals transmitted as signal waveforms for downlink communication, for example by DFT-S-OFDM. The second signal waveform receiving unit 305 includes a CP removal unit 3051, an S / P unit 3053, a DFT unit 3055, and an IDFT unit 3057.

[0188] The CP removal unit 3051 removes CP added to the received downlink communication. The S / P unit 3053 converts the input serial signal into a parallel signal of size N. The DFT unit 3055 performs a Fourier transform. Here, if the size N is an exponent of 2, the Fourier transform can be performed using an FFT.

[0189] The IDFT unit 3057 performs an inverse Fourier transform on the input signal of size M. Here, the IDFT unit 3057 receives the downlink communication signal transmitted by the terminal device 50 that performs the receiving process. The size M is determined depending on the size of the frequency domain resources used for the downlink communication.

[0190] (Demultiplexer) Returning to Figure 15, the multiplexing / decoupling unit 2055 separates downlink channels such as PHICH, PDCCH, EPDCCH, or PDSCH, downlink synchronization signals, and / or downlink reference signals from the signals input from the wireless receiving unit 2057.

[0191] When downlink communication is performed using a second signal waveform (single-carrier signal), the multiplexing / decoupling unit 2055 performs, for example, a first resource demapping to separate multiple signals from the downlink communication signal.

[0192] The multiplexing / decoupling unit 2055 outputs a downlink reference signal to the channel measurement unit 2059. The multiplexing / decoupling unit 2055 compensates the downlink channel for the propagation path based on the estimated propagation path input from the channel measurement unit 2059.

[0193] (Demodulation unit) The demodulation unit 2053 demodulates the received signal using modulation schemes such as BPSK, π / 2BPSK, QPSK, 16QAM, 64QAM, and 256QAM for the modulation symbols of the downlink channel. The demodulation unit 2053 also separates and demodulates the MIMO multiplexed downlink channel.

[0194] (Decoding unit) The decoding unit 2051 performs decoding on the encoded bits of the demodulated downlink channel. The decoded downlink data and / or downlink control information is output to the control unit 203. The decoding unit 2051 performs decoding on each transport block of the PDSCH.

[0195] (Channel measurement unit) The channel measurement unit 2059 measures the estimated propagation path and / or channel quality from the downlink reference signal input from the multiplexing / decoupling unit 2055, and outputs it to the multiplexing / decoupling unit 2055 and / or the control unit 203.

[0196] The downlink reference signal used by the channel measurement unit 2059 for measurement may be determined based on the transmission mode set by at least the RRC parameters and / or other RRC parameters.

[0197] For example, DL-DMRS measures the estimated propagation path for propagation path compensation for PDSCH or EPDCCH. CRS measures the estimated propagation path for propagation path compensation for PDCCH or PDSCH, and / or the channel on the downlink for reporting CSI. CSI-RS measures the channel on the downlink for reporting CSI.

[0198] The channel measurement unit 2059 calculates RSRP (Reference Signal Received Power) and / or RSRQ (Reference Signal Received Quality) based on CRS, CSI-RS, or the detection signal, and outputs them to the upper layer processing unit 201.

[0199] (Transmitter) The transmitting unit 207 performs transmission processing such as encoding, modulation, and multiplexing on the uplink control information and uplink data input from the upper layer processing unit 201, in accordance with the control from the control unit 203. For example, the transmitting unit 207 generates and multiplexes an uplink channel and / or uplink reference signal such as PUSCH or PUCCH to generate a transmission signal.

[0200] The transmission process in the transmitting unit 207 is performed based on predetermined settings or settings or notifications from the base station 20. The transmitting unit 207 includes an encoding unit 2071, a modulation unit 2073, a multiplexing unit 2075, a wireless transmission unit 2077, and an uplink reference signal generation unit 2079.

[0201] (encoding section) The encoding unit 2071 encodes the HARQ indicator (HARQ-ACK), uplink control information, and uplink data input from the control unit 203 using a predetermined encoding method such as block encoding, convolutional encoding, or turbo encoding.

[0202] (Modulation section) The modulation unit 2073 modulates the encoded bits input from the encoding unit 2071 using a predetermined modulation scheme such as BPSK, π / 2BPSK, QPSK, 16QAM, 64QAM, or 256QAM.

[0203] (Uplink reference signal generation unit) The uplink reference signal generation unit 2079 generates an uplink reference signal based on RRC parameters set in the terminal device 50.

[0204] (Multiple part) The multiplexing unit 2075 multiplexes the modulation symbols and uplink reference signals for each channel and places them in a predetermined resource element.

[0205] (Wireless transmission unit) The wireless transmitter 2077 performs the following operations on the signal from the multiplexer 2075: conversion to a time-domain signal using an inverse fast Fourier transform, addition of a guard interval, generation of a baseband digital signal, conversion to an analog signal, and quadrature modulation. The wireless transmitter 2077 generates a transmission signal by performing processes such as conversion from an intermediate frequency signal to a high-frequency signal (upconversion), removal of extraneous frequency components, and power amplification. The transmission signal output by the wireless transmitter 2077 is transmitted from the transmitting and receiving antenna 209.

[0206] <<3. Example of communication system processing>> <3-1. Communication Processing Example> Figure 19 is a sequence diagram showing the flow of communication processing for downlink communication according to an embodiment of this disclosure. The communication processing shown in Figure 19 is performed by the communication system SYS1, for example, when a downlink signal to which a single-carrier modulation scheme is applied is transmitted by the communication system SYS1.

[0207] As shown in Figure 19, the base station 20 applies a first resource mapping to multiple signals and maps these multiple signals to time resources or logical resources for multiplexing (step S201).

[0208] The base station 20 performs DFT processing (or FFT processing) on ​​multiple signals mapped to time resources or logic resources to generate a DFT signal (an example of a first converted signal) (step S202).

[0209] The base station 20 applies a second resource mapping to the DFT signal, mapping the DFT signal to frequency resources and time resources (step S203).

[0210] The base station 20 performs IFFT processing on the DFT signal mapped to frequency resources and time resources to generate an IFFT signal (an example of a second converted signal) (step S204).

[0211] The base station 20 transmits control information, including mapping information for the first resource mapping and the second resource mapping, to the terminal device 50 (step S205). The base station 20 transmits the mapping information using, for example, DCI.

[0212] The base station 20 generates a downlink signal from the IFFT signal and transmits this downlink signal to the terminal device 50 (step S206).

[0213] The terminal device 50 decodes the received downlink signal (step S207).

[0214] <3-2. Signal Processing Examples> Figure 20 is a diagram showing an example of signal processing for downlink communication according to an embodiment of this disclosure. Figure 20 shows an example of signal processing when a single-carrier signal is transmitted as a downlink signal from base station 20 to terminal device 50.

[0215] This section illustrates the signal processing when base station 20 performs a first resource mapping on multiple signals. The signal processing when there is only one signal to be transmitted, or when the first resource mapping is not performed, is the same as in Figure 1, and therefore is omitted from this explanation.

[0216] As shown in Figure 20, error correction parity bits are added to the transmitted signal sequence using error correction coding (Channel coding). Subsequently, rate matching extracts a number of bits from the transmitted signal sequence according to the transmission resources and modulation scheme. Interleaving and scrambling are then applied to the extracted bits.

[0217] Next, the bit sequence is mapped to complex signal points through a modulation process. If transmission occurs across multiple layers, the bit sequence is mapped to complex signal points in each layer. In this process, for example, multiple signals are generated.

[0218] In this embodiment, a first resource mapping is performed, as shown in Figure 20.

[0219] Next, a Discrete Fourier Transformation (DFT) process called Transform precoding is performed on the signal that has undergone the first resource mapping. Note that this process, i.e., the DFT process performed here, may be called by a name other than Transform precoding. Also, in OFDM transmission, this Transform precoding process is omitted.

[0220] Subsequently, transmission weights are applied through pre-coding, a second resource mapping is performed, and then OFDM processing converts the frequency-domain transmission signal into a time-domain transmission signal (time-axis signal) for transmission. Since the process in Figure 20 is downlink communication, the time-domain transmission signal is transmitted from the base station 20 to the terminal device 50.

[0221] Note that in this case, pre-coding is performed before the second resource mapping, but pre-coding may also be performed after the second resource mapping, or pre-coding may be omitted altogether.

[0222] On the receiving end, the time-domain received signal is first converted into a frequency-domain signal (frequency-axis signal) by OFDM processing. After that, a second resource demapping is performed, followed by frequency equalization (Equalizer) processing to compensate for distortion caused by radio wave propagation.

[0223] An Inverse Discrete Fourier Transformation (IDFT) process, also known as Transform de-precoding, is performed. Next, the first resource demapping process takes place.

[0224] Subsequently, the signal mapped to multiple layers is returned, and soft determination is performed on each bit from the complex signal points. De-scrambling, de-interleave, de-rate matching, and error correction decoding (channel decoding) are performed on the bit values ​​obtained by this soft determination to obtain the received signal sequence.

[0225] <<4. Examples of signal multiplexing>> The following describes an example of multiplexing specific signals. The signals mentioned here are just examples, and other signals may be multiplexed according to this technique.

[0226] Furthermore, as described above, in this embodiment, the base station 20 performs a first resource mapping, mapping multiple signals to time resources or logical resources.

[0227] The time resources referred to here are not absolute time resources, but rather resources expressed in terms of relative time of signals, such as whether a signal is sent earlier or later.

[0228] A logical resource may be defined, for example, as a value ranging from 0 to (the maximum value of this predetermined size minus 1) within a given size. For example, this predetermined size may be defined by any of the following: Alternatively, the predetermined size may be defined by a different size (value), but is not limited to these. -Bandwidth Part - Component Carrier bandwidth -FFT size - Size notified in advance by base station 20 -Size determined statically in specifications, etc.

[0229] A logical resource may be referred to by another name. For example, a logical resource may be called a logical resource, virtual resource, virtual resource block, virtual resource block, virtual resource block, virtual resource block, etc. Alternatively, a logical resource may be referred to by any other name.

[0230] <4-1. Example of signal multiplexing across multiple physical channels> This section describes an example where base station 20 multiplexes signals transmitted on multiple different physical channels.

[0231] <4-1-1. Synchronization signals and / or system information> Here, we show an example where the base station 20 multiplexes a signal corresponding to at least one of a synchronization signal, system information, and a reference signal.

[0232] (Multiple synchronization signals) Figure 21 is a diagram showing an example of multiplexing of a synchronization signal according to an embodiment of the present disclosure. Figure 21 shows the process from when the base station 20 performs a first resource mapping and maps the signal to a time or logical resource, to when it performs IFFT processing.

[0233] Figure 21 shows an example where PSS and SSS are multiplexed as synchronization signals, but the multiplexed synchronization signals are not limited to PSS and SSS. For example, the synchronization signals may be synchronized signals to which a modulation scheme that can reduce PAPR (e.g., low-order modulation) is applied, and which are arranged in a continuous sequence.

[0234] The base station 20 resources-maps the PSS and SSS to time or logical resources (time resources or logical resources) (corresponding to the first resource mapping). Next, the base station 20 applies DFT processing (e.g., Transform precoding) to the mapped PSS and SSS together to generate a DFT signal that includes the PSS and SSS.

[0235] The base station 20 maps this DFT signal (PSS / SSS) to frequency and time resources (corresponding to a second resource mapping). The base station 20 applies IFFT processing (e.g., OFDM baseband signal generation) to the mapped DFT signal to generate an IFFT signal (OFDM baseband signal) that includes PSS and SSS.

[0236] The base station 20 processes the IFFT signal to generate a downlink signal (wireless signal) and transmits it to the terminal device 50.

[0237] In this example, the base station 20 multiplexes two synchronization signals (e.g., PSS and SSS), but the number of multiplexed synchronization signals is not limited to two. The base station 20 may multiplex three or more synchronization signals.

[0238] In this way, the base station 20 can reduce the PAPR while reducing the number of times DFT processing is applied by applying DFT processing to multiple synchronization signals together (multiplexed).

[0239] (Synchronization signals and system information) Figure 22 is a diagram showing an example of multiplexing of synchronization signals and system information according to an embodiment of this disclosure. Figure 22 shows the process from when the base station 20 performs a first resource mapping and maps the signals to time or logical resources, to when it executes IFFT processing.

[0240] Figure 22 shows an example in which PSS and SSS are multiplexed as synchronization signals, and information transmitted via PBCH is multiplexed as system information. Note that the multiplexed synchronization signals are not limited to PSS and SSS. For example, the synchronization signals may be synchronized signals that employ a modulation scheme that can reduce PAPR (e.g., low-order modulation) and are arranged in a continuous sequence.

[0241] The base station 20 resources-maps the PSS, SSS, and system information (PBCH) to time or logical resources (time resources or logical resources) (corresponding to the first resource mapping). Next, the base station 20 applies DFT processing (e.g., Transform precoding) to the mapped PSS, SSS, and system information to generate a DFT signal that includes the PSS, SSS, and system information.

[0242] The base station 20 maps this DFT signal (PSS / SSS / PBCH) to frequency and time resources (corresponding to a second resource mapping). The base station 20 applies IFFT processing (e.g., OFDM baseband signal generation) to the mapped DFT signal to generate an IFFT signal (OFDM baseband signal) that includes PSS, SSS, and system information (PBCH).

[0243] The base station 20 processes the IFFT signal to generate a downlink signal (wireless signal) and transmits it to the terminal device 50.

[0244] Here, an example where the base station 20 multiplexes two synchronization signals (e.g., PSS and SSS) is shown, but the number of multiplexed synchronization signals is not limited to two. The base station 20 may multiplex three or more synchronization signals. Also, in addition to or instead of the synchronization signals, the base station 20 may multiplex a plurality of system information.

[0245] In this way, the base station 20 can reduce the number of times the DFT process is applied while reducing the PAPR by collectively (multiplexing) applying the DFT process to a plurality of synchronization signals and system information.

[0246] (System Information and Reference Signal) FIG. 23 is a diagram showing an example of multiplexing system information and reference signals according to an embodiment of the present disclosure. In FIG. 23, the processing from when the base station 20 performs the first resource mapping and maps the signal to a time or logical resource until the IFFT process is executed is shown.

[0247] FIG. 23 shows an example in which information transmitted by PBCH as system information and a signal (e.g., DMRS) used for decoding the system information as a reference signal are multiplexed. Note that the multiplexed system information is not limited to the information transmitted by PBCH. Also, the reference signal is not limited to the signal used for decoding the system information.

[0248] The base station 20 performs resource mapping (corresponding to the first resource mapping) of the system information (PBCH) and the reference signal (DMRS) to a time or logical resource (time resource or logical resource). Next, the base station 20 collectively applies the DFT process (e.g., Transform precoding) to the mapped system information and reference signal to generate a DFT signal including the system information and the reference signal.

[0249] The base station 20 maps this DFT signal (PBCH / DMRS) to frequency and time resources (corresponding to the second resource mapping). The base station 20 applies IFFT processing (e.g., OFDM baseband signal generation) to the mapped DFT signal to generate an IFFT signal (OFDM baseband signal) including system information (PBCH) and reference signals (DMRS).

[0250] The base station 20 performs transmission signal processing on the IFFT signal, generates a downlink signal (radio signal), and transmits it to the terminal device 50.

[0251] Here, the number of system information multiplexed by the base station 20 is two (e.g., two PBCHs), but the number of multiplexed system information is not limited to two. The base station 20 may multiplex one system information and a reference signal, or may multiplex three or more system information with the reference signal.

[0252] Also, here, the number of reference signals multiplexed by the base station 20 is three (e.g., three DMRSs), but the number of multiplexed reference signals is not limited to three. The base station 20 may multiplex two or fewer reference signals and system information, or may multiplex four or more reference signals with system information.

[0253] In this way, the base station 20 can reduce the PAPR by applying DFT processing to the system information and reference signals together (multiplexing).

[0254] (Synchronization signal, system information, and reference signal) FIG. 24 is a diagram showing a multiplexing example of a synchronization signal, system information, and reference signal according to an embodiment of the present disclosure. In FIG. 24, the processing from when the base station 20 performs the first resource mapping and maps the signal to time or logical resources until the IFFT processing is executed is shown.

[0255] Here, an example is shown in which PSS and SSS are multiplexed as synchronization signals, but the multiplexed synchronization signals are not limited to PSS and SSS. For example, the synchronization signals may be synchronized signals to which a modulation scheme that can reduce PAPR (e.g., low-order modulation) is applied, and which are arranged in a continuous sequence.

[0256] Furthermore, this section shows an example where information transmitted via PBCH is multiplexed as system information. Note that the multiplexed system information is not limited to information transmitted via PBCH.

[0257] Furthermore, this example shows that a signal used for decoding system information (e.g., DMRS) is multiplexed as a reference signal. Note that the reference signal is not limited to a signal used for decoding system information.

[0258] The base station 20 maps multiple synchronization signals (PSS, SSS), system information (PBCH), and reference signals (DMRS) to time or logical resources (time resources or logical resources) (corresponding to the first resource mapping).

[0259] Next, the base station 20 applies DFT processing (e.g., Transform precoding) to the mapped synchronization signals, system information, and reference signals to generate a DFT signal that includes the system information and reference signals.

[0260] The base station 20 maps this DFT signal (PSS / SSS / PBCH / DMRS) to frequency and time resources (corresponding to a second resource mapping). The base station 20 applies IFFT processing (e.g., OFDM baseband signal generation) to the mapped DFT signal to generate an IFFT signal (OFDM baseband signal) that includes PSS, SSS, system information (PBCH), and reference signal (DMRS).

[0261] The base station 20 processes the IFFT signal to generate a downlink signal (wireless signal) and transmits it to the terminal device 50.

[0262] In this example, the number of synchronization signals that the base station 20 multiplexes is assumed to be two (for example, PSS and SSS), but the number of synchronization signals to be multiplexed is not limited to two. The base station 20 may multiplex one synchronization signal with system information and / or reference signals, or it may multiplex three or more synchronization signals with these.

[0263] Furthermore, although the number of system information items that the base station 20 multiplexes is assumed to be two (for example, two PBCHs), the number of system information items to be multiplexed is not limited to two. The base station 20 may multiplex one system information item with a synchronization signal and / or a reference signal, and may multiplex three or more system information items with these.

[0264] Furthermore, although the number of reference signals multiplexed by the base station 20 is assumed to be three (for example, three DMRS signals) here, the number of reference signals to be multiplexed is not limited to three. The base station 20 may multiplex two or fewer reference signals with synchronization signals and / or system information, or it may multiplex four or more reference signals with these.

[0265] In this way, the base station 20 can reduce the PAPR while reducing the number of times DFT processing is applied by applying DFT processing to the synchronization signal, system information, and reference signal together (multiplexed).

[0266] (Signal splitting) Figures 25 and 26 show other examples of multiplexing of synchronization signals and system information according to the embodiments of this disclosure. Figure 25 shows the process from when the base station 20 performs a first resource mapping, mapping the signal to a time or logical resource, to when it performs DFT processing. Figure 26 shows the process from when the base station 20 performs a second resource mapping after DFT processing, mapping the signal to a time or logical resource, to when it performs IFFT processing.

[0267] As shown in FIG. 25, the base station 20 divides the signal subjected to the first resource mapping. Here, the base station 20 divides the signals of PSS, SSS, and PBCH into two (first and second divided signals) by SSS.

[0268] Therefore, the first divided signal includes a part of PSS and SSS. Also, the second divided signal includes a part of SSS and PBCH.

[0269] The base station 20 performs DFT processing on the first divided signal to generate a first DFT signal. Also, the base station 20 performs DFT processing on the second divided signal to generate a second DFT signal.

[0270] Next, the base station 20 maps the first DFT signal (PSS / SSS) and the second DFT signal (PSS / PBCH) to frequency and time resources (corresponding to the second resource mapping). Here, the base station 20 maps the first and second DFT signals in the order of the first DFT signal and the second DFT signal on the time axis.

[0271] The base station 20 applies IFFT processing (for example, OFDM baseband signal generation) to the mapped first and second DFT signals to generate an IFFT signal (OFDM baseband signal) including PSS, SSS, and system information (PBCH).

[0272] Note that here, the case where the base station 20 divides the signal multiplexing the synchronization signal and the system information into two has been shown, but the signal divided by the base station 20 is not limited to this. For example, the base station 20 may divide various signals such as the signal multiplexing the above-described synchronization signal, the signal multiplexing the system information and the reference signal, etc. Alternatively, the base station 20 may divide a plurality of signals to which one resource mapping described later is applied in the same manner.

[0273] Furthermore, the number of signal divisions performed by the base station 20 is not limited to two, but may be three or more. Also, the signal division positions are not limited to the example in Figure 25. For example, the base station 20 can divide the signal at any position, such as dividing it so that the first divided signal includes PSS and SSS and the second divided signal includes PBCH.

[0274] In this way, the base station 20 can prevent the frequency bandwidth from becoming too wide when the second resource mapping is performed by dividing the multiple signals to which the first resource mapping is applied. In other words, the base station 20 can limit the frequency bandwidth of the downlink signal.

[0275] <4-1-2. Control signals and reference signals> This section shows an example where the base station 20 multiplexes control signals and reference signals.

[0276] Figure 27 shows an example of multiplexing of control signals and reference signals according to the embodiment of this disclosure. Figure 27 shows the process from when the base station 20 performs a first resource mapping and maps the signals to time or logical resources, to when it performs IFFT processing.

[0277] Figure 27 shows an example where the signal transmitted by PDCCH is multiplexed as a control signal, and DMRS is multiplexed as a reference signal. It also shows an example where control signals addressed to the first to third UE50s are multiplexed.

[0278] Note that the control signals (PDCCH) and reference signals (DMRS) shown herein are examples only and are not limited thereto. For example, the control signals may be signals addressed to two or fewer UE50s, or signals addressed to four or more UE50s.

[0279] As shown in Figure 27, the base station 20 resources-maps the control signal (PDCCH) and the reference signal (DMRS) to time or logical resources (corresponding to the first resource mapping).

[0280] At this time, the base station 20 may arrange the signals after resource mapping continuously on time or logical resources. By arranging the signals continuously on time or logical resources in this way, the base station 20 can prevent an increase in PAPR.

[0281] Next, the base station 20 applies DFT processing (e.g., Transform precoding) to the mapped control signals (PDCCH) and reference signals (DMRS) to generate a DFT signal that includes the control signals and reference signals.

[0282] Base station 20 receives the DFT signal (Figure 27, "Transform precoded PDCCH + DMRS for 1 st to 3 rd Map the UE (User Environment) to frequency and time resources (equivalent to a second resource mapping).

[0283] In this case, the base station 20 may arrange control signals and / or reference signals, which are mapped to time and frequency resources, continuously on the frequency axis. By arranging control signals and / or reference signals continuously on the frequency axis, the base station 20 can prevent an increase in PAPR.

[0284] The base station 20 applies IFFT processing (e.g., OFDM baseband signal generation) to the mapped DFT signal to generate an IFFT signal (OFDM baseband signal) that includes control signals and reference signals.

[0285] The base station 20 processes the IFFT signal to generate a downlink signal (wireless signal) and transmits it to the terminal device 50.

[0286] Here, for example, a control signal transmission resource set may be defined in the first resource mapping. For example, a resource area for control signals to be used for each terminal device 50 may be defined as a control signal resource set used in the first resource mapping.

[0287] For example, one or more resource sets may be defined for each terminal device 50 as a control resource set for the first resource mapping (e.g., 1st CORESET).

[0288] In this case, if DFT processing is not performed (in the case of a multi-carrier modulation scheme), the control signal resource set used in the first resource mapping does not need to be defined for each terminal device 50. In this case, for example, a control signal resource set used in the second resource mapping (e.g., 2nd CORESET) may be defined.

[0289] For example, one or more common resource sets (Common 1st CORESET) common to the terminal device 50 may be defined as a control signal resource set for the first resource mapping (e.g., CORESET for 1st).

[0290] In this case, if DFT processing is not performed (in the case of multi-carrier modulation), a control signal resource set used in the first resource mapping that is common to the terminal device 50 does not need to be defined. In this case, for example, a control signal resource set common to the terminal device 50 used in the second resource mapping (Common Control resource set for 2nd resource mapping: Common 2nd CORESET, etc.) may be defined.

[0291] For example, the 1st CORESET used in the first resource mapping may include one or more control signal search spaces.

[0292] The terminal device 50 attempts to decode the control signals contained in this search space. This search space may be defined as a UE-Specific Search Space specific to the terminal device 50. Alternatively, this search space may be defined as a Common Search Space common to all terminal devices 50.

[0293] (Omission of interleaving process) In this case, when applying a single-carrier modulation scheme to downlink communication, the base station 20 may perform a second resource mapping on the control signal and / or reference signal without applying interleaving.

[0294] Figure 28 shows an example of CCE-to-REG mapping with interleaving applied. The base station 20 applies interleaving to a resource element group (REG), for example, and assigns it to a control channel element (CCE) that constitutes a CORESET.

[0295] Here, because base station 20 applies interleaving, consecutive REGs are placed on different elements within the CORESET.

[0296] Figure 29 shows an example of CCE-to-REG mapping without interleaving. Base station 20 assigns, for example, a resource element group (REG) to a control channel element (CCE) that constitutes a CORESET without applying interleaving to the REG.

[0297] In this case, since base station 20 does not apply interleaving, consecutive REGs are not rearranged within the CORESET and remain in a consecutive position.

[0298] In this embodiment, it is assumed that the base station 20 performs downlink communication according to a single-carrier modulation scheme (e.g., DFT-S-OFDM) that applies DFT processing (e.g., Transform precoding).

[0299] In this case, DFT processing can achieve an effect equivalent to mapping the signal across the entire frequency domain. Therefore, applying interleaving to the control signal and / or reference signal by the base station 20 may not necessarily yield sufficient results.

[0300] Therefore, in this embodiment, the base station 20 may perform the second resource mapping without applying interleaving to the control signal and / or reference signal. This reduces the signal processing that the base station 20 performs, and a reduction in processing delay can be expected.

[0301] In this example, it is assumed that base station 20 does not apply interleaving to control signals and / or reference signals, but the signals to which interleaving is not applied are not limited to these. Base station 20 may also perform the second resource mapping without applying interleaving to signals other than control signals and / or reference signals.

[0302] <4-1-3. Data Signals and Reference Signals> This section shows an example where the base station 20 multiplexes the data signal and the reference signal.

[0303] Figure 30 shows an example of multiplexing of data signals and reference signals according to an embodiment of the present disclosure. Figure 30 shows the process from when the base station 20 performs a first resource mapping and maps the signals to time or logical resources, to when it performs IFFT processing.

[0304] Figure 30 shows an example where the signal transmitted by the PDSCH is multiplexed as a data signal, and the DMRS is multiplexed as a reference signal. It also shows an example where control signals addressed to the first to third UE50s are multiplexed.

[0305] Note that the data signal (PDSCH) and reference signal (DMRS) shown herein are examples only and are not limited thereto. For example, the data signal may be a signal addressed to two or fewer UE50s, or it may be a signal addressed to four or more UE50s.

[0306] As shown in Figure 30, the base station 20 resources-maps the data signal (PDSCH) and the reference signal (DMRS) to time or logical resources (corresponding to the first resource mapping).

[0307] At this time, the base station 20 may arrange the signals after resource mapping continuously on time or logical resources. By arranging the signals continuously on time or logical resources in this way, the base station 20 can prevent an increase in PAPR.

[0308] Next, the base station 20 applies DFT processing (e.g., Transform precoding) to the mapped data signal (PDSCH) and reference signal (DMRS) together to generate a DFT signal that includes the data signal and the reference signal.

[0309] Base station 20 receives the DFT signal (Figure 30, "Transform precoded PDSCH + DMRS for 1 st to 3 rd Map the UE (User Environment) to frequency and time resources (equivalent to a second resource mapping).

[0310] In this case, the base station 20 may arrange the data signals and / or reference signals, which are mapped to time and frequency resources, continuously on the frequency axis. By arranging the data signals and / or reference signals continuously on the frequency axis, the base station 20 can prevent an increase in PAPR.

[0311] The base station 20 applies IFFT processing (e.g., OFDM baseband signal generation) to the mapped DFT signal to generate an IFFT signal (OFDM baseband signal) that includes a data signal and a reference signal.

[0312] The base station 20 processes the IFFT signal to generate a downlink signal (wireless signal) and transmits it to the terminal device 50.

[0313] Figure 31 shows another example of multiplexing of data signals and reference signals according to the embodiments of this disclosure. Here, it is the same as in Figure 30 except that the base station 20 multiplexes a Channel State Information Reference Signal (CSI-RS) in addition to DMRS as a reference signal.

[0314] Thus, the multiplexed reference signal is not limited to DMRS; it may be CSI-RS or any other reference signal.

[0315] <4-1-4. Reference signal> Here, we show an example where base station 20 multiplexes multiple different reference signals.

[0316] Figure 32 shows an example of multiplexing of a reference signal according to an embodiment of the present disclosure. Figure 32 shows the process from when the base station 20 performs a first resource mapping and maps the signal to a time or logical resource, to when it performs IFFT processing.

[0317] Figure 32 shows an example where reference signal #1, reference signal #2, and reference signal #3 are multiplexed together as reference signals.

[0318] Note that reference signals #1 to #3 are just examples and are not limited to them. For example, the number of reference signals may be two or fewer, or four or more. For example, reference signals #1 to #4 may be multiplexed.

[0319] As shown in Figure 32, the base station 20 resources-maps the reference signals (reference signals #1 to #3) to time or logical resources (corresponding to the first resource mapping). At this time, the base station 20 may arrange the resource-mapped signals continuously on the time or logical resources. By arranging the reference signals continuously on the time or logical resources in this way, the base station 20 can prevent an increase in PAPR.

[0320] Next, the base station 20 applies DFT processing (e.g., Transform precoding) to the mapped reference signals (reference signals #1 to #3) to generate a DFT signal that includes the reference signals.

[0321] Base station 20 maps the DFT signal ("Transform precoded multiple Reference Signals" in Figure 32) to frequency and time resources (corresponding to the second resource mapping).

[0322] In this case, the base station 20 may arrange the reference signals, which are mapped to time and frequency resources, continuously on the frequency axis. By arranging the reference signals continuously on the frequency axis, the base station 20 can prevent an increase in PAPR.

[0323] The base station 20 applies IFFT processing (e.g., OFDM baseband signal generation) to the mapped DFT signal to generate an IFFT signal (OFDM baseband signal) that includes a reference signal.

[0324] The base station 20 processes the IFFT signal to generate a downlink signal (wireless signal) and transmits it to the terminal device 50.

[0325] Examples of reference signals include the following signals. Note that these are just examples, and other reference signals may be multiplexed. -CSI-RS -DMRS -Phase Tracking Reference Signal (PT-RS) -Tracking Reference Signal (TRS) -Positioning Reference Signal (PRS) -CSI Interference Measurement(CSI-IM)

[0326] Here, for example, a reference signal group resource may be defined in the first resource mapping. For example, the terminal device 50 may use the reference signal group resource (reference signal transmission group resource) to perform processing using the reference signal, such as estimating the channel state.

[0327] The reference signal group resource may be used for transmission to one terminal device 50, or it may be used for transmission to multiple terminal devices 50.

[0328] For example, a resource area for the reference signal to be used for each terminal device 50 may be defined within the reference signal group resources.

[0329] For example, one or more resource sets may be defined for each terminal device 50 as a Reference signal resource set (RSRESET, etc.).

[0330] Figure 33 shows an example of a resource set according to the embodiment of this disclosure. In Figure 33, RSRESET #0 defines a resource area from the fourth reference signal #1 to the seventh reference signal #1 from the beginning. Also, RSRESET #1 defines a resource area from the first reference signal #1 to the sixth reference signal #3 from the beginning.

[0331] The reference signal group resource may be set specifically for the terminal device 50, or it may be set in common for the terminal devices 50.

[0332] <4-2. Example of setting up the first resource mapping> The following describes an example of the settings, etc., when the first resource mapping is performed.

[0333] (Continuity of multiplexed signals) Multiple different signals multiplexed by the base station 20 may be resource-mapped contiguously on a time or logical resource. Alternatively, multiple different signals multiplexed by the base station 20 may be resource-mapped discontinuously on a time or logical resource.

[0334] (Maximum number of resources) The maximum number of resources in the first resource mapping may be calculated from the following values, etc. - Bandwidth of the configured component carrier - Bandwidth of the configured Band Width Part (BWP) - The size of the set discrete Fourier transform - The size of the set Fast Fourier Transform

[0335] (Resource-related information) For each terminal device 50, one or more pieces of information (resource-related information) relating to the limitation of the resources to which the first resource mapping applies may be set.

[0336] The information to be set may include at least one of the following: -Starting point of the first resource mapping - Resource width of the first resource mapping - Signal point bundle information, which is a bundle of multiple signal point information used in the first resource mapping. - Interleaving information applied in the first resource mapping - Information regarding the range of control information transmission resources transmitted in the first resource mapping.

[0337] Note that the information listed here is just an example, and other information may be set as resource-related information for each terminal device 50.

[0338] Resource-related information may be configured, for example, in DCI. Alternatively, resource-related information may be configured in MAC CE. Resource-related information may be configured in RRC Signaling. Resource-related information may also be defined as static information in standards, etc.

[0339] By setting resource-related information, the terminal device 50 can search for received signals only for resources set based on this information. This allows the terminal device 50 to reduce the amount of processing required to search for received signals.

[0340] (Signaling) The base station 20 notifies the terminal device 50, for example, of information regarding the first resource mapping (mapping information). This notification may be dynamically sent via DCI or the like.

[0341] The notified mapping information may include at least one of the following: - Start position of the transmission resource - Number of resources sent - End position of the sending resource - Whether or not interleaving is applied

[0342] The base station 20 may, for example, notify the terminal device 50 of information regarding the method of transmitting the reference signal (reference information). For example, the reference information may include information indicating whether the transmitted reference signal is a reference signal specific to the terminal device 50 or a reference signal common to the terminal devices 50.

[0343] (Processing order) In the signal processing described above, base station 20 performed DFT processing after performing the first resource mapping. However, the order of processing performed by base station 20 is not limited to this.

[0344] For example, the base station 20 may perform the first resource mapping immediately before the DFT processing, or it may perform the first resource mapping even earlier than immediately before the DFT processing.

[0345] For example, base station 20 may perform a first resource mapping before antenna port mapping (e.g., immediately before). For example, base station 20 may perform a first resource mapping before layer mapping (e.g., immediately before).

[0346] For example, base station 20 may perform a first resource mapping before Modulation (e.g., immediately before). For example, base station 20 may perform a first resource mapping before Scrambling (e.g., immediately before).

[0347] (others) For example, base station 20 may perform downlink communication by applying signal multiplexing using the first resource mapping in cells where BWP is not applied, and perform downlink communication without applying the first resource mapping in cells where BWP is applied.

[0348] For example, base station 20 may perform downlink communication by applying signal multiplexing using the first resource mapping when the set frequency bandwidth is the same as that of the Component Carrier (CC). Base station 20 may perform downlink communication without applying the first resource mapping when the set frequency bandwidth is not the same as that of the Component Carrier (CC), i.e., when they are different.

[0349] For example, base station 20 may perform downlink communication in a Secondary cell (SCell) by applying signal multiplexing using the first resource mapping. Base station 20 may also perform downlink communication in a cell other than an SCell, such as a Primary Cell (PCell), without applying the first resource mapping.

[0350] For example, base station 20 may perform downlink communication by applying signal multiplexing using the first resource mapping in the SCG PSCell of the Secondary Cell Group (SCG). Base station 20 may also perform downlink communication without applying the first resource mapping in a device other than the SCG PSCell.

[0351] For example, base station 20 may perform downlink communication by applying signal multiplexing using the first resource mapping in the SCG SCell of a Secondary Cell Group (SCG). Base station 20 may also perform downlink communication without applying the first resource mapping in a location other than the SCG SCell.

[0352] When performing downlink communication with the first resource mapping applied, the base station 20 may use the same DFT size as the IFFT size for the DFT processing (e.g., Transform precoding) performed after the first resource mapping. The IFFT size is used for the IFFT processing performed after the DFT processing.

[0353] <<5. Example of signal reception processing>> The following describes an example of the downlink signal reception processing by the terminal device 50 according to this embodiment.

[0354] <5-1. Synchronization signals and / or system information> Figures 34 and 35 show an example of the downlink signal reception process according to the embodiment of this disclosure. Figure 34 shows the process up to the point in which the base station 20 performs IDFT processing on the received signal. Figure 35 shows the process up to the point in which the base station 20 performs first resource demapping and obtains each signal.

[0355] Here, terminal device 50 receives a downlink signal which is multiplexed with multiple synchronization signals (e.g., PSS and SSS), system information (e.g., information transmitted by PBCH), and reference information (e.g., DMRS).

[0356] The terminal device 50 performs FFT processing (for example, OFDM baseband signal generation) on the received signal to generate an FFT signal (OFDM baseband signal), which is a frequency-time domain signal.

[0357] The terminal device 50 performs demapping (corresponding to the second resource demapping) to extract the signals of the resources subject to IDFT processing (IDFT resources) (hereinafter also referred to as IDFT target signals) from the FFT signal, based on information about a second resource mapping that has been notified in advance or is implicitly determined (this corresponds to the second resource demapping).

[0358] The terminal device 50 performs IDFT processing (Transform precoding) on ​​the IDFT target signal to obtain an IDFT signal. The terminal device 50 may perform IFFT processing instead of IDFT processing.

[0359] The terminal device 50 performs demapping to extract synchronization signals (PSS / SSS) and system information (including PBCH and DMRS) from the IDFT signal (first resource demapping). At this time, the terminal device 50 may extract the resources from which signals are to be extracted based on information about the first resource mapping that has been notified in advance or has been statically determined.

[0360] The terminal device 50 performs processing according to the extracted signal. For example, the terminal device 50 correlates the received PSS with a candidate PSS signal sequence (Potential PSS sequence) and determines the PSS. For example, the terminal device 50 correlates the received SSS with a candidate SSS signal sequence (Potential SSS sequence) and determines the SSS.

[0361] The terminal device 50 performs channel estimation using a reference signal (in this case, DMRS) included in the PBCH. Based on the channel estimation result, the terminal device 50 performs subsequent decoding processing (e.g., De-mapper) to decode the system information transmitted by the PBCH.

[0362] In this explanation, the terminal device 50 receives PSS and / or SSS as synchronization signals, but the synchronization signals received by the terminal device 50 are not limited to PSS and / or SSS. For example, the synchronization signals may be synchronized signals to which a modulation scheme that can reduce PAPR (e.g., low-order modulation) is applied, and which are arranged in a continuous sequence.

[0363] Furthermore, while system information is defined here as information transmitted via PBCH, system information is not limited to information transmitted via PBCH. Also, while the reference signal is defined here as a signal used to decode system information (e.g., DMRS), the reference signal is not limited to a signal used to decode system information.

[0364] Furthermore, the received signal may include, for example, a synchronization signal, system information, and at least one of the reference signals. For example, if the terminal device 50 receives a received signal that includes system information and reference information, it will perform the same processing as shown in Figures 34 and 35.

[0365] <5-2. Control signals and reference signals> Figure 36 shows another example of the downlink signal reception processing according to the embodiment of this disclosure. Note that the processing up to the point in which the base station 20 performs IDFT processing on the received signal is the same as the processing shown in Figure 34, so the explanation is omitted here. Figure 36 shows the processing up to the point in which the base station 20 performs the first resource demapping and obtains each signal.

[0366] Here, the terminal device 50 receives a downlink signal which is multiplexed with control signals (e.g., signals transmitted via PDCCH) and reference information (e.g., DMRS).

[0367] The terminal device 50 performs demapping to extract control signals (PDCCH / DMRS) addressed to itself from the IDFT signal (first resource demapping). At this time, the terminal device 50 may extract the resources from which signals are to be extracted based on information about the first resource mapping that has been notified in advance or has been statically determined.

[0368] Terminal device 50 performs signal processing on control signals etc. addressed to itself. For example, the first terminal device 501 performs signal processing on PDCCH(PDCCH for 1) addressed to the first terminal device 501 extracted in the first resource mapping. st Signal processing is applied to the UE.

[0369] In this case, the first terminal device 501 may perform channel estimation using the DMRS transmitted using the resources of the first terminal device 501.

[0370] Alternatively, the first terminal device 501 may perform channel estimation using the DMRS included in the received signal (e.g., the IDFT signal). In other words, the first terminal device 501 may perform channel estimation using the DMRS transmitted using the resources of the first to third terminal devices 501 to 503.

[0371] By performing channel estimation using the DMRS contained in the received signal (e.g., the IDFT signal), the first terminal device 501 can further improve the accuracy of channel estimation.

[0372] The first terminal device 501 performs subsequent decoding processes (e.g., De-mapper) based on the channel estimation result to decode the control signals transmitted via PDCCH.

[0373] The second and third terminal devices 502 and 503 also decode control information, etc., that has been sent to them via PDCCH in the same manner.

[0374] <5-3. Data Signals and Reference Signals> Figure 37 shows another example of the downlink signal reception processing according to the embodiment of this disclosure. Note that the processing up to the point in which the base station 20 performs IDFT processing on the received signal is the same as the processing shown in Figure 34, so the explanation is omitted here. Figure 37 shows the processing up to the point in which the base station 20 performs the first resource demapping and obtains each signal.

[0375] Here, the terminal device 50 receives a downlink signal which is multiplexed with data signals (e.g., signals transmitted by PDSCH) and reference information (e.g., DMRS).

[0376] The terminal device 50 performs demapping to extract control signals (PDSCH / DMRS) addressed to itself from the IDFT signal (first resource demapping). At this time, the terminal device 50 may extract the resources from which signals are to be extracted based on information about the first resource mapping that has been notified in advance or has been statically determined.

[0377] Terminal device 50 performs signal processing on control signals etc. addressed to itself. For example, the first terminal device 501 receives PDCCH(PDSCH for 1) addressed to the first terminal device 501 extracted in the first resource mapping. st Signal processing is applied to the UE.

[0378] In this case, the first terminal device 501 may perform channel estimation using the DMRS transmitted using the resources of the first terminal device 501.

[0379] Alternatively, the first terminal device 501 may perform channel estimation using the DMRS included in the received signal (e.g., the IDFT signal). In other words, the first terminal device 501 may perform channel estimation using the DMRS transmitted using the resources of the first to third terminal devices 501 to 503.

[0380] By performing channel estimation using the DMRS contained in the received signal (e.g., the IDFT signal), the first terminal device 501 can further improve the accuracy of channel estimation.

[0381] The first terminal device 501 performs subsequent decoding processes (e.g., De-mapper) based on the channel estimation result to decode the data signal transmitted via PDSCH.

[0382] The second and third terminal devices 502 and 503 also decode control information, etc., that has been sent to them via PDCCH in the same manner.

[0383] In this example, DMRS is included as the reference signal, but CSI-RS may be included as the reference signal in addition to or instead of DMRS.

[0384] <5-4.Reference signal> Figure 38 shows another example of the downlink signal reception process according to the embodiment of this disclosure. Note that the process up to the point in which the base station 20 performs IDFT processing on the received signal is the same as the process shown in Figure 34, so the explanation is omitted here. Figure 38 shows the process up to the point in which the base station 20 performs the first resource demapping and obtains each signal.

[0385] Here, terminal device 50 receives a downlink signal in which multiple different reference signals are multiplexed.

[0386] The terminal device 50 performs demapping to extract a reference signal addressed to itself from the IDFT signal (first resource demapping). At this time, the terminal device 50 may extract the resources from which to extract signals based on information about the first resource mapping that has been notified in advance or has been statically determined.

[0387] Terminal device 50 performs subsequent signal processing on reference signals addressed to itself. For example, the first terminal device 501 performs subsequent signal processing on the first terminal device 501-addressed (e.g., reference signal #1) extracted in the first resource mapping.

[0388] The second and third terminal devices 502 and 503 similarly extract reference signals #2 and #3 addressed to themselves and perform subsequent signal processing.

[0389] <<6. Relationship between signal waveforms>> For example, the signal waveforms of the downlink and the uplink may have the following relationships:

[0390] For example, if a second signal waveform (single-carrier modulation scheme) is set for downlink communication, the second signal waveform will also be set for uplink communication.

[0391] In this case, the terminal device 50 assumes that the second signal waveform set in the downlink communication will also be set in the uplink communication. That is, if the second signal waveform is set in the downlink communication, the terminal device 50 assumes that the first signal waveform (multi-carrier modulation scheme) will not be set in the uplink communication.

[0392] For example, when considering coverage such as cell edges, it is assumed that a first signal waveform will be set on both the uplink and downlink links.

[0393] For example, if a first signal waveform is set for downlink communication, the first signal waveform will also be set for uplink communication.

[0394] In this case, the terminal device 50 assumes that the first signal waveform set in the downlink communication will also be set in the uplink communication. That is, if the first signal waveform is set in the downlink communication, the terminal device 50 assumes that the second signal waveform will not be set in the uplink communication.

[0395] Thus, for example, in coverage where communication using the first signal waveform is possible in downlink communication, it is assumed that communication using the first signal waveform will also be performed in uplink communication.

[0396] Alternatively, if a first signal waveform is set in downlink communication, then the first signal waveform and / or a second signal waveform are set in uplink communication.

[0397] In this case, the terminal device 50 assumes that if the first signal waveform is set in the downlink communication, then the first signal waveform and / or the second signal waveform will be set in the uplink communication.

[0398] For example, if a second signal waveform is set for uplink communication, the second signal waveform will also be set for downlink communication.

[0399] In this case, terminal device 50 assumes that the second signal waveform set in the uplink communication will also be set in the downlink communication. That is, if the second signal waveform is set in the uplink communication, terminal device 50 assumes that the first signal waveform will not be set in the downlink communication.

[0400] For example, when considering coverage such as cell edges, it is assumed that a first signal waveform will be set on both the uplink and downlink links.

[0401] For example, if a first signal waveform is set for uplink communication, the first signal waveform will also be set for downlink communication.

[0402] In this case, terminal device 50 assumes that the first signal waveform set in the uplink communication will also be set in the downlink communication. That is, if the first signal waveform is set in the uplink communication, terminal device 50 assumes that the second signal waveform will not be set in the downlink communication.

[0403] Thus, for example, in coverage where communication using the first signal waveform is possible in uplink communication, it is assumed that communication using the first signal waveform will also be performed in downlink communication.

[0404] Alternatively, if a first signal waveform is set in uplink communication, then the first signal waveform and / or a second signal waveform are set in downlink communication.

[0405] In this case, the terminal device 50 assumes that if the first signal waveform is set in the uplink communication, then the first signal waveform and / or the second signal waveform will be set in the downlink communication.

[0406] <<7. Signal Waveform Examples>> In the embodiments described above, the first signal waveform is CP-OFDM and the second signal waveform is DFT-S-OFDM, but the signal waveforms are not limited to these examples.

[0407] For example, the first signal waveform can be any signal waveform using a multi-carrier modulation scheme. Examples of multi-carrier modulation schemes include the following: -CP-OFDM with WOLA(Cyclic Prefix - Orthogonal Frequency Division Multiplexing with Weighted Overlap and Add) -UFMC(Universal Filter Multi Carrier) -FBMC(Filter-Bank Multi Carrier) -GFDM(Generalized Frequency Division Multiplexing)

[0408] For example, the second signal waveform can be any single-carrier modulation waveform. Examples of single-carrier modulation schemes include the following: -Constant envelope -SC-QAM(Single Carrier - Quadrature Amplitude Modulation) -SC-FDE(single-carrier modulation with frequency domain equalization) -SC-FDM(Single Carrier - Frequency Division Multiple) -Zero-tail SC-FDM

[0409] <<8. Other Embodiments>> The processing according to the above-described embodiment may be carried out in various other forms besides those described above.

[0410] In a dual connectivity environment, the terminal device 50 communicates with multiple base stations 20. In this case, the downlink signal waveform may be set for each of the multiple base stations 20 to which it is connected.

[0411] For example, suppose terminal device 50 is connected to base stations 20A and 20B via dual connectivity. In this case, terminal device 50 may use a second signal waveform for downlink communication with base station 20A and a first signal waveform for downlink communication with base station 20B.

[0412] Alternatively, the terminal device 50 may use the first signal waveform for both downlink communication with base station 20A and downlink communication with base station 20B. The terminal device 50 may use the second signal waveform for both downlink communication with base station 20A and downlink communication with base station 20B.

[0413] In a dual connectivity environment, the terminal device 50 may acquire information regarding the signal waveform used for downlink communication of the other base station 20 (e.g., base station 20B) from one base station 20 (e.g., base station 20A) (for example, corresponding to the second waveform information described above).

[0414] For example, terminal device 50 receives a downlink signal from the other base station 20 based on the acquired second waveform information.

[0415] Furthermore, for example, when a terminal device 50 is communicating with one base station 20 using both the first signal waveform and the second signal waveform, the communication using one of the signal waveforms may be switched from one base station 20 to the other base station 20.

[0416] For example, suppose that terminal device 50 is communicating with base station 20A using both the first signal waveform and the second signal waveform. In this case, terminal device 50 may switch the downlink communication using the first signal waveform from base station 20A to base station 20B depending on the quality of the downlink communication using the first signal waveform with base station 20A and / or base station 20B.

[0417] For example, if the quality of downlink communication using the first signal waveform with base station 20A falls below a threshold, base station 20A (or terminal device 50) decides to switch downlink communication using the first signal waveform from base station 20A to base station 20B.

[0418] Alternatively, for example, base station 20A (or terminal device 50) may decide to switch downlink communication using the first signal waveform from base station 20A to base station 20B if the quality of downlink communication using the first signal waveform with base station 20B exceeds a threshold.

[0419] For example, if the quality of downlink communication with base station 20A using the first signal waveform falls below the quality of downlink communication with base station 20B using the first signal by an offset or more, base station 20A (or terminal device 50) decides to switch from base station 20A to base station 20B.

[0420] For example, the control device that controls the base station 20 and terminal device 50 in each of the above embodiments may be implemented by a dedicated computer system or by a general-purpose computer system.

[0421] For example, a communication program for performing the above-described operations is stored in a computer-readable recording medium such as an optical disc, semiconductor memory, magnetic tape, or flexible disk and distributed. Then, for example, the control device is configured by installing the program on a computer and executing the above-described process. In this case, the control device may be an external device (e.g., a personal computer) of the base station 20 and terminal device 50. Alternatively, the control device may be an internal device (e.g., control units 103 and 203) of the base station 20 and terminal device 50.

[0422] Alternatively, the above communication program may be stored on a disk device provided by a server on a network such as the Internet, and made available for download to a computer. Furthermore, the above functions may be realized through the cooperation of an OS (Operating System) and application software. In this case, the parts other than the OS may be stored on a medium and distributed, or the parts other than the OS may be stored on a server device and made available for download to a computer.

[0423] Furthermore, among the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically by known methods. In addition, the processing procedures, specific names, and information including various data and parameters shown in the above document and drawings can be arbitrarily changed unless otherwise specified. For example, the various information shown in each figure is not limited to the information shown.

[0424] Furthermore, the components of each illustrated device are functionally conceptual and do not necessarily need to be physically configured as shown. In other words, the specific forms of distribution and integration of each device are not limited to those shown, and all or part of them can be functionally or physically distributed and integrated in any unit according to various loads and usage conditions.

[0425] Furthermore, the embodiments described above can be combined as appropriate, as long as the processing content is not contradictory.

[0426] Furthermore, the effects described herein are merely illustrative and not limiting; other effects may also occur.

[0427] Furthermore, the embodiment can also be implemented as any configuration constituting the device or system, such as a processor as a system LSI (Large Scale Integration), a module using multiple processors, a unit using multiple modules, or a set with additional functions added to a unit (i.e., a configuration of part of the device).

[0428] In this embodiment, a system refers to a collection of multiple components (devices, modules (parts), etc.), regardless of whether all components are located in the same enclosure. Therefore, multiple devices housed in separate enclosures and connected via a network, and a single device containing multiple modules within a single enclosure, are both considered systems.

[0429] Furthermore, for example, each embodiment can adopt a cloud computing configuration in which a single function is shared and processed collaboratively by multiple devices via a network.

[0430] <<9. Conclusion>> Although the embodiments of this disclosure have been described above, the technical scope of this disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the gist of this disclosure. Furthermore, components from different embodiments and modifications may be combined as appropriate.

[0431] Furthermore, the effects described in each embodiment of this specification are merely illustrative and not limiting, and other effects may also occur.

[0432] Furthermore, this technology can also be configured as follows. (1) Applying a first resource mapping to multiple signals, the multiple signals are mapped to time resources or logical resources. A Fourier transform is applied to the plurality of signals to which the first resource mapping has been applied to generate a first transformed signal. The second resource mapping is applied to the first converted signal to map the first converted signal to frequency resources and time resources. The first transformed signal to which the second resource mapping has been applied is subjected to an inverse Fourier transform to generate a second transformed signal. A downlink signal to which a single-carrier modulation scheme is applied is generated from the second converted signal. Base station. (2) The base station according to (1), wherein the plurality of signals include a plurality of synchronization signals. (3) The base station according to (1) or (2), wherein the plurality of signals include sequentially arranged synchronization signals. (4) The multiple signals include PSS and SSS, and are base stations as described in any one of (1) to (3). (5) The base station according to any one of (1) to (4), wherein the plurality of signals include system information and a reference signal used for decoding the system information. (6) The multiple signals include DMRS and PBCH signals, as described in any one of (1) to (5). (7) The base station according to (1), wherein the plurality of signals include a plurality of reference signals. (8) The base station according to (7), wherein the plurality of reference signals include the reference signals destined for a plurality of different terminal devices. (9) The base station according to (7) or (8), wherein the plurality of signals include one or more data signals. (10) The base station as described in (1), wherein each of the aforementioned signals is a signal from a different physical channel. (11) The base station described in (1), wherein the multiple signals are signals of one physical channel. (12) A base station according to any one of (1) to (11), which applies the first resource mapping to multiple signals using one or more resource sets defined for each terminal device. (13) One or more resource sets include one or more search spaces, as described in (12). (14) A base station according to any one of (1) to (11), which applies the first resource mapping to multiple signals using one or more resource sets defined in common to multiple terminal devices. (15) One or more resource sets include one or more search spaces, as described in (14). (16) A base station according to any one of (1) to (15), wherein the second resource mapping is applied to the first conversion signal without applying interleaving. (17) The multiple signals to which the first resource mapping has been applied are divided into multiple divided signals. A plurality of first converted signals are generated by applying the Fourier transform to each of the plurality of partitioned signals. The second resource mapping is applied to a plurality of the first converted signals to map the plurality of the first converted signals to frequency resources and time resources. The second transformed signal is generated by applying the inverse Fourier transform to a plurality of the first transformed signals to which the second resource mapping has been applied. A base station listed in any one of (1) to (16). (18) A base station according to any one of (1) to (17), which maps a plurality of the aforementioned signals sequentially on the time resource or the logical resource. (19) A base station according to any one of (1) to (18), which applies the first resource mapping to a plurality of the signals according to the maximum number of resources calculated according to at least one of the set component carrier bandwidth, the set BWP bandwidth, and the set size of the Fourier transform. (20) A base station according to any one of (1) to (19), which starts the first resource mapping from a point where the time resource or the logical resource is set. (twenty one) A base station according to any one of (1) to (20), which applies the first resource mapping within the configured resource width of the time resource or the logical resource. (twenty two) A base station according to any one of (1) to (21), which notifies the terminal device of mapping information relating to PSYA-R062965_SYP355940P01 in the first resource mapping. (twenty three) The base station according to (22), wherein the mapping information includes information relating to one of the following: the starting position of the transmission resources, the number of transmission resources, the ending position of the transmission resources, and whether or not interleaving is applied to the first conversion signal. (twenty four) A base station according to any one of (1) to (23) that generates the downlink signal in a cell to which BWP is not applied. (twenty five) A base station according to any one of (1) to (24), which generates the downlink signal when the set frequency bandwidth is the same as that of the component carrier. (26) Receiving a downlink signal to which single-carrier modulation is applied, A second transformed signal is generated by applying a Fourier transform to the aforementioned downlink signal. The second converted signal is then subjected to a second resource demapping to demap the second converted signal into frequency resources and time resources. The second transformed signal to which the second resource demapping has been applied is subjected to an inverse Fourier transform to generate the first transformed signal. Applying a first resource demapping to the first conversion signal, the first conversion signal is demmapped to a time resource or a logical resource. Multiple signals are generated from the first converted signal to which the first resource demapping has been applied. Terminal device. (27) The downlink signal is received from the base station. The aforementioned base station is Applying a first resource mapping to multiple signals, the multiple signals are mapped to time resources or logical resources. A Fourier transform is applied to the plurality of signals to which the first resource mapping has been applied to generate a first transformed signal. The second resource mapping is applied to the first converted signal to map the first converted signal to frequency resources and time resources. The first transformed signal to which the second resource mapping has been applied is subjected to an inverse Fourier transform to generate a second transformed signal. The downlink signal to which a single-carrier modulation scheme is applied is generated from the second converted signal. Terminal device. (28) Applying a first resource mapping to multiple signals to map multiple such signals to time resources or logical resources, A first transformed signal is generated by applying a Fourier transform to a plurality of signals to which the first resource mapping has been applied. Applying a second resource mapping to the first converted signal to map the first converted signal to frequency resources and time resources, The second transformed signal is generated by applying an inverse Fourier transform to the first transformed signal to which the second resource mapping has been applied, The process involves generating a downlink signal to which a single-carrier modulation scheme is applied from the second converted signal, A communication method that includes this. (29) Applying a Fourier transform to a downlink signal to which a single-carrier modulation scheme is applied generates a second transformed signal. Applying a second resource demapping to the second converted signal to demmap the second converted signal into frequency resources and time resources, The second transformed signal to which the second resource demapping has been applied is subjected to an inverse Fourier transform to generate the first transformed signal, Applying a first resource demapping to the first conversion signal to demmap the first conversion signal to a time resource or a logical resource, The process involves generating multiple signals from the first converted signal to which the first resource demapping has been applied, A communication method that includes this. (30) This includes receiving downlink signals from the base station, The aforementioned base station is Apply the first resource demapping to multiple signals to demmap multiple such signals to time resources or logical resources. A Fourier transform is applied to the plurality of signals to which the first resource demapping has been applied to generate a first transformed signal. The first converted signal is then subjected to a second resource demapping to demap the first converted signal into frequency resources and time resources. The first transformed signal to which the second resource demapping has been applied is subjected to an inverse Fourier transform to generate a second transformed signal. The downlink signal to which a single-carrier modulation scheme is applied is generated from the second converted signal. Communication method. [Explanation of Symbols]

[0433] 20 base station 50 Terminal devices 101,201 Upper Layer Processing Unit 103,203 Control Unit 105,205 Receiving section 107,207 Transmitter 109,209 Transmitting and Receiving Antennas

Claims

1. Applying a first resource mapping to multiple signals, the multiple signals are mapped to time resources or logical resources. A Fourier transform is applied to the plurality of signals to which the first resource mapping has been applied to generate a first transformed signal. The second resource mapping is applied to the first converted signal to map the first converted signal to frequency resources and time resources. The first transformed signal to which the second resource mapping has been applied is subjected to an inverse Fourier transform to generate a second transformed signal. A downlink signal to which a single-carrier modulation scheme is applied is generated from the second converted signal. Base station.

2. The base station according to claim 1, wherein the plurality of signals include a plurality of synchronization signals.

3. The base station according to claim 1, wherein the plurality of signals include system information and a reference signal used for decoding the system information.

4. The base station according to claim 1, wherein the plurality of signals include a plurality of reference signals.

5. The base station according to claim 4, wherein the plurality of signals include one or more data signals.

6. The base station according to claim 1, wherein each of the multiple signals is a signal from a different physical channel.

7. The base station according to claim 1, wherein the plurality of signals are signals of one physical channel.

8. The base station according to claim 1, wherein the first resource mapping is applied to a plurality of signals using one or more resource sets defined for each terminal device.

9. The base station according to claim 1, wherein the first resource mapping is applied to a plurality of signals using one or more resource sets defined in common to a plurality of terminal devices.

10. The base station according to claim 1, wherein the second resource mapping is applied to the first conversion signal without applying interleaving.

11. The base station according to claim 1, wherein a plurality of the signals are continuously mapped on the time resource or the logical resource.

12. The base station according to claim 1, wherein the first resource mapping is applied to a plurality of signals according to the maximum number of resources calculated according to at least one of the set component carrier bandwidth, the set BWP bandwidth, and the set size of the Fourier transform.

13. The base station according to claim 1, wherein the first resource mapping is initiated from a point where the time resource or the logical resource is set.

14. The base station according to claim 1, wherein the first resource mapping is applied to the configured resource width of the time resource or the logical resource.

15. The base station according to claim 1, which notifies a terminal device of mapping information relating to the first resource mapping.

16. The base station according to claim 1, which generates the downlink signal in a cell to which BWP is not applied.

17. The base station according to claim 1, which generates the downlink signal when the set frequency bandwidth is the same as that of the component carrier.

18. Receiving a downlink signal to which single-carrier modulation is applied, A second transformed signal is generated by applying a Fourier transform to the aforementioned downlink signal. The second converted signal is then subjected to a second resource demapping to demap the second converted signal into frequency resources and time resources. The second transformed signal to which the second resource demapping has been applied is subjected to an inverse Fourier transform to generate the first transformed signal. Applying a first resource demapping to the first conversion signal, the first conversion signal is demappled to a time resource or a logical resource. Multiple signals are generated from the first converted signal to which the first resource demapping has been applied. Terminal device.

19. Applying a first resource mapping to multiple signals to map multiple such signals to time resources or logical resources, A first transformed signal is generated by applying a Fourier transform to a plurality of signals to which the first resource mapping has been applied. Applying a second resource mapping to the first converted signal to map the first converted signal to frequency resources and time resources, The second transformed signal is generated by applying an inverse Fourier transform to the first transformed signal to which the second resource mapping has been applied, The process involves generating a downlink signal to which a single-carrier modulation scheme is applied from the second converted signal, A communication method that includes this.

20. Applying a Fourier transform to a downlink signal to which a single-carrier modulation scheme is applied generates a second transformed signal. Applying a second resource demapping to the second converted signal to demmap the second converted signal into frequency resources and time resources, The second transformed signal to which the second resource demapping has been applied is subjected to an inverse Fourier transform to generate the first transformed signal, Applying a first resource demapping to the first conversion signal to demmap the first conversion signal to a time resource or a logical resource, To generate multiple signals from the first converted signal to which the first resource demapping has been applied, A communication method that includes this.

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