First wireless device, second wireless device, wireless communication method, and wireless communication system

Abstract

A second wireless device according to one embodiment of the present disclosure comprises: a reception unit that receives one or more first signals and receives one or more second signals on the basis of the one or more first signals; a processing unit that determines one index from a plurality of indexes that are indicated in the one or more second signals; and a transmission unit that transmits a feedback signal that indicates the one index. When the one or more first signals are two or more first signals and the one or more second signals are two or more second signals, the processing unit determines, as the one index, an index that is indicated by the two or more second signals in an overlapping manner. According to one embodiment of the present disclosure, a first wireless device can appropriately determine a direction for the second wireless device.

Description

First radio device, second radio device, radio communication method, and radio communication system

[0001] This disclosure relates to a first wireless device, a second wireless device, a wireless communication method, and a wireless communication system.

[0002] In wireless communication systems such as the 5th generation mobile communication system New Radio (5G NR) of the 3rd Generation Partnership Project (3GPP®), it is being considered that access points (base stations) can identify the direction of terminals and control the directionality for data transmission and reception (for example, Patent Document 1, Non-Patent Document 1, and Non-Patent Document 2).

[0003] Japanese Patent Publication No. 2001-237755

[0004] P. Zhou, et al., “IEEE 802.11ay-Based mmWave WLANs: Design Challenges and Solutions,” in IEEE Communications Surveys & Tutorials, vol. 20, no. 3, pp. 1654–1681, 2018. Hattori, Fujioka, “5G Textbook—From LTE / IoT to 5G—,” Impress Publishing, 2018.

[0005] The problem lies in how the first radio device (e.g., an access point) determines the direction of the second radio device (e.g., a terminal) in order to control its directivity. If the first radio device cannot properly determine the direction of the second radio device, improvements in the system's communication throughput and frequency utilization efficiency may be suppressed.

[0006] Therefore, one of the objectives of this disclosure is to provide a first wireless device, a second wireless device, a wireless communication method, and a wireless communication system that can appropriately determine the direction from the first wireless device to the second wireless device.

[0007] A second wireless device according to one aspect of the present disclosure includes a receiving unit that receives one or more first signals and receives one or more second signals based on the one or more first signals, a processing unit that determines one index from a plurality of indices indicated in the one or more second signals, and a transmitting unit that transmits a feedback signal indicating the one index, wherein if the one or more first signals are two or more first signals and the one or more second signals are two or more second signals, the processing unit determines the index that is overlappingly indicated by the two or more second signals as the one index.

[0008] According to one aspect of this disclosure, the first wireless device can appropriately determine the direction of the second wireless device.

[0009] Figure 1 is a diagram showing an example of a schematic configuration of a system according to one embodiment of the present disclosure. Figure 2 is a diagram showing an example of a schematic functional configuration of each device according to one embodiment of the present disclosure. Figure 3 is a diagram showing an example of a schematic hardware configuration of each device according to one embodiment of the present disclosure. Figure 4 is a block diagram showing the functional configuration of a first wireless device according to Embodiment 1. Figure 5 is a block diagram showing the functional configuration of a second wireless device according to Embodiment 1. Figure 6 is a diagram showing an example of a wireless resource for common signal transmission and a wireless resource for feedback signal transmission according to Embodiment 1. Figure 7 is a diagram showing an example of a generator for generating a reference signal sequence. Figure 8 is a diagram showing an example of a spatial range and a partial range. Figure 9 is a diagram showing an example of a partial range index. Figure 10 is a diagram showing an example of a wireless resource for common signal transmission and a wireless resource for feedback signal transmission according to Embodiment 2. Figure 11 is a diagram showing an example of a wireless resource for common signal transmission and a wireless resource for feedback signal transmission according to Embodiment 3.

[0010] Embodiments of this disclosure will be described in detail below with reference to the drawings. In this specification and in the drawings, elements that can be similarly described are denoted by the same reference numerals, and redundant explanations can be omitted.

[0011] In this disclosure, text enclosed in parentheses () may indicate an explanation of the preceding text (e.g., a spelling explanation), a paraphrase, a specific example, or supplementary information. Similarly, text enclosed in square brackets ([]) may be interpreted as part of the overall meaning of the text, or as excluding (ignoring) the brackets. Note that parentheses () and square brackets ([]) may also be used for other purposes / meanings.

[0012] In this disclosure, "A / B" and "at least one of A and B" may be interpreted as mutually exclusive. In this disclosure, "A / B / C" may mean "at least one of A, B, and C".

[0013] In this disclosure, a Network Function (NF) may include, for example, at least one of the following: • Application Function (AF) (e.g., a function that provides an application server outside the 5G Core Network (5GC)), • Access and Mobility Management Function (AMF) (e.g., a function that manages UE registration, location, etc.), • Data Network (DN) (e.g., a function that provides a data network outside the 5GC), • Location Management Function (LMF) (e.g., a function that controls communication related to location information services), • Non-3GPP Inter-Working Function (N3IWF) (e.g., a function that connects an untrusted non-3GPP access network to the 5GC), • Network Exposure Function (NEF) (e.g., a function that provides an application interface for the 5GC's NF services to the outside), • Network Slice Selection Function (NSSF) (e.g., a function that selects a network slice), • Network Data Analytics Function (NWDAF) (e.g., a function that analyzes network data). - Operation, Administration and Maintenance (Management) (OAM) (e.g., a function that provides means for maintenance and operation management), - Policy Control Function (PCF) (e.g., a function that controls the quality and policies of data transfer paths), - Session Management Function (SMF) (e.g., a function that manages sessions), - Trusted Non-3GPP Gateway Function (TNGF) (e.g., a function that connects trusted non-3GPP access networks with 5GC),- Trusted WLAN Interworking Function (TWIF) (e.g., a function that connects a trusted non-3GPP access network to 5GC for non-5G UEs via a wireless local area network (LAN)), - Radio Access Network (RAN) (e.g., a function that provides a wireless access network), - User Equipment (UE) (e.g., a function that allows users to access network services via a wireless interface), - Unified Data Management (UDM) (e.g., a function that stores / manages subscriber information, UE authentication information, etc.), - Unified Data Repository (UDR) (e.g., a function that manages authentication / authorization based on subscriber information), - User Plane Function (UPF) (e.g., a function that transmits user data packets).

[0014] It should be noted that these are merely examples, and it is understood that other non-funding factors are also covered in this disclosure.

[0015] <System> Figure 1 is a diagram showing an example of a schematic configuration of a system according to one embodiment of the present disclosure. System 1 includes User Equipment (UE) 10, Base Station (BS) 20, Network (NW) 30, etc. System 1 may also be called a [wireless / information] communication system.

[0016] System 1 is, for example, a system that conforms to the 3GPP Technical Specification (TS). More specifically, for example, System 1 may be a system that conforms to the TS for 5th generation mobile communication system (5G) or New Radio (NR).

[0017] System 1 is not limited to this example and may include systems utilizing Long Term Evolution (LTE), LTE-Advanced (LTE-A), 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (where x is, for example, an integer or decimal)), New Radio (NR), Global System for Mobile communications (GSM®), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth®, and other wireless communication methods, as well as next-generation systems that are extended, modified, created, or defined based on these.

[0018] In other words, terms related to 5G in this disclosure can be interpreted as terms related to other technologies / systems. Furthermore, in such cases, it will be obvious to those skilled in the art that, for example, NF can be interpreted as having a similar function (or a device having a similar function) to the NF of 5G.

[0019] UE10 connects to NW30 via BS20. UE10 may also be called a terminal station and may be a mobile device (mobile communication terminal) such as a smartphone, tablet, or wearable device, or a fixed communication terminal. UE10 may be a device mounted on a moving object (e.g., a vehicle), the moving object itself, or a device included in the moving object (held by a person riding in the moving object).

[0020] UE10 may utilize (or be equipped with) a Subscriber Identity Module (SIM) / Embedded SIM (eSIM) of an operator providing wireless communication services using NW30. Furthermore, UE10 may switch connections to different operators' NW30s by switching the Access Point Name (APN) configuration profile.

[0021] BS20 provides a Radio Access Network (RAN) to UE10. The area where wireless communication is possible on the Radio Access Network is also called a cell. BS20 may be, for example, a gNB or an en-gNB.

[0022] The gNB provides NR user plane and control plane protocol terminations towards the UE and connects to the 5GC via the NG interface. The en-gNB provides NR user plane and control plane protocol terminations towards the UE and operates as a secondary node in E-UTRA-NR Dual Connectivity (EN-DC).

[0023] Multiple BS20s may be connected to each other by wire (e.g., fiber optics) or by wireless (e.g., NR communication). BS20s may be connected to NW30 directly or via other BS20s.

[0024] In System 1, UE10 provides wireless communication services using NW30. NW30 may be a cellular network to which UE10 can connect.

[0025] In this disclosure, cellular network may be interpreted as mobile network, wireless network, 5GC, Evolved Packet Core (EPC), 3GPP access network, etc. In this disclosure, 5GC, network, physical network, and core network (CN) may be interpreted as mutually exclusive.

[0026] NW30 may include at least one of the above-described NFs and provide the functionality of a 3GPP communication service. Furthermore, NW30 may be connected to an external NW (for example, a data network outside of 5GC), and UE10 may communicate with devices included in the external NW.

[0027] System 1 may include either or both a terrestrial network and / or a non-terrestrial network (NTN). An NTN is, for example, a network for satellite communications.

[0028] If System 1 includes NTN, communication between UE10 and BS20 may be transmitted via one or more NTN devices. In this disclosure, NTN devices may be interpreted as, for example, geostationary Earth Orbit (GEO) satellites, medium Earth Orbit (MEO) satellites, low Earth Orbit (LEO) satellites, high-altitude platform stations (HAPS), NTN payloads, NTN gateways, etc.

[0029] NTN (or System 1) may provide UE10 with non-terrestrial NR access via the NTN payload and NTN gateway. The radio link between the NTN payload and UE10 may be called a service link. The radio link between the NTN gateway and NTN payload may be called a feeder link.

[0030] In the present disclosure, a satellite such as a GEO satellite may correspond to a spacecraft orbiting the Earth that carries an NTN payload. The NTN payload may be a network node mounted on a satellite that provides a connection function between a service link and a feeder link. The NTN gateway may be a ground station located on the surface of the Earth that provides a connection function to the NTN payload using a feeder link.

[0031] The NTN payload may transparently transfer the radio protocol received from the UE10 (via the service link) to the NTN gateway (via the feeder link), or vice versa.

[0032] In the present disclosure, the BS20 may include at least one of a BS (earth station (or ground station)) in a terrestrial network, a BS in NTN, a BS (satellite station) on (or inside) the one or more NTN devices, and the like. In the present disclosure, the BS and the one or more NTN devices may be read interchangeably with each other.

[0033] The plurality of NTN devices may communicate directly with other NTN devices, for example, via an Inter-Satellite Link (ISL). The ISL may function as a satellite backhaul.

[0034] In the system 1, the communication link going to (received by) / coming from the UE10 to the BS20 may be called an uplink (UL), and the communication link going from (transmitted by) the BS20 to / coming to (received by) the UE10 may be called a downlink (DL).

[0035] In the system 1, a wireless access method based on Orthogonal Frequency Division Multiplexing (OFDM) may be used. For example, in DL / UL communication, Cyclic Prefix (CP)-OFDM, Discrete Fourier Transform (DFT)-Spread-OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), etc. may be used.

[0036] Note that any device shown in FIG. 1 may be referred to as a network node, a node, a server, a [wired / wireless] communication device, an information processing device, etc. Also, the lines between the devices in FIG. 1 indicate a logical connection relationship and may not be physically directly connected (they may be indirectly connected via another device).

[0037] <Configuration of Each Device> An example of the configuration of each device (e.g., UE10, BS20) according to an embodiment of the present disclosure will be described.

[0038] <<Functional Configuration>> FIG. 2 is a diagram showing an example of the schematic functional configuration of each device according to an embodiment of the present disclosure. For example, the UE10 includes a control unit 110, a communication unit 120, an input / output unit 130, and a storage unit 140.

[0039] Note that the BS20, other devices in the NW30, etc. may also have a similar functional configuration. For this reason, in FIG. 3, as the reference numerals of the functional blocks corresponding to each device, the numeral of the largest digit of the reference numeral indicating each device (e.g., for BS20, the largest digit of "20", which is "2") is replaced with "1". In the following, the functional blocks of the UE10 will be described, but it is understood that the same description will apply to other devices.

[0040] This example primarily shows the functional blocks of the characteristic parts of this embodiment, and each device may also have other functional blocks necessary for other processes. Furthermore, the configuration may omit some functional blocks.

[0041] The control unit 110 controls the UE 10 and provides various functions. For example, the control unit 110 may control communication with other devices via the communication unit 120. The control unit 110 may also acquire information necessary for processing based on information received via the communication unit 120. The control unit 110 may also be called a processing unit.

[0042] The communication unit 120 communicates (transmits / receives) with other devices via wired / wireless connections. The communication unit 120 may obtain information from the received signals and output it to the control unit 110, or it may convert information input from the control unit 110 into a signal and transmit it. The communication unit 120 may be configured as an integrated transmitting / receiving unit (a unit capable of both transmitting and receiving), or it may be composed of separate transmitting and receiving units.

[0043] The input / output unit 130 may include an input unit that accepts input from a human operator or acquires information by performing measurements (sensing) of the surrounding environment. The input unit may be connected to a predetermined device, storage medium, etc., and accept data input. The input unit may output the input results to, for example, the control unit 110.

[0044] Furthermore, the input / output unit 130 may include an output unit that outputs data, content, etc., in a format perceptible to humans. The output unit may include a display unit that displays images, an audio output unit that outputs sound, and the like.

[0045] Either the communication unit 120 or the input / output unit 130, or a combination thereof, may function as a sensing transmitter / receiver. Sensing performed via the communication unit 120 may be wireless sensing, and sensing performed via the input / output unit 130 may be non-wireless sensing. The sensing unit may be called a sensing unit, a measurement unit, etc. For example, the measurement unit may acquire sensed data by performing sensing.

[0046] The memory unit 140 stores (holds) various information that the UE 10 uses for processing. The control unit 110 may instruct the memory unit 140 to read or write data.

[0047] <<Hardware Configuration>> Figure 3 is a diagram showing an example of the schematic hardware configuration of each device according to one embodiment of the present disclosure. Each device comprises an antenna 910, a radio frequency (RF) circuit 920, a processor 930, a network interface 940, an input / output device 950, a memory 960, and a storage 970.

[0048] For example, the control unit X10 (X=1, 2; the same applies hereinafter) described above may be implemented by a processor 930. The communication unit X20 may be implemented by an antenna 910 / RF circuit 920 / network interface 940. The input / output unit X30 may be implemented by an input device / output device 950. The storage unit X40 may be implemented by a memory 960 / storage 970.

[0049] The hardware configuration of each device may include one or more of the elements shown in Figure 3, or it may be configured without some of the elements. For example, UE10 does not need to have a network interface 940.

[0050] Antenna 910 converts a signal into radio waves and radiates the radio waves into space. Antenna 910 also receives radio waves in space and converts the radio waves into signals. Multiple antennas 910 may be mounted, or they may include a transmitting antenna and a receiving antenna, or they may include a single antenna for transmitting and receiving. Antenna 910 may include a directional antenna, or it may include multiple antenna elements.

[0051] The RF circuit 920 performs analog processing on the signals transmitted and received via the antenna 910. The RF circuit 920 may include filters (e.g., high-frequency filters, low-pass filters), amplifiers, modulators, frequency synthesizers, analog-to-digital conversion circuits, digital-to-analog conversion circuits, Fast Fourier Transform (FFT) / Inverse Fast Fourier Transform (IFFT) processing circuits, and the like.

[0052] The RF circuit 920 may perform amplification, filtering, and demodulation to a baseband signal on the received radio frequency band signal and output it to the processor 930. The RF circuit 920 may also perform modulation to a radio frequency band, filtering, and amplification on the baseband signal input from the processor 930 and transmit the radio frequency band signal via the transmitting and receiving antenna 910. The RF circuit 920 may also perform physical layer processing (for example, processing of lower-level functions of the physical layer), and may perform beamforming processing such as analog beamforming and digital beamforming.

[0053] The processor 930 may control the entire device. The processor 930 may read programs (program code), software (software modules), data, etc., from the storage 970 into the memory 960 and perform various processes accordingly. For example, the processor 930 may execute and control an operating system (OS) program loaded into the memory 960.

[0054] The processor 930 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic units, registers, etc. The processor 930 may also include a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), a field-programmable gate array (FPGA), a graphics processing unit (GPU), a neural processing unit (NPU), and the like.

[0055] The processor 930 may perform digital processing of signals transmitted and received via the antenna 910 and the RF circuit 920. This digital processing may include processing at the physical layer (e.g., processing of higher-level functions of the physical layer), processing at layers above the Medium Access Control (MAC) layer, and processing such as modulation, demodulation, coding, decoding, and scrambling. The processor 930 also processes signals transmitted and received via the network interface 940.

[0056] The processor 930 may include multiple processors or it may be a single processor. The multiple processors may include a baseband processor that performs the digital processing and one or more processors that perform other processing (for example, overall control).

[0057] The network interface 940 may be, for example, a network adapter, which is connected to an external network via a wired connection and performs signal transmission and reception.

[0058] The RF circuit 920, processor 930, and network interface 940 may be configured as an integrated unit. The RF circuit 920, processor 930, and network interface 940 may also be referred to as a network controller, network card, communication module, etc.

[0059] The input / output device 950 includes input devices that accept input from the outside or acquire information about the surrounding environment (e.g., keyboard, mouse, microphone, switch, button, camera, sensor, etc.), output devices that perform output to the outside (e.g., display, speaker, Light Emitting Diode (LED) lamp, etc.), and devices that integrate these (e.g., touch panel). A locator for acquiring location information (e.g., a receiver compatible with Global Navigation Satellite System (GNSS)) may also be included as a sensor.

[0060] Memory 960 is a computer-readable non-temporary recording medium that stores programs executed by the processor 930, parameters related to those programs, and various other information. Memory 960 may include at least one of Read Only Memory (ROM), Erasable Programmable ROM (EPROM), (Electrically EPROM (EEPROM)), Random Access Memory (RAM), and flash memory. All or part of memory 960 may be contained within the processor 930. Memory 960 may also be called registers, cache, main memory, etc.

[0061] The storage 970 is a computer-readable non-temporary recording medium that stores various types of information. The storage 970 may include, for example, at least one of the following: a flexible disk, a floppy disk, a magneto-optical disk (e.g., Compact Disc ROM (CD-ROM)), a digital multipurpose disk, a Blu-ray (registered trademark) disk), a removable disk, a hard disk drive (HDD), a smart card, or a flash memory device (e.g., a Solid State Drive (SSD)). The storage 970 may also be called an auxiliary storage device.

[0062] Furthermore, each device, such as the processor 930 and the memory 960, may be connected by a bus for communicating information. A single bus may be used within the device, or different buses may be used between the devices.

[0063] Furthermore, BS20 may be separated into three elements: a Radio Unit (RU), a Distributed Unit (DU), and a Central Unit (CU). The RU implements RF processing and lower-level functions of the physical layer. The DU implements higher-level functions of the physical layer, MAC layer functions, and Radio Link Control (RLC) layer functions. The CU implements Packet Data Convergence Protocol (PDCP) layer, Service Data Adaptation Protocol (SDAP), and Radio Resource Control (RRC) layer functions.

[0064] In this disclosure, BS20 may include one device that implements all of the functions of RU, DU, and CU, or it may include multiple devices, each implementing some of the functions of RU, DU, and CU.

[0065] For example, BS20 may consist of a Remote Radio Unit (RRU) that relays UE10 and gNB, and the gNB itself. The RRU may include an NTN payload located on the satellite and an NTN gateway located on the ground. Alternatively, BS20 may consist of a gNB located on the satellite that communicates with UE10, and an NTN gateway located on the ground.

[0066] Furthermore, other devices in this disclosure may also be implemented by multiple devices that are physically separated from each other. Conversely, multiple different devices in this disclosure (for example, two or more of UE10, BS20, NF server 30, and application server 40) may be implemented as a single device.

[0067] Furthermore, all or part of the devices described herein may mean logical devices implemented by virtual machines, containers, Docker, etc., or physical devices that operate such logical devices.

[0068] <Terminal Location Identification Method> This embodiment relates to a first wireless device (e.g., an access point) that provides wireless access to a second wireless device (e.g., a terminal) using a directional antenna, and a second wireless device that connects to the first wireless device to send and receive data. The terminal may be a personal computer (PC), a mobile terminal, an Internet of Things (IoT) terminal, etc.

[0069] Cellular wireless communication systems, developed to enable voice calls while moving, regardless of the location of the telephone's telephone line connection, are now used not only for voice calls but also for a wide variety of services that utilize information and communication technology. Furthermore, their use is expanding beyond human access via handheld terminals to include the remote control of various sensors and industrial machinery in industrial fields.

[0070] Meanwhile, wireless LANs (Local Area Networks), developed to easily connect personal computers to computer networks in offices and homes, are also used when accessing a wide variety of services that utilize information and communication technology. Therefore, although cellular wireless communication systems and wireless LANs differ in the geographical extent of communication and the contract types that enable communication, they are indistinguishable from services that utilize information and communication technology.

[0071] Regarding services utilizing information and communication technology, the initial services were implemented by sending and receiving short text messages, but they have expanded to include the transmission and reception of image, music, and video data. In particular, recent services have expanded to transmit higher-resolution, higher-quality video data and virtual reality environments, and the amount of data to be transmitted continues to increase. Furthermore, there is a growing demand for connecting a large number of devices at once.

[0072] Cellular wireless communication systems and wireless LANs have so far responded to the increase in the amount of communication data by introducing technologies that increase the amount of data that can be transmitted per unit frequency bandwidth of radio waves, such as MIMO (Multi-Input Multi-Output) communication channels that use high-order modulation schemes and a large number of antenna elements, and by increasing the frequency bandwidth used by the system.

[0073] Here, using higher-order modulation schemes requires high-precision signal processing, which increases the burden on the implementing hardware. Furthermore, the transmission power required for such modulation schemes increases more than the increase in the bit rate of the transmitted information, making the use of such modulation schemes undesirable from a power utilization efficiency standpoint. In addition, under certain propagation conditions, there is a limit to the amount of information that can be transmitted in a MIMO communication channel. Therefore, it is difficult to increase the amount of data that can be transmitted per unit frequency bandwidth of radio waves any further.

[0074] Therefore, increasing the amount of data transmitted requires increasing the frequency bandwidth used by the communication system. However, it is difficult to secure new frequency bands that can be used by cellular wireless communication systems and wireless LANs in the frequencies below approximately 6 GHz, where existing radio wave utilization systems such as broadcasting, satellite positioning and sensing, weather radar, police and fire department radio, aircraft and ship radio, and amateur radio are concentrated.

[0075] Therefore, the use of millimeter waves, which represent radio waves with frequencies generally between 10 GHz and 100 GHz, sub-terahertz waves exceeding 100 GHz, and terahertz waves ranging from 1 to 10 THz in cellular wireless communication systems and wireless LANs is being considered. In 3GPP (registered trademark), a cellular wireless communication standard mainly using millimeter waves in the 28 GHz band has been created and is being put into practical use in some areas. In IEEE (registered trademark), technical standards such as 802.11ad and 802.11ay, which are wireless LAN standards using the 60 GHz band, and 802.15.3d, which uses the 300 GHz band for point-to-point communication, have been created. With these millimeter waves, sub-terahertz waves, and terahertz waves, a large block of bandwidth can be used at once. For example, the IEEE 802.11ad standard uses a basic bandwidth of 2.16 GHz, and allows the use of a bandwidth of 8.7 GHz by bundling four of these together, while the 802.15.3d standard allows the use of a bandwidth of up to 69 GHz by bundling up to 32 of these together. Such a wide bandwidth cannot be secured at frequencies below 6 GHz.

[0076] According to Friis's transmission formula, the received power Pr at the receiving end when radio waves propagate in free space is given by the following equation (1):

[0077] λ, d, G ｒ G ｔ , P ｔThese are the wavelength of the radio wave, the distance between the transmitting and receiving points, the directional gain of the receiving antenna, the directional gain of the transmitting antenna, and the transmitted power, respectively. Since the wavelength decreases inversely with frequency, the received power decreases inversely with the square of the frequency. In propagation paths that are not free space, such as indoors or on the street, it is statistically known that the received power may deviate from the square of the frequency, but the received power still decreases at values ​​close to the square of the frequency. Therefore, in communications using high frequencies, one or both of the transmitting and receiving radio devices must use antennas with high directional gain to compensate for the decrease in received power. An antenna with directional gain is an antenna that concentrates and radiates radio waves in a specific direction, or strongly receives radio waves coming from a specific direction, while the intensity of radio waves radiated or received in other directions is weaker, and is often called a beam antenna. Directivity in a specific direction is often called a beam. If the intensity of radio waves transmitted and received at an angle θ / 2° away from the center of the directivity is -3 dB, or 1 / 2, compared to the center of the directivity, then θ is called the half-power angle, and there is roughly the following relationship between it and the antenna's directivity gain G: equation (2).

[0078] For example, the half-power angle of an antenna with a directional gain of 30 dB (G = 1000) is approximately 6°. The higher the directional gain, the narrower the half-power angle.

[0079] In cellular wireless communication systems and wireless LANs, terminal devices such as smartphones and laptops used by humans, as well as communication modules attached to various sensors and industrial machinery, connect to wireless base stations and access points according to predetermined standards, and communicate with the terminals of the communication partners or the computers that provide the applications and services they use through these connections. Hereinafter, wireless base stations in cellular wireless communication systems and access points in wireless LANs will be collectively referred to as "access points." Similarly, smartphones, laptops, and communication modules attached to various sensors and industrial machinery will be collectively referred to as "terminals."

[0080] Access points periodically transmit information that allows terminals to connect to them. Terminals then send connection request signals to the access point according to this information. After the access point receives the signal and performs connection procedures such as authentication, the access point and terminal become connected, and data can be sent and received.

[0081] During the connection process or the data transmission / reception phase after the connection process is completed, if the terminal's location or direction from the access point is specified, the access point can use a directional antenna to transmit data to the terminal, thereby increasing the signal-to-noise ratio (S / N) and enabling high-speed, low-error data communication. At the same time, the radio wave strength in directions other than the direction in which the terminal is located will be weakened, reducing interference to communications of other access points and terminals using the same radio frequency, and improving the quality of communication at those access points and terminals. When the access point receives a signal, using a directional antenna also increases the S / N of the received signal and reduces interference from communications of access points and terminals outside the directional range.

[0082] The access point transmits a discovery signal, directed towards various directions in which the terminal may be located, to allow the terminal to discover the access point. The terminal receives the signal most strongly when the discovery signal is transmitted from the access point toward the terminal, and thereby discovers the access point. The terminal then transmits a response signal to the access point at a predetermined position on the radio frame or at a position on the radio frame based on the information contained in the discovery signal. If the discovery signal contains information identifying the directionality used by the access point when transmitting the discovery signal, the response signal will contain that information, or the position on the radio frame in which the response signal is transmitted will be determined from the position on the radio frame in the discovery signal received by the terminal. In this way, the access point that receives the response signal can determine the directionality used by the terminal when transmitting the discovery signal, based on the information identifying the directionality used when transmitting the discovery signal, or based on the position on the radio frame in which the response signal was received, and can determine that the terminal is located in that direction.

[0083] For example, in the IEEE 802.11ad standard, an access point transmits an initiator sector sweep (ISS) signal at the beginning of a beacon transmission interval (BTI) called the Beacon header interval (BHI) in the beacon signal it transmits periodically. The ISS signal consists of multiple training signals, each containing information that identifies the directionality used when it is transmitted. When a terminal responds to a beacon signal transmitted by an access point, it is supposed to include information in its response signal that identifies the directionality contained in the training signal it received most strongly. The access point uses this information to identify the directionality used when the terminal transmitted the training signal it received most strongly, and determines that the terminal is located in that direction.

[0084] Furthermore, the cellular wireless communication standard defined by 3GPP specifies multiple time positions in a wireless frame where an access point transmits a signal block called a Synchronization Signal Block (SSB), and that the access point transmits the SSB using a different directivity at each time position. The terminal sends a request signal to the access point requesting connection at the location on the wireless frame where the SSB was received most strongly, or at a location on the wireless frame that corresponds to the Physical Broadcast channel (PBCH) in that SSB and any additional information received. The access point identifies the directivity used when the terminal transmitted the SSB that was received most strongly, based on the location on the wireless frame where the request signal was sent, and determines that the terminal is located in that direction.

[0085] The directivity used by an access point when transmitting a discovery signal may be broader than the access point's transmitter's ability to form, in order to ensure reception regardless of the terminal's location. Furthermore, since the response signal transmitted by the terminal in response to the discovery signal is expected to arrive from the same direction as the directivity used when the discovery signal was transmitted, the access point sets the receiver to a directivity equivalent to the directivity used when the discovery signal was transmitted at locations on the wireless frame where the terminal is likely to transmit a response signal in response to the transmitted discovery signal, in order to detect whether the terminal has transmitted a response signal.

[0086] Methods being considered for an access point to determine the direction in which a terminal is located include a method in which the access point transmits a discovery signal with directional properties directed towards various possible directions in which the terminal may be located, and the direction of the terminal is determined by the response signal transmitted by the terminal in response to one of these signals, as well as a method in which the access point transmits reference signals from multiple antennas, and the terminal transmits the phase difference when it receives these signals to the access point as a feedback signal to determine the direction of the terminal.

[0087] In methods where an access point determines the direction of a terminal based on a response signal transmitted by the terminal in response to a discovery signal, or where an access point determines the direction of a terminal by transmitting the phase difference when the terminal receives a reference signal transmitted by the access point from multiple antennas as a feedback signal from the terminal to the access point, a signal is transmitted from the terminal to the access point in both cases.

[0088] In a method in which a terminal that receives a discovery signal transmits a response signal to an access point, if the terminal's location is determined by the discovery signal, the terminal's location can be determined to be within the range of the directivity used when the discovery signal was transmitted, based on the information identifying the directivity included in the discovery signal and the position on the radio frame in which the terminal transmits the response signal. However, this method cannot determine the terminal's location within a more granular range.

[0089] For example, in NTN, a LEO altitude of 600 km provides a service area with a ground diameter of approximately 1600 km. However, using a directional antenna with a beam half-power angle of 5°, the ground beam diameter becomes approximately 50 km. To cover the entire service area, the total number of beams that the access points on the satellite must support exceeds 1000. However, under conditions where the number of beams that can be transmitted simultaneously is limited due to the power available on the satellite, transmitting signals to discover access points at the predetermined intervals required by the 3GPP specification results in the problem that it is not possible to support all of the more than 1000 beams. For this reason, it is being considered to reduce the total number of beams to which signals are transmitted for discovering access points by forming a wider directivity than the directivity capability of the access point's transmitter.

[0090] When performing data communication, it is desirable to improve the signal-to-noise ratio (S / N) and reduce interference from the surroundings to achieve faster communication with a lower error rate, as well as to form sharper directivity to reduce interference to the surroundings. However, if the access point's transmitter forms a wider directivity than it has the ability to form, and the total number of beams used to transmit signals to discover the access point is reduced, a problem arises where the terminal's location can only be determined within the range of the formed wide directivity, making it impossible to form the sharp directivity desired for data communication.

[0091] On the other hand, if an access point were to transmit reference signals from multiple antennas and the terminal received them, and then sent a feedback signal to the access point based on the phase difference, it would be possible to determine the terminal's position regardless of the range of directivity used when transmitting the discovery signal. However, before the access point receives the feedback signal, it has no prior information about the terminal's position, and the access point must be able to receive the feedback signal from the terminal regardless of its location. Consequently, the access point may not be able to set appropriate directivity in its receiving section when receiving the feedback signal, and there is a possibility that the feedback may not be of sufficient quality.

[0092] Regarding the setting of directivity for receiving feedback signals, it is being considered that the access point provides the terminal with information on radio resources corresponding to the terminal's location, determined by the phase difference or the terminal's position when a reference signal transmitted from multiple antennas of the access point is received. The terminal then uses the radio resources according to this information to provide feedback, and the access point sets appropriate directivity for each radio resource that may receive feedback to receive the feedback signal.

[0093] However, in order to implement these methods, the access point needs to be equipped with multiple transmitting antennas, each transmitting a reference signal, and the terminal side also needs to measure the phase difference when receiving these multiple reference signals. This presents the problem of complicating the equipment configuration for both transmission and reception.

[0094] Therefore, the inventors have conceived a method for a first radio device (e.g., an access point, base station, satellite station, or ground station) to determine the location of a second radio device (e.g., a terminal or mobile device).

[0095] According to one aspect of this disclosure, the access point can determine the location of a terminal with greater precision than the spatial range of the directivity used when transmitting the reference signal, without the access point using multiple antennas to transmit a reference signal, nor without the terminal measuring the phase difference when receiving signals transmitted from multiple antennas of the access point, and the terminal can set appropriate directivity in the radio resource transmitting the feedback signal for reception. This enables the access point to receive the feedback signal with high quality.

[0096] In this disclosure, the first signal, reference signal, discovery signal, beacon, pilot signal, synchronization signal (SS), primary synchronization signal (PSS) / secondary synchronization signal (SSS), SSB, SS / physical broadcast channel (PBCH) block, reference signal, channel state information reference signal (CSI-RS), [transmit / receive] [reference] signal sequence, and data sequence may be interpreted as interchangeable. In this disclosure, the second signal, radio resource information [signal], index [information] [signal], [transmit / receive] [radio resource information] signal sequence, data sequence, determination condition, system information, PBCH, MIB, SIB, [for feedback signal transmission] radio resource, index [information] [signal], and feedback signal attribute information [signal] may be interpreted as interchangeable. In this disclosure, the common signal, broadcast signal, burst, signal group, reference signal and at least one of the radio resource information signals, reference signal and at least one of the index information signals, and the first signal and at least one of the second signal may be interpreted as interchangeable.

[0097] In this disclosure, feedback [signal], index, index [information] field, connection request signal, PRACH, random access channel, UL individual signal, physical uplink control channel (PUCCH), physical uplink shared channel (PUSCH), and [UL] control data may be interpreted as each other. In this disclosure, DL individual signal, physical downlink control channel (PDCCH), physical downlink shared channel (PDSCH), and system information may be interpreted as each other. In this disclosure, [UL / DL] individual signal, data [signal], [UL / DL] control data, [UL / DL] control channel, [UL / DL] shared channel, [UL / DL] communication data, [UL / DL] user data, feedback signal, [transmit / receive] [individual] signal sequence, and data sequence may be interpreted as each other.

[0098] In this disclosure, [for feedback signal transmission] [UL] radio resources / attributes, time / frequency / sequence resources, random access resources, and random access occasions may be interpreted as interchangeable. In this disclosure, the [location / area (latitude / longitude) / spatial range / partial range] of the second radio device [relative to the first radio device] [on the ground surface], the direction (azimuth / elevation) [relative to the first radio device / antenna plane], and the beam / reference signal [ID] [for data transmission / reception] may be interpreted as interchangeable. In this disclosure, the multiple antennas, array antennas, panels [of which multiple antennas are arranged] of the first radio device may be interpreted as interchangeable. In this disclosure, directivity, beam, and half-power angle may be interpreted as interchangeable.

[0099] In this disclosure, spatial scope, partial scope, [large / small / macro / micro] cell [group], and area may be interpreted as equivalent to each other.

[0100] In this disclosure, the location / area / direction / spatial range / partial range of the second radio device may be associated with the radio resource / attribute / value / index of the feedback signal. In this disclosure, reporting / notifying the location of the second radio device, transmitting the feedback [signal], transmitting a PRACH, transmitting a PUCCH / PUSCH [including the feedback signal] may be interpreted as mutually exclusive.

[0101] The first signal (e.g., a reference signal) may be included in the SSB, for example. The second signal (e.g., a radio resource information signal or an index information signal) may be included in the system information (e.g., an SIB), for example. The first signal may indicate the radio resources for the second signal (the second signal may be scheduled). The second radio device may receive / detect / decode the first signal and receive / detect / decode the second signal based on the first signal.

[0102] <Examples of Operation> Below, examples of the operation of each device / function according to the embodiments of this disclosure will be described. The communication methods (wireless communication methods, control methods) described below may be applied in the system 1 described above.

[0103] In the following descriptions of this disclosure, reference numerals may be omitted. For example, UE in the following descriptions may mean UE10.

[0104] In the following description, each device / function may be interpreted as one or more functional blocks (e.g., control unit 110, communication unit 120) or hardware configuration (e.g., RF circuit 920, processor 930) within the device / function.

[0105] In the following description, the first radio device can be applied to an access point / satellite station / ground station / base station / BS20 in a cellular radio communication system / NTN / wireless LAN, and these terms may be interchangeable. In the following description, the second radio device can be applied to a terminal / mobile device / UE10 in a cellular radio communication system / NTN / wireless LAN, and these terms may be interchangeable.

[0106] <<Embodiment 1>> Figure 4 is a block diagram showing the functional configuration of a first wireless device 20 according to Embodiment 1 of the present disclosure. Figure 5 is a block diagram showing the functional configuration of a second wireless device 10 according to Embodiment 1 of the present disclosure.

[0107] <<<First Radio Device>>> As shown in Figure 4, the first radio device 20 includes a common signal transmitting antenna 350. The common signal transmitting antenna is used to transmit one or more common signals to the second radio device 10 before establishing a connection state with the first radio device 20 (e.g., RRC_CONNECTED state). One or more common signals may be transmitted periodically. The common signals may include a reference signal and a radio resource information signal. The reference signal may be a signal for the second radio device 10 to discover the presence of the first radio device 20. The radio resource information signal may include one or more radio resource information. The radio resource information may indicate a [feedback transmission] radio resource for the second radio device 10 to transmit a feedback signal to the first radio device 20. The common signal transmitting antenna may be a directional antenna capable of forming directivity toward a predetermined spatial range on the ground. When the second radio device 10 is within a predetermined spatial range, the second radio device 10 can receive a reference signal transmitted by the first radio device 20 to detect the presence of the first radio device 20, obtain a radio resource information signal, etc., and transmit a feedback signal to the first radio device 20.

[0108] The common signal transmitting antenna 350 of the first radio device 20 may be a directional antenna capable of forming different directivity toward different spatial ranges. This allows the first radio device 20 to transmit a common signal toward each of several different spatial ranges. The second radio device 10, located in one of the different spatial ranges, can receive the common signal transmitted from the common signal transmitting antenna 350, which has formed directivity toward its own spatial range, and transmit a feedback signal to the first radio device 20. The parts of the several different spatial ranges from which the first radio device 20 transmits multiple common signals may overlap.

[0109] The first radio device 20 also includes one or more individual signal transmitting and receiving antennas 450. The individual signal transmitting and receiving antennas are used when transmitting and receiving individual signals between the first radio device 20 and the second radio device 10, which has established a connection state. The individual signal transmitting and receiving antennas may be directional antennas that can form directivity in the direction of the second radio device 10. If the first radio device 20 transmits and receives individual signals with its directivity directed towards the second radio device 10, the signal-to-noise ratio is improved, enabling faster transmission and reception of individual signals. The individual signals include communication data and control data exchanged between the first radio device 20 and the second radio device 10. The control data may include feedback signals.

[0110] The directivity / beam (half-power angle) of individual signal transmitting / receiving antennas may be narrower than that of common signal transmitting antennas. The total / maximum number of beam candidates / IDs formed by individual signal transmitting / receiving antennas may be greater than the total / maximum number of beam candidates / IDs formed by common signal transmitting antennas. The beam formed by individual signal transmitting / receiving antennas (for transmitting / receiving individual signals) may be called a narrow beam. The beam formed by common signal transmitting antennas (for transmitting common signals) may be called a wide beam. The ground area / range covered by a wide beam may include the ground areas / range covered by multiple narrow beams.

[0111] The antenna for common signal transmission and the antennas for individual signal transmission and reception may be array antennas. An array antenna is an antenna in which many antenna elements are arranged in a row, and directivity can be formed in a specific direction by adding an appropriate phase shift to the signals supplied to each antenna element during transmission, and by adding an appropriate phase shift to the signals received by each antenna element during reception and combining them.

[0112] When a common signal transmitting antenna and individual signal transmitting / receiving antennas are configured as an array antenna, the common signal transmitting antenna and the individual signal transmitting / receiving antennas can share antenna elements. Generally, the directivity of an array antenna composed of fewer elements is wider than that of an array antenna composed of more elements. Therefore, by sharing some of the antenna elements that make up the individual signal transmitting / receiving antenna as antenna elements that make up the common signal transmitting antenna, the beam formed by the common signal transmitting antenna can be made wider than the beam formed by the individual signal transmitting / receiving antenna. When antenna elements are shared, amplifiers and the like in the radio units 340 and 440 corresponding to the shared antenna elements can also be shared.

[0113] As shown in Figure 4, the first wireless device 20 shows processing blocks related to the transmission of a common signal and the transmission and reception of individual signals. The first wireless device 20 also has other processing blocks and a power supply unit, but these are not directly necessary for explaining this embodiment and are therefore omitted from the illustration.

[0114] As shown in Figure 4, the first wireless device 20 includes, in addition to the common signal transmission antenna 350 and the individual signal transmission / reception antenna 450, a wireless protocol control unit 310, a reference signal generation unit 320, a wireless resource information signal generation unit 360, a transmission individual signal generation unit 420, a reception individual signal processing unit 470, baseband signal generation units 330 and 430, a baseband signal processing unit 460, and wireless units 340 and 440. Processing blocks other than the wireless units 340 and 440 can be realized by hardware such as a processor 930 (e.g., CPU) and memory 960, and software that performs the calculation processing described below.

[0115] When the wireless protocol control unit 310 decides to transmit a common signal including a reference signal and a wireless resource information signal, it is configured to instruct the reference signal generation unit 320 to generate a reference signal, the wireless resource information signal generation unit 360 to generate a wireless resource information signal, and the wireless unit 340 to add an appropriate phase shift to the signals supplied to each antenna element of the common signal transmitting antenna 350 (control of the directivity of the common signal transmitting antenna 350) at the timing of transmission, so that the common signal is transmitted with directivity directed toward a predetermined spatial range. Alternatively, the first wireless device 20 can be configured so that the baseband signal generation unit 330 adds an appropriate phase shift to the signals supplied to each antenna element instead of the wireless unit 340.

[0116] The first wireless device 20 may be configured such that the common signal transmitting antenna 350 forms multiple directivity points toward multiple different spatial ranges, and a different reference signal (common signal) is transmitted in each of the multiple directivity points. The wireless resource information signal for each reference signal may include multiple wireless resource information. Each wireless resource information may indicate a wireless resource for [feedback signal transmission]. In addition, multiple directivity points may be formed such that parts of multiple different spatial ranges overlap each other.

[0117] Multiple common signals transmitted by multiple directivity signals directed to multiple different spatial ranges may be transmitted simultaneously at the same frequency, or they may be transmitted with predetermined frequency and time differences. In other words, multiple common signals may be code division multiplex (CDM), frequency division multiplex (FDM), or time division multiplex (TDM). Radio resource information signals for each directivity signal directed to a spatial range may contain multiple radio resource information. If there is overlap in parts of multiple different spatial ranges, multiple radio resource information signals transmitted using directivity signals directed to those multiple spatial ranges may contain the same (common) radio resource information.

[0118] The second radio device may receive a reference signal, and according to the timing of the reception of the reference signal and the information obtained from the reference signal, further obtain a radio resource information signal, and transmit a feedback signal to the first radio device 20 using the radio resources indicated by that information. If the radio resource information signal contains multiple pieces of radio resource information, the feedback signal may be transmitted using the radio resources indicated in any of the multiple pieces of radio resource information. If multiple radio resource information signals are obtained corresponding to multiple different reference signals, and the multiple radio resource information signals contain common radio resource information, the feedback signal may be transmitted using the radio resources indicated in the common radio resource information. The radio resource information may be transmitted from the first radio device, or it may be transmitted from the first radio device and held by the second radio device.

[0119] As shown in the example in Figure 6, several common signaling [DL] radio resources and several feedback signaling [UL] radio resources may be configured by the first radio device or defined in the specification. In the example in Figure 6, the several common signaling radio resources are common signaling radio resource #1 for transmitting common signal #1 including reference signal #1 and radio resource information signal #1, and common signaling radio resource #2 for transmitting common signal #2 including reference signal #2 and radio resource information signal #2. The several feedback signaling radio resources may be feedback signaling radio resources #1 to #5.

[0120] The first radio device may set a directivity #1 toward a certain spatial range #1 in the signal block transmission radio resource #1 and transmit a common signal #1 including a reference signal #1 and a radio resource information signal #1. The first radio device may set a directivity #2 toward a different spatial range #2 from spatial range #1 in the signal block transmission radio resource #2 and transmit a common signal #2 including a reference signal #2 and a radio resource information signal #2. The radio resource information signal indicates several feedback signal transmission radio resources. In the example in Figure 6, the radio resource information signal #1 indicates three radio resources #1, #2, and #3 from the feedback signal transmission radio resources #1 to #5. Similarly, the radio resource information signal #2 indicates three radio resources #1, #4, and #5 from the feedback signal transmission radio resources #1 to #5. Each radio resource information in the radio resource information signal may indicate a feedback signal transmission radio resource by its relative position with respect to a common signal transmission radio resource used for transmitting a common signal.

[0121] A second radio device that has received reference signal #1 and radio resource information signal #1 may select one of the radio resources for transmitting feedback signals indicated by radio resource information signal #1 and transmit a feedback signal. A second radio device that has received both reference signal #1 and radio resource information signal #1, and reference signal #2 and radio resource information signal #2, may select radio resource #1, which is commonly indicated by both radio resource information signals, and transmit a feedback signal using radio resource #1.

[0122] The reference signal may be a PSS or SSS according to the cellular wireless communication specifications defined by 3GPP. Alternatively, it may be an SSB including PSS, SSS, and PBCH. The radio resource information signal may be a PDSCH including one or more radio resource information as part of the SIB. The feedback signal may be a signal or PRACH requesting connection to the first radio device 20.

[0123] The wireless protocol control unit 310 is further configured to receive individual signals (communication data and control data including feedback signals) transmitted by the second wireless device from the received individual signal processing unit 470, analyze their contents, and send the communication data outside the device (or to a higher layer of the device) or reflect the control data in subsequent wireless protocol processing. The operation of reflecting the control data in subsequent wireless protocol processing includes, according to the wireless resource that has received a feedback signal from the second wireless device, recognizing that the second wireless device is located in an overlapping spatial range [corresponding to that wireless resource] among a plurality of spatial ranges, and thereafter controlling the directivity of the directional antenna (individual signal transmission / reception antenna 450) used when transmitting and receiving individual signals with the second wireless device. The transmission of a feedback signal as a connection request signal (connection request signal) by the second wireless device, which is not connected to the first wireless device (for example, in the RRC_IDLE state or RRC_INACTIVE state), may be included in the initial connection (initial access) process between the second wireless device and the first wireless device.

[0124] The reference signal generation unit 320 is configured to generate a data sequence defined as a reference signal (hereinafter also referred to as the "reference signal sequence") at a timing instructed by the wireless protocol control unit 310, and to send the generated reference signal sequence to the baseband signal generation unit. Figure 7 shows an example of a generator that generates a reference signal sequence. According to the generator in Figure 7, a Gold sequence consisting of two M sequences generated according to the generation polynomials of equations (3) and (4) below may be generated.

[0125] The reference signal generation unit 320 is configured to use a common initial value #1 for all directivity signals transmitting a reference signal, and to provide different initial values ​​#2 for reference signals transmitted with directivity directed towards different spatial ranges, thereby transmitting reference signals according to different reference signal sequences with different directivity directions. The reference signal sequence can be a Gold sequence generated by the generator shown in Figure 7, or a Walsh-Hadamard sequence, Zadoff-Chu sequence (low peak-to-average power ratio (PAPR) sequence), or any other sequence with low cross-correlation. The Walsh-Hadamard sequence is an example of a sequence with zero cross-correlation. Depending on the type of sequence, the generator's initial value, sequence group number, sequence number, [initial] cyclic shift index, etc., may differ between multiple reference signal sequences. While the Gold and Walsh-Hadamard sequences generated by the generator shown in Figure 7 consist of binary values ​​of "1" or "-1", sequences like the Zadoff-Chu sequence can be represented by complex numbers.

[0126] The wireless resource information signal generation unit 360 is configured to generate a wireless resource information signal (hereinafter also referred to as a "wireless resource information signal sequence") for transmitting one or more wireless resource pieces of information, according to one or more wireless resource pieces of information received from the wireless protocol control unit 310, at a timing instructed by the wireless protocol control unit 310, and send it to the baseband signal generation unit 430.

[0127] The individual transmission signal generation unit 420 is configured to generate a signal for transmitting an individual signal (hereinafter also referred to as the "individual transmission signal sequence") according to the individual signal (communication data or control data) received from the wireless protocol control unit 310 at a timing instructed by the wireless protocol control unit 310, and send it to the baseband signal generation unit 430.

[0128] The baseband signal generation unit 330 or 430 is configured to generate a continuous baseband signal representing the amplitude and phase of the signals for transmitting a reference signal sequence received from the reference signal generation unit 320, a radio resource information signal sequence received from the radio resource information signal generation unit 360, or an individual transmission signal sequence received from the individual transmission signal generation unit 420. Furthermore, if the common signal transmission antenna 350 or the individual signal transmission / reception antenna 450 is an array antenna, the first radio device 20 may be configured to set the phase of each antenna element in the baseband signal generation unit 330 or 430 so that a predetermined directivity is formed in the common signal transmission antenna 350 or the individual signal transmission / reception antenna 450. The common signal transmission antenna 350 and the individual signal transmission / reception antenna 450 may also be antennas 910.

[0129] The radio units 340 and 440 are configured to receive a continuous baseband signal from the baseband signal generation units 330 and 430, generate radio frequency signals with corresponding amplitude and phase, and supply them to the antennas (common signal transmitting antenna 350 and individual signal transmitting / receiving antennas 450). If the common signal transmitting antenna 350 or the individual signal transmitting / receiving antennas 450 is an array antenna, the radio units 340 and 440 may also set the phase of each antenna element so that a predetermined directivity is formed in the common signal transmitting antenna 350 or the individual signal transmitting / receiving antennas 450. The radio unit 440 is also configured to generate a baseband signal corresponding to the amplitude and phase of the radio signal received by the individual signal transmitting / receiving antenna 450 and send it to the baseband signal processing unit 460. The radio units 340 and 440 may also be RF circuits 920.

[0130] The baseband signal processing unit 460 is configured to obtain a sequence (hereinafter also referred to as the "received individual signal sequence") containing individual signals (communication data and control data) from the baseband signal corresponding to the radio frequency signal received by the individual signal transmitting and receiving antenna 450, and send it to the received individual signal processing unit 470.

[0131] The received individual signal processing unit 470 is configured to extract individual signals from the received individual signal sequence obtained from the baseband signal processing unit 460 and send them to the radio protocol control unit 310. The received individual signal processing unit 470 may also be configured to send to the radio protocol control unit 310 information regarding the position on the radio frame in which the individual signal was contained.

[0132] <<<Second Wireless Device>>> Figure 5 shows a processing block in which the second wireless device 10 receives a common signal (reference signal and wireless resource information signal) transmitted from the common signal transmitting antenna 350 of the first wireless device 20, determines the wireless resources for transmitting a feedback signal to the first wireless device 20, and transmits the feedback signal. The second wireless device 10 has other processing blocks and a power supply unit, but these are not directly necessary for explaining this embodiment and are therefore omitted from the illustration.

[0133] The processing to be performed by the baseband signal generation unit 630, the individual transmission signal generation unit 620, and the radio unit 540 among the processing blocks of the second radio device 10 shown in Figure 5 is generally the same as that of the processing blocks with the same names in the first radio device 20. Also, similar to the first radio device 20, the processing blocks other than the radio unit 540 can be realized by hardware such as a processor 930 (for example, a CPU) and memory 960, and software that performs the respective calculations.

[0134] The baseband signal processing unit 560 of the second radio device is configured to generate a received signal sequence corresponding to a reference signal sequence from a baseband signal corresponding to the amplitude and phase of the received radio signal and send it to a reference signal extraction unit 570. Furthermore, it is configured to generate a received signal sequence corresponding to a radio resource information signal sequence from that baseband signal and send it to a radio resource information extraction unit 580. Furthermore, it is configured to generate a received individual signal sequence corresponding to individual signals (communication data and control data) transmitted from the individual signal transmitting / receiving antenna of the first radio device 20 from that baseband signal and send it to a received individual signal processing unit 670.

[0135] Let the [transmission] reference signal sequence corresponding to each reference signal be A(n). ｋ If the received reference signal sequence corresponding to the [transmission] reference signal sequence is represented by the following mathematical formula (5).

[0136] z(n) is the component of other signals and the noise component that were transmitted at the same time and the same frequency as the reference signal. ｋ α, θ are the amplitude component and the phase component of the transfer coefficient in the path from the output of the baseband signal generation unit of the first radio device to the baseband signal processing unit of the second radio device. If the first radio device and the second radio device are properly calibrated, α = 1, and θ can be considered as the phase component of the propagation path constant from the common signal transmission antenna 350 of the first radio device to the reception antenna of the second radio device. ｋ θ ｋ α, θ are the amplitude component and the phase component of the transfer coefficient in the path from the output of the baseband signal generation unit of the first radio device to the baseband signal processing unit of the second radio device. If the first radio device and the second radio device are properly calibrated, α = 1, and θ can be considered as the phase component of the propagation path constant from the common signal transmission antenna 350 of the first radio device to the reception antenna of the second radio device. ｋ α = 1, θ ｋ can be considered as the phase component of the propagation path constant from the common signal transmission antenna 350 of the first radio device to the reception antenna of the second radio device.

[0137] The reception individual signal processing unit 670 provided in the second radio device is configured to extract an individual signal (for example, control data) from the reception individual signal sequence obtained from the baseband signal processing unit and send it to the radio protocol control unit 510.

[0138] The reference signal extraction unit 570 provided in the second radio device is configured to detect the presence of the reference signal from the received signal sequence r(n) corresponding to the reference signal sequence sent from the baseband signal processing unit 560 and notify the radio protocol control unit 510. The operation of extracting the component R of the reference signal can be performed by the sum of products of r(n) in the mathematical formula (5) and the complex conjugate of the reference signal sequence as shown in the following mathematical formula (6). ｋ The operation of extracting the component R of the reference signal can be performed by the sum of products of r(n) in the mathematical formula (5) and the complex conjugate of the reference signal sequence as shown in the following mathematical formula (6). ｋ The operation of extracting the component R of the reference signal can be performed by the sum of products of r(n) in the mathematical formula (5) and the complex conjugate of the reference signal sequence as shown in the following mathematical formula (6). ｋ (n) and the complex conjugate of the reference signal sequence.

[0139] Here, N is the sequence length of the reference signal sequence. <l ｋ Including other reference signals that were transmitted simultaneously by a reference signal sequence different from A(n), the components of other signals and the noise component that were transmitted at the same time and the same frequency as the reference signal are ｋSince the correlation with (n) is considered to be low or nonexistent, Z in equation (6) ｋ is, e ｊθｋ This number is significantly smaller than 1, which is the magnitude of the signal. If the reference signal is not transmitted, equation (6) becomes Z ｋ Only R ｋ The result is a number much smaller than 1. Therefore, R calculated by setting a predetermined threshold is ｋ If the value is greater than that, it can be determined that the presence of the reference signal has been detected.

[0140] The second radio device may attempt to receive / decode multiple common signals transmitted in multiple common signal transmission resources, or it may attempt to receive / decode multiple reference signals included in each of those common signals, or it may measure multiple quantities measured from each of those reference signals. The quantities measured are, for example, R ｋ The first radio device may determine that the first reference signal / common signal corresponds to one or more measured quantities that exceed a threshold among a plurality of measured quantities, and may be an absolute value or a relative value. The second radio device may determine that the first reference signal / common signal corresponds to one or more measured quantities that are within a specific range among the relative values ​​of a plurality of measured quantities, and may determine that the first reference signal / common signal corresponds to one or more measured quantities that are outside a specific range among the relative values ​​of a plurality of measured quantities, and may determine that the first reference signal / common signal corresponds to one or more measured quantities that are outside a specific range among the relative values ​​of a plurality of measured quantities.

[0141] The wireless protocol control unit 510 of the second wireless device is configured to receive one or more pieces of wireless resource information extracted by the wireless resource information extraction unit 660 at the time it is notified by the reference signal extraction unit that a reference signal has been detected, and to hold these one or more pieces of wireless resource information as one or more pieces of wireless resource information corresponding to the reference signal. The wireless resource information indicates a wireless resource for transmitting a feedback signal to the first wireless device that transmitted the reference signal, and the wireless protocol control unit 510 is configured to select and determine a wireless resource for transmitting a feedback signal to the first wireless device from among the one or more pieces of wireless resource information it holds.

[0142] If the second radio device receives only one common signal (i.e., the number of common signals detected / received by the second radio device is less than a specific number of 2), the second radio device may select multiple radio resource information, including one or all of the multiple radio resource information within that common signal. This selection of one or more radio resource information may be based on priority information indicating which radio resource is preferentially used for transmitting feedback signals, may be random, or may depend on the implementation of the second radio device. Priority information may be defined in the specification or may be set / instructed / notified by the first radio device. The radio resource information signal may include priority information. Priority information may refer to the first radio resource information among the multiple radio resource information included in the radio resource information signal, or to a radio resource information having a specific value / index among the multiple radio resource information included in the radio resource information signal.

[0143] The second radio device can receive multiple common signals (multiple pairs of reference signals and radio resource information signals). In that case (when the number of common signals detected / received by the second radio device is a specific number of 2 or more), the radio protocol control unit 510 is configured to hold multiple radio resource information signals corresponding to multiple different reference signals, detect the presence or absence of identical radio resource information among the multiple radio resource information signals, and if the multiple radio resource information signals contain identical radio resource information, determine the radio resource indicated in that radio resource information as the radio resource for transmitting a feedback signal to the first radio device.

[0144] The wireless protocol control unit 510 of the second wireless device is also configured to send an instruction to the transmission individual signal generation unit 620 to generate a feedback signal at the timing corresponding to the determined wireless resource, thereby enabling the feedback signal to be transmitted to the first wireless device using the determined wireless resource. If multiple wireless resources are selected, the wireless protocol control unit 510 may be configured to send an instruction to the transmission individual signal generation unit 620 so that a feedback signal is transmitted to the first wireless device using each of the selected wireless resources.

[0145] The first radio device may transmit a common signal using different directivity at multiple different times / frequencies.

[0146] The second radio device may report / notify its own position by transmitting a feedback signal. The first radio device may determine the location from which the feedback signal was transmitted (the location of the second radio device) based on the radio resource (time / frequency) on which the feedback signal was received. For example, the first radio device may specify the location of the second radio device as a spatial range corresponding to its radio resource, or a sub-range within the spatial range corresponding to its radio resource.

[0147] Since the following embodiments can be adapted from some of the configurations and operations of Embodiment 1, the differences from Embodiment 1 will be explained primarily.

[0148] <<Embodiment 2>> The first radio device in Embodiment 2 can be mounted on an artificial satellite. In the case of an artificial satellite orbiting the Earth at an altitude of 600 km, the artificial satellite will be in the field of view at an elevation angle of 30° or more within a 1600 km diameter area on the ground centered directly below the satellite, so the first radio device can have this area as its service area. The first radio device mounted on an artificial satellite may be equipped with a directional antenna capable of forming multiple different directivity patterns directed towards multiple different geographical areas on the ground within the service area. The directivity of the common signal transmitting antenna, which transmits a common signal widely within the service area, can be set to point towards a wider geographical area than the directivity of the individual signal transmitting and receiving antenna, which only needs to point towards the direction of the connected second radio device. For example, the geographical area to which the directivity of the common signal transmitting antenna points can be set to an area with a diameter of approximately 150 km on the ground, and the partial area to which the directivity of the individual signal transmitting and receiving antenna points can be set to an area with a diameter of approximately 50 km on the ground. In this case, the spatial range to which the directivity of the common signal transmitting antenna is directed can be subdivided into seven sub-ranges, each with a diameter of approximately 50 km, as shown in Figure 8. Each sub-range can correspond to the spatial range to which the directivity of the individual signal transmitting and receiving antennas is directed.

[0149] As shown in Figure 9, the first wireless device subdivides its service area according to the partial range covered by the directivity of individual signal transmitting and receiving antennas, setting seven partial ranges centered on the partial ranges labeled 0a, 0b, and 0c in the figure as spatial ranges, and can transmit a common signal using a common signal transmitting antenna that uses directivity facing these spatial ranges.

[0150] When the second radio device is located within the specific sub-ranges labeled 0a, 0b, and 0c in the figure, it best receives the common signal transmitted by a common signal transmitting antenna whose directivity is set to center on that specific sub-range, and does not receive the common signal transmitted by a common signal transmitting antenna whose directivity is set to center on a non-specific sub-range outside of that specific sub-range. On the other hand, when the second radio device is located within a non-specific sub-range (i.e., a sub-range other than those labeled 0a, 0b, and 0c in Figure 9, for example, sub-ranges 1 to 13), it receives the three common signals transmitted by a common signal transmitting antenna whose directivity is set to center on the specific sub-ranges 0a, 0b, and 0c adjacent to that non-specific sub-range.

[0151] The first radio device configures the radio resources that the second radio device uses to transmit feedback signals for an unspecified subrange. Multiple different radio resources (multiple indices) are associated with all subranges included in multiple spatial ranges, which include the said unspecified subrange, and the radio resource (index) corresponding to the said unspecified subrange is determined to be the only radio resource (index) among those multiple radio resources (multiple indices).

[0152] In wireless resource information, the wireless resource used to transmit feedback signals may be indicated by an index (or associated with an index). The index may directly indicate the location of the wireless resource on the wireless frame, or it may indicate its relative location from the wireless resource from which the common signal is transmitted. In the latter case, if the wireless resource from which the common signal is transmitted is different, the same wireless resource may be indicated even if the index itself is different. The numbers 1 to 15 written in each sub-range of Figure 9 are examples of indices that indicate a specific location on the wireless frame.

[0153] The common signal transmitted by the first radio device using a common signal transmitting antenna may include a radio resource information signal. The radio resource information signal may include multiple indices corresponding to multiple sub-ranges included in the spatial range to which the directivity formed when transmitting the common signal is directed. For example, as shown in the example in Figure 10, radio resource information signal #1 including the indices 0a, 1, 2, 3, 4, 5, 6 may be transmitted toward spatial range #1 to which the directivity #1 of the common signal transmitting antenna is directed, radio resource information signal #2 including the indices 0b, 5, 6, 10, 11, 12, 13 may be transmitted toward spatial range #2 to which the directivity #2 of the common signal transmitting antenna is directed, and radio resource information signal #3 including the indices 0c, 4, 5, 7, 8, 9, 10 may be transmitted toward spatial range #3 to which the directivity #3 of the common signal transmitting antenna is directed.

[0154] A second radio device that receives only one common signal recognizes that it is located in a specific sub-range at the center of the spatial range towards which the transmitted directivity is directed, and transmits a feedback signal to the first radio device in the radio resource corresponding to index 0a, 0b, or 0c. This operation allows the second radio device located in the specific sub-range to appropriately identify / recognize and report / notify that specific sub-range. The radio resource information corresponding to the specific sub-range may be the first radio resource information among multiple radio resource information included in the radio resource information signal, or it may be determined based on priority information.

[0155] When the second radio device detects / receives three common signals (when the number of common signals detected / received by the second radio device is three or more), it recognizes that it is located in an unspecified sub-range where the spatial ranges toward which the directivity of the three common signals is directed overlap, and detects the presence or absence of common radio resource information in the three radio resource information signals. If common radio resource information is detected, the second radio device transmits a feedback signal to the first radio device for the radio resource indicated in the detected common radio resource information. In Figure 9, the second radio device located in the unspecified sub-range where the spatial ranges #1, #2, and #3 toward which the directivity of the common signal transmitting antenna is directed overlap receives the three common signals transmitted toward those three spatial ranges, detects index 5, which is included in all three common signals, as a common radio resource, and transmits a feedback signal to the first radio device for the radio resource corresponding to index 5. Through this operation, the second radio device located in the unspecified sub-range can appropriately identify / recognize and report / notify that unspecified sub-range.

[0156] A second radio device, upon detecting / receiving two common signals (when the number of common signals detected / received by the second radio device is less than a specific number of 3), may select one radio resource from among multiple radio resource pieces in the common signals, or it may select one radio resource piece common to multiple radio resource pieces. This one radio resource piece may be selected according to priority information indicating the radio resource to be preferentially used for transmitting feedback signals, may be selected randomly, or may depend on the implementation of the second radio device.

[0157] Priority information may be defined in the specifications or set / instructed / notified by the first radio device. The radio resource information signal may include priority information. Priority information may refer to the first radio resource information among multiple radio resource information included in the radio resource information signal, or to the radio resource information having the lowest value / index among multiple radio resource information included in the radio resource information signal.

[0158] The first radio device receives feedback signals from the second radio device by forming a directivity pointing towards a specific sub-range within the radio resources set for each sub-range. Upon receiving the feedback signal, the first radio device may control its antenna for transmitting and receiving individual signals (communication data and control data) to set that directivity when transmitting and receiving individual signals (communication data and control data) with the second radio device thereafter. If the feedback signal is a signal requesting connection from the second radio device, which is not currently connected to the first radio device, the initial connection process between the second radio device and the first radio device may be initiated.

[0159] <<Embodiment 3>> The first wireless device according to Embodiment 3 may form multiple directivity points toward multiple different spatial ranges in a common signal transmitting antenna, and use each directivity to transmit an index information signal relating to an index indicating a subdivided subrange of the corresponding spatial range. The index information signal may include multiple indices indicating multiple subranges.

[0160] The first wireless device may transmit an index information signal instead of the wireless resource information signal in Embodiment 1 / Embodiment 2. The common signal may include a reference signal and an index information signal.

[0161] If there is overlap between multiple spatial ranges, the index corresponding to the overlapping subrange may be the same index.

[0162] When the second radio device receives a single common signal, it may select one index from among several indices contained in that common signal and transmit a feedback signal containing that index to the first radio device. This operation allows the second radio device, located in a specific subrange, to appropriately identify / recognize and report / notify that specific subrange. The index corresponding to the specific subrange may be the first index among several indices contained in the index information signal, or it may be determined based on priority information.

[0163] When the second radio device receives multiple common signals (multiple reference signals and multiple index information signals), it may detect the presence or absence of identical indices among the multiple index information signals contained in each of the multiple common signals, and if identical indices are found, it may transmit a feedback signal containing those indices to the first radio device.

[0164] The index information signal may include the same index as in Embodiment 2. For example, as shown in the example in Figure 11, an index information signal #1 including the indices 0a, 1, 2, 3, 4, 5, 6 may be transmitted toward spatial range #1 to which the directivity #1 of the common signal transmitting antenna is directed; an index information signal #2 including the indices 0b, 5, 6, 10, 11, 12, 13 may be transmitted toward spatial range #2 to which the directivity #2 of the common signal transmitting antenna is directed; and an index information signal #3 including the indices 0c, 4, 5, 7, 8, 9, 10 may be transmitted toward spatial range #3 to which the directivity #3 of the common signal transmitting antenna is directed.

[0165] When the second radio device detects / receives three common signals (when the number of common signals detected / received by the second radio device is three or more), it recognizes that it is located in an unspecified sub-range where the spatial ranges toward which the directivity of the three common signals is directed overlap, and detects the presence or absence of a common index in the three index information signals. If a common index is detected, the second radio device transmits a feedback signal indicating the detected common index. In Figure 9, the second radio device located in the unspecified sub-range where the spatial ranges #1, #2, and #3 toward which the directivity of the common signal transmitting antenna is directed overlap receives the three common signals transmitted toward those three spatial ranges, detects index 5 which is commonly included in the three common signals as the common index, and transmits a feedback signal indicating index 5 to the first radio device. Through this operation, the second radio device located in the unspecified sub-range can appropriately identify / recognize and report / notify that unspecified sub-range.

[0166] A second radio device, upon detecting / receiving two common signals (when the number of common signals detected / received by the second radio device is less than a specific number of 3), may select one index from among several indices within those common signals. This index may be selected according to priority information indicating preferred indices, randomly, or depending on the implementation of the second radio device.

[0167] Priority information may be defined in the specifications or set / instructed / notified by the first radio device. The index information signal may include priority information. Priority information may refer to the first index among multiple indices included in the index signal, or to the index with the lowest value among multiple indices included in the index signal.

[0168] The second radio device may report / notify its own position by transmitting a feedback signal. The first radio device may identify the location from which the feedback signal was transmitted (the position of the second radio device) based on the index indicated by the feedback signal. For example, the first radio device may identify the location of the second radio device as a spatial range corresponding to that index, or as a sub-range within the spatial range corresponding to that index.

[0169] A radio resource for transmitting feedback signals may be defined in the specification or configured / instructed by the first radio device. The radio resource may be associated with an index. The second radio device may transmit a PUCCH / PUSCH containing the feedback signal. The radio resource may be configured / instructed / scheduled by RRC IE / DCI.

[0170] The first radio device receives a feedback signal from the second radio device, recognizes that the second radio device is located in an overlapping sub-range among several sub-ranges according to the index included in the feedback, and can then control the directivity of the individual signal transmission / reception antenna used when transmitting and receiving individual signals (communication data and control data) with the second radio device.

[0171] <<Embodiment 4>> This embodiment relates to the attributes of a feedback signal. The feedback signal in this embodiment may be applied to at least one of Embodiments 1 to 3.

[0172] In this embodiment, the first wireless device may, in place of (or in addition to) the radio resource information or index information provided by the first wireless device to the second wireless device in embodiments 1 to 3, provide the second wireless device with feedback signal attribute information for determining the attributes of the feedback signal. The first wireless device provides the second wireless device with information for determining the attributes of the feedback signal, and detailed feedback signal attributes may be defined in the specifications or maintained by the second wireless device. When a signal modulated by a pseudo-random sequence modulates the radio carrier is used as the feedback signal, the feedback signal attribute information may also be information for determining the pseudo-random sequence. For example, the pseudo-random sequence may be a Gold sequence, a Walsh-Hadamard sequence, or a Zadoff-Chu sequence (low PAPR sequence). For example, the attributes may include at least one of the following: the initial value of the pseudo-random sequence generator, the sequence group number, the sequence number, and the [initial] cyclic shift index. The attributes may also be the phase difference, amplitude difference, or combination thereof between the feedback signal and the reference signal transmitted attached to the feedback signal.

[0173] The common signal may include a reference signal and a feedback signal attribute information signal. The feedback signal attribute information signal may include one or more feedback signal attribute information. When the second radio device receives multiple common signals (multiple reference signals and multiple feedback signal attribute information signals), it detects the presence or absence of identical feedback signal attribute information from among the multiple feedback signal attribute information signals corresponding to each of the multiple different reference signals. If identical feedback signal attribute information is found, it determines the attributes of the feedback signal according to that feedback signal attribute information and transmits the feedback signal having the determined attributes to the first radio device. The first radio device attempts to detect a feedback signal having predetermined attributes in the signal received by an antenna with directivity set to correspond to the area where the second radio device may be located, as well as its azimuth and elevation angles. The detected feedback signal allows the first radio device to identify the area where the second radio device is located, as well as its azimuth and elevation angles.

[0174] <<Embodiment 5>> This embodiment relates to the content of a feedback signal. The feedback signal may include a field (index [information] field) for transmitting information relating to the number of reference signals (common signals) received by the second radio device, information relating to the received power of those reference signals, or index information (Embodiment 3) relating to an index indicating a subdivided sub-range of a spatial range. The feedback signal in this embodiment may be applied to at least one of Embodiments 1 to 4.

[0175] In this embodiment, the feedback signal for feedback from the second radio device to the first radio device may include a field for transmitting at least one of the following: information regarding the number of reference signals received by the second radio device and information regarding the received power of those reference signals. The position and number of bits of the field in the feedback signal, the method of encoding the information to be fed back into a bit sequence that fits in the field, etc., can be predetermined (they may be defined in the specifications or set). Multiple methods for handling / interpreting the field can be predetermined, and the first radio device may provide the second radio device with information on how to handle the field as control data (individual signal) so that the second radio device can select one of these multiple methods to perform the feedback. The second radio device encodes the number of reference signals received from the first radio device and the received power of those reference signals according to a predetermined method, or according to how to handle the field indicated by the control data (individual signal) received from the first radio device, stores the encoding result in a predetermined position in the field, and transmits a feedback signal including that field. The first radio device can determine the region where the second radio device is located, or its azimuth and elevation angles, from the field information in the feedback signal received from the second radio device.

[0176] <<Supplement>> The common signal may include a reference signal and system information, and the system information may include a radio resource information signal. The feedback signal may use a random access channel. For example, a second radio device that is not connected to the first radio device (in an unconnected state, e.g., RRC_IDLE state or RRC_INACTIVE state) may perform initial access to the first radio device by synchronizing with the first radio device based on the reference signal and performing a random access procedure using radio resources and feedback signals based on the system information. The second radio device may perform initial access in particular according to Embodiment 1 / Embodiment 2 / Embodiment 4.

[0177] Radio resources for transmitting feedback signals may be configured / instructed / scheduled. For example, a second radio device connected to a first radio device (in a connected state, e.g., RRC_CONNECTED state) may use its radio resources to report / notify the first radio device of its position by transmitting a feedback signal indicating an index corresponding to a subrange. The second radio device may report / notify its position in particular according to Embodiment 3 / Embodiment 4 / Embodiment 5. For example, if the second radio device moves from its current spatial range / subrange to another spatial range / subrange, it may report / notify its position by a feedback signal.

[0178] <Notes> The following inventions are added with respect to one embodiment of the present disclosure. [Note 1] A second wireless device comprising: a receiving unit that receives one or more first signals and receives one or more second signals based on the one or more first signals; a processing unit that determines one wireless resource from a plurality of wireless resources indicated by the one or more second signals; and a transmitting unit that transmits a feedback signal at the one wireless resource, wherein if the one or more first signals are two or more first signals and the one or more second signals are two or more second signals, the processing unit determines the wireless resources that are overlappingly indicated by the two or more second signals as the one wireless resource. [Note 2] The second wireless device according to Note 1, wherein one of the one or more first signals is associated with a spatial range in which the second wireless device may exist, and the one wireless resource is associated with a part of the single spatial range. [Note 3] The second wireless device according to Note 1 or Note 2, wherein if the number of the one or more first signals is less than a specific number, the processing unit determines the one wireless resource from the plurality of wireless resources based on priority information. [Note 4] The second radio device according to any one of Notes 1 to 3, wherein, when the second radio device is not connected to the first radio device, the receiving unit receives one or more first signals from the first radio device and receives one or more second signals from the first radio device. [Note 5] The first radio device having: a transmitting unit that transmits a plurality of first signals and a plurality of second signals based on the plurality of first signals to each of a plurality of spatial ranges in which the second radio device may exist; a receiving unit that receives a feedback signal in one of a plurality of radio resources indicated in the plurality of second signals and associated with a part of the plurality of spatial ranges; and a processing unit that identifies the location of the second radio device that transmitted the feedback signal based on the one radio resource.[Note 6] A wireless communication method for a second wireless device, comprising the steps of: receiving one or more first signals and receiving one or more second signals based on the one or more first signals; determining one radio resource from a plurality of radio resources indicated by the one or more second signals; and transmitting a feedback signal at the one radio resource, wherein if the one or more first signals are two or more first signals and the one or more second signals are two or more second signals, the second wireless device determines the radio resources that are overlappingly indicated by the two or more second signals as the one radio resource. [Note 7] A wireless communication system comprising the first wireless device described in Note 5 and the second wireless device described in Note 1. [Supplement] The plurality of first signals may be, for example, a plurality of reference signals each included in a plurality of common signals transmitted by the first wireless device. The plurality of second signals may be, for example, a plurality of radio resource information signals each included in a plurality of common signals transmitted by the first wireless device. The one or more first signals may be, for example, a plurality of reference signals each included in a plurality of common signals detected / received by the second wireless device. One or more second signals may be, for example, multiple radio resource information signals included in multiple common signals detected / received by a second radio device.

[0179] <Notes> The following inventions are added with respect to one embodiment of the present disclosure. [Note 1] A second wireless device comprising: a receiving unit that receives one or more first signals and receives one or more second signals based on the one or more first signals; a processing unit that determines one index from a plurality of indices indicated in the one or more second signals; and a transmitting unit that transmits a feedback signal indicating the one index, wherein if the one or more first signals are two or more first signals and the one or more second signals are two or more second signals, the processing unit determines the index that is overlappingly indicated by the two or more second signals as the one index. [Note 2] The second wireless device according to Note 1, wherein one of the one or more first signals is associated with a spatial range in which the second wireless device may exist, and the one index is associated with a part of the spatial range. [Note 3] The second wireless device according to Note 1 or Note 2, wherein if the number of the one or more first signals is less than a specific number, the processing unit determines the one index from the plurality of indices based on priority information. [Note 4] The second radio device according to any one of Notes 1 to 3, wherein, when the second radio device is connected to the first radio device, the receiving unit receives one or more first signals from the first radio device and receives one or more second signals from the first radio device. [Note 5] The first radio device having: a transmitting unit that transmits a plurality of first signals and a plurality of second signals based on the plurality of first signals to each of a plurality of spatial ranges in which the second radio device may exist; a receiving unit that receives a feedback signal indicating one index among a plurality of indices shown in the plurality of second signals and associated with a part of the plurality of spatial ranges; and a processing unit that identifies the location of the second radio device that transmitted the feedback signal based on the one index.[Note 6] A wireless communication method for a second wireless device, comprising the steps of: receiving one or more first signals and receiving one or more second signals based on the one or more first signals; determining one index from a plurality of indices indicated in the one or more second signals; and transmitting a feedback signal indicating the one index, wherein if the one or more first signals are two or more first signals and the one or more second signals are two or more second signals, the second wireless device determines the index that is overlappingly indicated by the two or more second signals as the one index. [Note 7] A wireless communication system comprising the first wireless device described in Note 5 and the second wireless device described in Note 1. [Supplement] The plurality of first signals may be, for example, a plurality of reference signals each included in a plurality of common signals transmitted by the first wireless device. The plurality of second signals may be, for example, a plurality of index information signals each included in a plurality of common signals transmitted by the first wireless device. The one or more first signals may be, for example, a plurality of reference signals each included in a plurality of common signals detected / received by the second wireless device. One or more second signals may be, for example, multiple index information signals included in multiple common signals detected / received by a second radio device.

[0180] <Modification> Terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings.

[0181] In this disclosure, terms such as apparatus, circuit, device, section, and unit are interchangeable.

[0182] The information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or corresponding other information. For example, wireless resources may be indicated by a given index.

[0183] The names used for parameters and other elements in this disclosure are not restrictive in any way. Furthermore, mathematical formulas and other elements that use these parameters may differ from those explicitly disclosed in this disclosure.

[0184] The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0185] Input and output information and signals may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information and signals may be overwritten, updated, or appended to. Output information and signals may be deleted. Input information and signals may be transmitted to other devices.

[0186] Any information described in this disclosure (e.g., variables, constants, parameters) may be notified from any first device (e.g., UE / BS) to any second device (e.g., BS / UE), even if not specifically stated in the embodiments described above. Notification of any information may be interpreted as notification of information indicating / specifying (or relating to) the value of such any information.

[0187] In this disclosure, the words “notify,” “request,” “activate,” “deactivate,” “indicate,” “select,” “configure,” “update,” and “determine” may be interpreted as interchangeable.

[0188] In this disclosure, the terms "support," "control / operate / use," and "control / operate / are available" may be interpreted as interchangeable.

[0189] In this disclosure, notification of information is not limited to the manner / embodiments described herein and may be carried out by other means. For example, notification of information in this disclosure may be carried out by radio access-related signaling, RAN-related signaling, core network-related signaling, other signals, or a combination thereof. In this disclosure, signaling, messages, parameters, fields, information elements (IEs), settings, etc., may be interpreted interchangeably.

[0190] Wireless access-related signaling may include signaling related to wireless access (wireless interface) between UE-RAN, and may also fall under Access Stratum (AS) signaling. Wireless access-related signaling may also include physical layer signaling, higher layer signaling, etc.

[0191] Physical layer signaling may include, for example, Downlink Control Information (DCI) and Uplink Control Information (UCI). Upper layer signaling may include, for example, Radio Resource Control (RRC) signaling and Medium Access Control (MAC) signaling.

[0192] RRC signaling may include broadcast information (e.g., Master Information Block (MIB), System Information Block (SIB)). MAC signaling may include MAC Control Element (MAC CE), MAC Protocol Data Unit (MAC PDU), etc.

[0193] RAN-related signaling may include signaling for control between RANs, such as Xn Application Protocol (XnAP) signaling.

[0194] Core network-related signaling may include signaling for control between UE and CN, such as Non-Access Stratum (NAS) signaling. Core network-related signaling may also include signaling for control between CN and CN, such as HyperText Transfer Protocol (HTTP) messages.

[0195] Furthermore, notification of the specified information (for example, notification that "X is the case") is not limited to explicit notification, but may also be made implicitly (for example, by not notifying the specified information or by notifying other information).

[0196] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0197] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or Digital Subscriber Line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0198] The terms “system” and “network” as used in this disclosure may be used interchangeably. “Network” may also mean the equipment included in the network (e.g., base stations).

[0199] In this disclosure, terms such as “precoding,” “precoder,” “spatial domain filter,” “transmit power,” “phase rotation,” “layer,” “rank,” “resource,” “resource set,” “beam,” “antenna,” “antenna element,” “antenna port,” “panel,” and “UE panel” may be used interchangeably.

[0200] In this disclosure, terms such as "Base Station (BS)", "Radio Base Station", "Relay Station", "Fixed Station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "Radio Access Network (RAN)", "Access Point", "Transmission Point (TP)", "Reception Point (RP)", "Transmission / Reception Point (TRP)", "Panel", "[Super / Macro / Small / Femto / Pico] Cell", "Sector", "Cell Group", "Carrier", and "Component Carrier" may be used interchangeably.

[0201] In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform a control / operation based on said information.

[0202] In this disclosure, terms such as "Mobile Station (MS)," "Mobile Node," "User Terminal," "Terminal Station," "Terminal," and "User Equipment (UE)" may be used interchangeably.

[0203] Furthermore, BS / UE may also be classified as a Road-Side Unit (RSU).

[0204] Any device in this disclosure may also be called a server, device, transmitter, receiver, wireless communication device, information processing device, etc., and these terms may be interchangeable. Any device in this disclosure may be a device mounted on a moving object, a device contained within a moving object (held by a person riding in the moving object), or the moving object itself. Such moving objects include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and items mounted on them. Such moving objects may also be autonomous / autonomous. In this disclosure, a moving object may also be interchangeable with a non-moving object (for example, a non-moving object that a person can ride in).

[0205] Each aspect / embodiment described in this disclosure may be used individually, in combination, or switched between during execution. Furthermore, the processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described in this disclosure may be rearranged in order of steps, or some steps may be omitted, as long as they are consistent. For example, the methods described in this disclosure present various step elements using exemplary order and are not limited to the specific order presented.

[0206] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0207] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, the references to the first and second elements do not imply that only two elements may be employed or that the first element must precede the second element in any way.

[0208] As used in this disclosure, the terms “connected,” “coupled,” and any variations thereof mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. The coupling or connection between elements may be via at least one of wired and wireless connections.

[0209] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0210] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0211] In this disclosure, if articles are added by translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0212] In this disclosure, words such as "decision," "judgment," "determination," "selection," "specification," "calculation," "calculation," "processing," "derivation," "search," "confirmation," "assumption," and "expectation" may be interpreted as interchangeable.

[0213] In this disclosure, terms such as "less than or equal to," "less than," "greater than or equal to," "more than," and "equal to" may be interpreted interchangeably. In addition, in this disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "early," "slow," "wide," and "narrow" may be interpreted interchangeably, not limited to the positive, comparative, and superlative degrees. Furthermore, in this disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "early," "slow," "wide," and "narrow" may be interpreted interchangeably, not limited to the positive, comparative, and superlative degrees, by adding "i-th" (where i is any integer) to the expression (for example, "highest" may be interpreted interchangeably as "i-th highest").

[0214] In this disclosure, "of," "for," "regarding," "related to," and "associated with" may be interpreted as being interchangeable.

[0215] Although the invention described herein has been explained in detail above, it will be clear to those skilled in the art that the invention described herein is not limited to the embodiments described herein. The descriptions herein are illustrative and not intended to be restrictive in any way to the invention described herein.

[0216] This application is based on Japanese Patent Application No. 2025-018145, filed on February 6, 2025. All of its contents are included herein.

Claims

1. A second wireless device comprising: a receiving unit that receives one or more first signals and receives one or more second signals based on the one or more first signals; a processing unit that determines one index from a plurality of indices indicated in the one or more second signals; and a transmitting unit that transmits a feedback signal indicating the one index, wherein if the one or more first signals are two or more first signals and the one or more second signals are two or more second signals, the processing unit determines the index that is overlappingly indicated by the two or more second signals as the one index.

2. The second radio device according to claim 1, wherein one of the one or more first signals is associated with a spatial range in which the second radio device may exist, and one index is associated with a portion of the spatial range.

3. The second wireless device according to claim 1, wherein if the number of one or more first signals is less than a specific number, the processing unit determines one index from the plurality of indices based on priority information.

4. The second wireless device according to claim 1, wherein, when the second wireless device is connected to the first wireless device, the receiving unit receives one or more first signals from the first wireless device and receives one or more second signals from the first wireless device.

5. A first wireless device comprising: a transmitting unit that transmits a plurality of first signals and a plurality of second signals based on the plurality of first signals to each of a plurality of spatial ranges in which a second wireless device may exist; a receiving unit that receives a feedback signal indicating one index among a plurality of indices shown in the plurality of second signals and associated with a part of the plurality of spatial ranges; and a processing unit that identifies the location of the second wireless device that transmitted the feedback signal based on the one index.

6. A wireless communication method for a second wireless device, comprising the steps of: receiving one or more first signals and receiving one or more second signals based on the one or more first signals; determining one index from a plurality of indices indicated in the one or more second signals; and transmitting a feedback signal indicating the one index, wherein if the one or more first signals are two or more first signals and the one or more second signals are two or more second signals, the second wireless device determines the index that is overlappingly indicated by the two or more second signals as the one index.

7. A wireless communication system comprising the first wireless device described in claim 5 and the second wireless device described in claim 1.

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