Communication device, communication method, and communication system

Abstract

A communication device according to the present invention performs wireless communication using a plurality of channels. The communication device includes a generating unit that generates a plurality of bitstreams of different contents, by applying predetermined encoding processing based on a predetermined error correction encoding format to a transmission data stream, and a distributing unit that distributes the plurality of bitstreams to the plurality of channels.

Description

Technical Field

[0001] The present disclosure relates to a communication device, a communication method, and a communication system.

Background Art

[0002] Communications with high communication performance (e.g., high reliability, low latency, and high frequency utilization efficiency) that can support various use cases are required. For example, in 5G, which is the next-generation communication standard, URLLC (Ultra-Reliable and Low Latency Communication), which means ultra-high-reliability and low-latency communication, is defined to support various use cases. In URLLC, a technique called Packet Duplication, which achieves high reliability by using multiple independent channels, may be used.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The introduction of one technology may result in a certain improvement in one aspect of communication performance, while significantly degrading another. For example, in the packet duplication example mentioned above, while communication reliability improves, the transmission of the same data over multiple channels significantly reduces frequency utilization efficiency. In this case, it cannot necessarily be said that high communication performance has been achieved.

[0005] Therefore, this disclosure proposes a communication device, a communication method, and a communication system that can achieve high communication performance.

[0006] It should be noted that the above-mentioned problems or objectives are merely one of several problems or objectives that can be solved or achieved by the multiple embodiments disclosed herein. [Means for solving the problem]

[0007] To solve the above problems, one form of communication device according to the present disclosure is a communication device that performs wireless communication using multiple channels, and comprises a generation unit that generates multiple bit sequences of different content by applying an encoding process based on a predetermined error correction coding scheme to a transmission data sequence, and a distribution unit that distributes the multiple bit sequences to the multiple channels. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram to explain PDCP duplication. [Figure 2] This figure shows an example of network coding application in the IAB domain. [Figure 3] This figure shows an example configuration of a communication system according to the embodiment of this disclosure. [Figure 4] This figure shows an example configuration of a management device according to an embodiment of this disclosure. [Figure 5] This figure shows an example of the configuration of a base station according to the present disclosure. [Figure 6] This figure shows an example of the configuration of a relay station according to the present disclosure. [Figure 7] It is a diagram showing a configuration example of a terminal device according to an embodiment of the present disclosure. [Figure 8] It is a diagram showing an outline of signal processing of a communication device on the transmission side. [Figure 9] It is a diagram showing an outline of signal processing of a communication device on the reception side. [Figure 10] It is a diagram for explaining the first encoding process. [Figure 11] It is a diagram showing an example of the first encoding process. [Figure 12] It is a diagram for explaining the second encoding process. [Figure 13] It is a sequence diagram showing an example of a procedure related to encoding. [Figure 14] It is a diagram showing an overall picture of the signal processing of this embodiment. [Figure 15] It is a diagram showing a specific example of the overall picture of the signal processing shown in FIG. 14. [Figure 16] It is a diagram showing a sequence example (basic form) of the communication processing of this embodiment. [Figure 17] It is a diagram showing a sequence example (modified example 1) of the communication processing of this embodiment. [Figure 18] It is a diagram showing a sequence example (modified example 2) of the communication processing of this embodiment. [Figure 19] It is a diagram showing a sequence example (modified example 3) of the communication processing of this embodiment. [Figure 20] It is a diagram showing an outline of the constructed simulation. [Figure 21] It is a diagram showing the specifications of this simulation. [Figure 22] It is a diagram showing simulation results. [Figure 23] It is a diagram showing simulation results.

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. In each of the following embodiments, the same parts are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] Also, in this specification and the drawings, there may be cases where a plurality of components having substantially the same functional configuration are distinguished by attaching different numbers after the same reference numeral. For example, a plurality of configurations having substantially the same functional configuration are distinguished as terminal devices 401, 402, and 403 as necessary. However, when it is not necessary to particularly distinguish each of a plurality of components having substantially the same functional configuration, only the same reference numeral is attached. For example, when it is not necessary to particularly distinguish the terminal devices 401, 402, and 403, they are simply referred to as the terminal device 40.

[0011] One or more of the embodiments (including examples and modifications) described below can be implemented independently. On the other hand, at least a part of the plurality of embodiments described below may be implemented in appropriate combination with at least a part of other embodiments. These plurality of embodiments may include different novel features from each other. Therefore, these plurality of embodiments can contribute to solving different purposes or problems from each other and can exhibit different effects from each other.

[0012] <<1. Overview>> Wireless access technologies (RAT: Radio Access Technology) such as LTE (Long Term Evolution) and NR (New Radio) are being studied in 3GPP (3rd Generation Partnership Project). LTE and NR are a type of cellular communication technology, and mobile communication of terminal devices is enabled by arranging a plurality of areas covered by a base station in a cell shape. At this time, a single base station may manage a plurality of cells.

[0013] In the following explanation, "LTE" includes LTE-A (LTE-Advanced), LTE-A Pro (LTE-Advanced Pro), and E-UTRA (Evolved Universal Terrestrial Radio Access). Similarly, "NR" includes NRAT (New Radio Access Technology) and FE-UTRA (Further E-UTRA). In the following explanation, cells supporting LTE are referred to as LTE cells, and cells supporting NR are referred to as NR cells.

[0014] NR is the next generation (fifth generation) of radio access technology (RAT) after LTE. NR is a radio access technology that can support a variety of use cases, including eMBB (Enhanced Mobile Broadband), mMTC (Massive Machine Type Communications), and URLLC (Ultra-Reliable and Low Latency Communications). NR is being developed with the aim of creating a technical framework that addresses the usage scenarios, requirements, and deployment scenarios in these use cases.

[0015] In recent years, there has been a demand for further improvements in communication performance (for example, greater capacity, higher speed, lower latency, higher reliability, lower power consumption, or lower processing load). Various technologies are used to achieve high communication performance, but simply using conventional technologies as they are does not necessarily guarantee high communication performance.

[0016] The following are examples of prior art: PDCP duplication (Packet Data Convergence Protocol Duplication) described in Non-Patent Document 1 (3GPP TS 38.323 version 16.2.0 Release 16), and the loss correction code application technology for multiple data units described in Non-Patent Document 2 (3GPP RP-193077).

[0017] (1) PDCP Duplication First, let's explain PDCP duplication. Figure 1 is a diagram illustrating PDCP duplication. PDCP duplication is a technology defined at the PDCP layer aimed at improving communication reliability. PDCP duplication is a type of packet duplication.

[0018] In PDCP duplication, the communication device duplicates a data unit to transmit the same data unit across multiple independent channels. The communication device then transmits the duplicated data unit using these multiple independent channels. Techniques that utilize multiple independent channels include Dual Connectivity and Carrier Aggregation, which are known technologies where a base station simultaneously uses multiple independent communication paths (channels) when communicating with a single terminal. These technologies primarily serve two purposes. First, to expand communication capacity and achieve high-capacity communication by using multiple independent communication paths. Second, to improve communication reliability by achieving spatial diversity through the use of multiple communication paths. PDCP duplication is used in communications that utilize multiple independent channels for the purpose of improving reliability in this way.

[0019] On the other hand, a drawback of PDCP duplication lies in its frequency utilization efficiency. For example, with PDCP duplication, if one of the identical data sent from independent channels is successfully received, all data sent from the remaining channels is discarded regardless of the success of the communication. Here, we assume that the coding rate below the PDCP layer is constant for each channel, and that the channel capacity is also constant. Under this assumption, we compare the frequency utilization efficiency with and without PDCP duplication. We find that using PDCP duplication uses N times more frequency resources than not using PDCP duplication, where N is the number of independent channels used for communication.

[0020] The receive processing performed by PDCP duplication has poor decoding gain and significantly lower frequency utilization efficiency compared to encoding techniques that use likelihood summation methods such as HARQ (Hybrid Automatic Repeat reQuest) or error correction using parity. In other words, while communication reliability improves when using PDCP duplication, frequency utilization efficiency decreases significantly. Therefore, it cannot be said that high communication performance is necessarily achieved even when using PDCP duplication.

[0021] (2) Technique for applying loss correction codes to multiple data units Next, we will describe a technique for applying loss correction codes to multiple data units. Non-patent document 2 describes applying network coding in IAB (Integrated Access and Backhaul). Network coding here refers to encoding packets with a predetermined loss correction code, for example. Figure 2 shows an example of network coding application in the IAB domain. In the example in Figure 2, the path for transmitting data to the IAB Donor is composed of multiple IAB nodes. In the example in Figure 2, IAB node 1, which receives the coded data, distributes and transmits the data to multiple paths. The distributed data is aggregated to a single IAB Donor. Then, data transmission between the base station (IAB Donor) and the terminal (UE) begins.

[0022] Non-Patent Document 2 describes communication between the IAB donor and the UE as using a single channel. Patent Document 2 assumes coding in the IAB domain. Furthermore, Non-Patent Document 2 does not describe any specific distribution method or lower-layer processing. Therefore, even if the technology described in Non-Patent Document 2 is used, it cannot be said that high communication performance will necessarily be achieved.

[0023] Therefore, in this embodiment, this problem is solved by the following means.

[0024] The communication device of this embodiment (for example, a base station and terminal device) performs wireless communication using multiple channels. The communication device generates multiple bit sequences with different content by applying a predetermined encoding process based on a predetermined error correction coding scheme to the transmitted data sequence. The communication device then distributes and transmits the multiple bit sequences to multiple channels. As a result, the communication device of this embodiment can achieve high frequency utilization efficiency while maintaining communication reliability.

[0025] Having outlined the basics of this embodiment, the communication system according to this embodiment will now be described in detail.

[0026] <<2. Communication System Configuration>> The configuration of communication system 1 will be explained in detail below, with reference to the diagrams.

[0027] <2-1. Overall Configuration of the Communication System> Figure 3 shows an example configuration of a communication system 1 according to an embodiment of the present disclosure. The communication system 1 comprises a management device 10, a base station 20, a relay station 30, and a terminal device 40. The communication system 1 provides a wireless network capable of mobile communication to a user through the coordinated operation of each wireless communication device constituting the communication system 1. The wireless network in this embodiment is composed of, for example, a wireless access network and a core network. In this embodiment, a wireless communication device is a device that has wireless communication functionality, and in the example of Figure 3, this refers to the base station 20, the relay station 30, and the terminal device 40.

[0028] The communication system 1 may include multiple management devices 10, base stations 20, relay stations 30, and terminal devices 40. In the example in Figure 3, the communication system 1 includes management devices 101, 102, etc. as management devices 10, and base stations 201, 202, etc. as base stations 20. The communication system 1 also includes relay stations 301, 302, etc. as relay stations 30, and terminal devices 401, 402, 403, etc. as terminal devices 40.

[0029] It should be noted that the devices in the diagram can be considered as devices in a logical sense. In other words, some of the devices in the diagram may be implemented as virtual machines (VMs), containers, Docker, etc., and these may be implemented on the same physical hardware.

[0030] Furthermore, communication system 1 may support radio access technologies (RAT: Radio Access Technology) such as LTE (Long Term Evolution) and NR (New Radio). LTE and NR are types of cellular communication technologies that enable mobile communication of terminal devices by arranging multiple base stations in a cell-like structure.

[0031] Furthermore, the wireless access method used by communication system 1 is not limited to LTE or NR, but may also be other wireless access methods such as W-CDMA (Wideband Code Division Multiple Access) or cdma2000 (Code Division Multiple Access 2000).

[0032] Furthermore, the base stations or relay stations constituting communication system 1 may be ground stations or non-ground stations. Non-ground stations may be satellite stations or aircraft stations. If the non-ground station is a satellite station, communication system 1 may be a bent-pipe (transparent) type mobile satellite communication system.

[0033] In this embodiment, a ground station (also called a ground base station) refers to a base station (including relay stations) installed on the ground. Here, "ground" is a broad term that includes not only land but also underground, on water, and underwater. In the following explanation, the term "ground station" may be replaced with "gateway."

[0034] Note that LTE base stations are sometimes referred to as eNodeB (Evolved Node B) or eNB. Similarly, NR base stations are sometimes referred to as gNodeB or gNB. In both LTE and NR, terminal equipment (also called mobile stations or terminals) is sometimes referred to as UE (User Equipment). Note that terminal equipment is a type of communication device and is also called a mobile station or terminal.

[0035] In this embodiment, the concept of a communication device includes not only portable mobile devices (terminal devices) such as mobile terminals, but also devices installed on structures or mobile objects. Structures or mobile objects themselves may be considered communication devices. Furthermore, the concept of a communication device includes not only terminal devices, but also base stations and relay stations. A communication device is a type of processing device and information processing device. A communication device can also be referred to as a transmitting device or a receiving device.

[0036] The configuration of each device constituting communication system 1 will be described in detail below. Note that the configurations of each device shown below are merely examples. The configuration of each device may differ from those shown below.

[0037] <2-2. Configuration of the control device> Next, the configuration of the control device 10 will be described.

[0038] The management device 10 is a device that manages the wireless network. For example, the management device 10 is a device that manages the communication of the base station 20. The management device 10 may also be a device that functions as an MME (Mobility Management Entity). The management device 10 may also be a device that functions as an AMF (Access and Mobility Management Function) and / or an SMF (Session Management Function). Of course, the functions of the management device 10 are not limited to MME, AMF, and SMF. The management device 10 may also be a device that functions as an NSSF (Network Slice Selection Function), AUSF (Authentication Server Function), PCF (Policy Control Function), or UDM (Unified Data Management). Furthermore, the management device 10 may also be a device that functions as an HSS (Home Subscriber Server).

[0039] Furthermore, the management device 10 may also have gateway functionality. For example, the management device 10 may function as an S-GW (Serving Gateway) or a P-GW (Packet Data Network Gateway). In addition, the management device 10 may also function as a UPF (User Plane Function).

[0040] The core network consists of multiple network functions, each of which may be aggregated in a single physical device or distributed across multiple physical devices. In other words, the management device 10 can be distributed across multiple devices. Furthermore, this distributed distribution may be controlled to be performed dynamically. The base station 20 and the management device 10 form a single network and provide wireless communication services to the terminal device 40. The management device 10 is connected to the internet, and the terminal device 40 can use various services provided via the internet through the base station 20.

[0041] Note that the management device 10 does not necessarily have to be a device that constitutes the core network. For example, suppose the core network is a W-CDMA (Wideband Code Division Multiple Access) or cdma2000 (Code Division Multiple Access 2000) core network. In this case, the management device 10 may be a device that functions as an RNC (Radio Network Controller).

[0042] Figure 4 shows an example configuration of a management device 10 according to an embodiment of the present disclosure. The management device 10 comprises a communication unit 11, a storage unit 12, and a control unit 13. Note that the configuration shown in Figure 4 is a functional configuration, and the hardware configuration may differ. Furthermore, the functions of the management device 10 may be implemented by statically or dynamically distributing them across multiple physically separated configurations. For example, the management device 10 may be composed of multiple server devices.

[0043] The communication unit 11 is a communication interface for communicating with other devices. The communication unit 11 may be a network interface or an equipment connection interface. For example, the communication unit 11 may be a LAN (Local Area Network) interface such as a NIC (Network Interface Card), or a USB interface consisting of a USB (Universal Serial Bus) host controller, USB port, etc. Furthermore, the communication unit 11 may be a wired interface or a wireless interface. The communication unit 11 functions as a communication means for the management device 10. The communication unit 11 communicates with the base station 20, etc., according to the control of the control unit 13.

[0044] The memory unit 12 is a data read / write storage device such as DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), flash memory, or hard disk. The memory unit 12 functions as a storage means for the management device 10. The memory unit 12 stores, for example, the connection status of the terminal device 40. For example, the memory unit 12 stores the RRC (Radio Resource Control) status, ECM (EPS Connection Management) status, or 5G System CM (Connection Management) status of the terminal device 40. The memory unit 12 may also function as a home memory that stores the location information of the terminal device 40.

[0045] The control unit 13 is a controller that controls each part of the management device 10. The control unit 13 is implemented by a processor such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), or GPU (Graphics Processing Unit). For example, the control unit 13 is implemented by the processor executing various programs stored in the internal storage device of the management device 10 using RAM (Random Access Memory) or the like as a working area. The control unit 13 may also be implemented by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array). CPUs, MPUs, GPUs, ASICs, and FPGAs can all be considered controllers.

[0046] <2-3. Base Station Configuration> Next, we will explain the configuration of base station 20.

[0047] The base station 20 is a wireless communication device that communicates wirelessly with the terminal device 40. The base station 20 may be configured to communicate wirelessly with the terminal device 40 via a relay station 30, or it may be configured to communicate wirelessly with the terminal device 40 directly.

[0048] Base station 20 is a type of communication device. More specifically, base station 20 is a device equivalent to a wireless base station (Base Station, Node B, eNB, gNB, etc.) or a wireless access point. Base station 20 may also be a wireless relay station. Base station 20 may also be an optical extension device called an RRH (Remote Radio Head) or RU (Radio Unit). Base station 20 may also be a receiving station such as an FPU (Field Pickup Unit). Base station 20 may also be an IAB (Integrated Access and Backhaul) donor node or IAB relay node that provides wireless access lines and wireless backhaul lines using time division multiplexing, frequency division multiplexing, or spatial division multiplexing.

[0049] The wireless access technology used by base station 20 may be cellular communication technology or wireless LAN technology. Of course, the wireless access technology used by base station 20 is not limited to these and may be other wireless access technologies. For example, the wireless access technology used by base station 20 may be LPWA (Low Power Wide Area) communication technology. Of course, the wireless communication used by base station 20 may be wireless communication using millimeter waves. Furthermore, the wireless communication used by base station 20 may be wireless communication using radio waves, or wireless communication using infrared or visible light (optical wireless).

[0050] Base station 20 may be capable of NOMA (Non-Orthogonal Multiple Access) communication with terminal device 40. Here, NOMA communication refers to communication (transmission, reception, or both) using non-orthogonal resources. Base station 20 may also be capable of NOMA communication with other base stations 20.

[0051] Furthermore, the base stations 20 may be able to communicate with each other via base station-core network interfaces (e.g., NG Interface, S1 Interface, etc.). These interfaces may be either wired or wireless. In addition, the base stations may be able to communicate with each other via inter-base station interfaces (e.g., Xn Interface, X2 Interface, S1 Interface, F1 Interface, etc.). These interfaces may be either wired or wireless.

[0052] Furthermore, the concept of a base station includes not only donor base stations but also relay base stations (also called relay stations). For example, a relay base station may be any one of the following: an RF Repeater, a Smart Repeater, or an Intelligent Surface. Also, the concept of a base station includes not only structures equipped with base station functions but also equipment installed on those structures.

[0053] Structures include buildings such as skyscrapers, houses, transmission towers, train stations, airports, ports, office buildings, school buildings, hospitals, factories, commercial facilities, and stadiums. The concept of structures also includes not only buildings but also non-building structures such as tunnels, bridges, dams, walls, and steel columns, as well as equipment such as cranes, gates, and wind turbines. Furthermore, the concept of structures includes not only structures on land (in the narrow sense of the ground) or underground, but also structures on water such as piers and megafloats, and underwater structures such as oceanographic observation equipment. A base station can be rephrased as an information processing device.

[0054] Base station 20 may be a donor station or a relay station. Furthermore, base station 20 may be a fixed station or a mobile station. A mobile station is a wireless communication device (e.g., a base station) configured to be mobile. In this case, base station 20 may be a device installed on a mobile object or the mobile object itself. For example, a relay station with mobility can be considered a base station 20 as a mobile station. Additionally, devices that are inherently mobile and equipped with base station functions (or at least some of the functions of a base station), such as vehicles, UAVs (Unmanned Aerial Vehicles) represented by drones, and smartphones, also qualify as base station 20 as a mobile station.

[0055] Here, the moving object may be a mobile device such as a smartphone or mobile phone. Furthermore, the moving object may be a moving object that moves on land (on the ground in the narrow sense) (for example, a car, bicycle, bus, truck, motorcycle, train, maglev train, etc.) or a moving object that moves underground (for example, inside a tunnel) (for example, a subway).

[0056] Furthermore, the mobile object may be a mobile object that moves on the water (for example, a passenger ship, cargo ship, hovercraft, or other vessel) or a mobile object that moves underwater (for example, a submersible, submarine, or unmanned underwater vehicle).

[0057] Furthermore, the moving object may be a moving object that moves within the atmosphere (for example, an aircraft such as an airplane, airship, or drone).

[0058] Furthermore, base station 20 may be a ground base station (ground station) installed on the ground. For example, base station 20 may be a base station located on a structure on the ground, or a base station installed on a mobile device moving on the ground. More specifically, base station 20 may be an antenna installed on a structure such as a building and a signal processing device connected to that antenna. Of course, base station 20 may be the structure or mobile device itself. "Ground" refers to ground in a broad sense, including not only land (ground in the narrow sense) but also underground, on water, and underwater. Note that base station 20 is not limited to a ground base station. For example, if communication system 1 is a satellite communication system, base station 20 may be an aircraft station. From the perspective of a satellite station, an aircraft station located on Earth is a ground station.

[0059] Furthermore, base station 20 is not limited to a ground station. Base station 20 may also be a non-ground base station (non-ground station) capable of floating in the air or space. For example, base station 20 may be an aircraft station or a satellite station.

[0060] A satellite station is a satellite station capable of floating outside the atmosphere. A satellite station may be a device mounted on a space-based mobile vehicle such as an artificial satellite, or it may be the space-based mobile vehicle itself. A space-based mobile vehicle is a mobile vehicle that moves outside the atmosphere. Examples of space-based mobile vehicles include artificial satellites, spacecraft, space stations, probes, and other artificial celestial bodies.

[0061] The satellite serving as the satellite station may be a low Earth orbit (LEO), medium Earth orbit (MEO), geostationary Earth orbit (GEO), or highly elliptical orbit (HEO) satellite. Of course, the satellite station may also be equipment mounted on a low Earth orbit satellite, medium Earth orbit satellite, geostationary satellite, or highly elliptical orbit satellite.

[0062] An aircraft station is a radio communication device capable of floating within the atmosphere, such as an aircraft. An aircraft station may be a device mounted on an aircraft, or it may be the aircraft itself. The concept of an aircraft includes not only heavy aircraft such as airplanes and gliders, but also light aircraft such as balloons and airships. Furthermore, the concept of an aircraft includes not only heavy and light aircraft, but also rotary-wing aircraft such as helicopters and autogyros. An aircraft station (or the aircraft on which an aircraft station is mounted) may also be an unmanned aerial vehicle such as a drone.

[0063] The concept of unmanned aerial vehicles (UAS) also includes unmanned aircraft systems (UAS) and tethered UAS. Furthermore, the concept of unmanned aerial vehicles includes lighter than air UAS (LTA) and heavier than air UAS (HTA). In addition, the concept of unmanned aerial vehicles also includes high-altitude UAS platforms (HAPs).

[0064] The coverage size of base station 20 can range from large, like a macrocell, to small, like a picocell. Of course, the coverage size of base station 20 can also be extremely small, like a femtocell. Furthermore, base station 20 may have beamforming capabilities. In this case, base station 20 may form cells or service areas for each beam.

[0065] Figure 5 shows an example configuration of a base station 20 according to the present disclosure. The base station 20 comprises a wireless communication unit 21, a storage unit 22, and a control unit 23. Note that the configuration shown in Figure 5 is a functional configuration, and the hardware configuration may differ. Furthermore, the functions of the base station 20 may be distributed and implemented across multiple physically separated configurations.

[0066] The wireless communication unit 21 is a signal processing unit for wireless communication with other wireless communication devices (e.g., terminal device 40). The wireless communication unit 21 operates according to the control of the control unit 23. The wireless communication unit 21 supports one or more wireless access methods. For example, the wireless communication unit 21 supports both NR and LTE. In addition to NR and LTE, the wireless communication unit 21 may also support W-CDMA and cdma2000. Furthermore, the wireless communication unit 21 may support automatic retransmission technologies such as HARQ (Hybrid Automatic Repeat reQuest).

[0067] The wireless communication unit 21 comprises a transmission processing unit 211, a reception processing unit 212, and an antenna 213. The wireless communication unit 21 may comprise multiple transmission processing units 211, reception processing units 212, and antennas 213. When the wireless communication unit 21 supports multiple wireless access methods, each part of the wireless communication unit 21 may be configured individually for each wireless access method. For example, the transmission processing unit 211 and the reception processing unit 212 may be configured individually for LTE and NR. The antenna 213 may also consist of multiple antenna elements (e.g., multiple patch antennas). In this case, the wireless communication unit 21 may be configured to be beamforming capable. The wireless communication unit 21 may also be configured to be polarization beamforming capable of using vertical polarization (V polarization) and horizontal polarization (H polarization).

[0068] The transmission processing unit 211 performs the transmission processing of downlink control information and downlink data. For example, the transmission processing unit 211 encodes the downlink control information and downlink data input from the control unit 23 using an encoding method such as block coding, convolutional coding, or turbo coding. Here, encoding may be done using polar coding or LDPC coding (Low Density Parity Check Code). The transmission processing unit 211 then modulates the encoded bits using a predetermined modulation method such as BPSK, QPSK, 16QAM, 64QAM, or 256QAM. In this case, the signal points on the constellation do not necessarily have to be equidistant. The constellation may be a non-uniform constellation (NUC). The transmission processing unit 211 then multiplexes the modulation symbols and downlink reference signals for each channel and places them in predetermined resource elements. The transmission processing unit 211 then performs various signal processing on the multiplexed signals. For example, the transmission processing unit 211 performs processing such as conversion to the frequency domain using the Fast Fourier Transform, addition of a guard interval (cyclic prefix), generation of a baseband digital signal, conversion to an analog signal, quadrature modulation, upconversion, removal of extraneous frequency components, and power amplification. The signal generated by the transmission processing unit 211 is transmitted from the antenna 213.

[0069] The receiving processing unit 212 processes the uplink signal received via the antenna 213. For example, the receiving processing unit 212 performs down-conversion, removal of unwanted frequency components, amplification level control, quadrature demodulation, conversion to a digital signal, removal of guard intervals (cyclic prefixes), and extraction of frequency domain signals using the Fast Fourier Transform on the uplink signal. Then, the receiving processing unit 212 separates the uplink channels and uplink reference signals, such as PUSCH (Physical Uplink Shared Channel) and PUCCH (Physical Uplink Control Channel), from the processed signal. The receiving processing unit 212 also demodulates the received signal using modulation schemes such as BPSK (Binary Phase Shift Keying) and QPSK (Quadrature Phase Shift Keying) for the modulation symbols of the uplink channels. The modulation scheme used for demodulation may be 16QAM (Quadrature Amplitude Modulation), 64QAM, or 256QAM. In this case, the signal points on the constellation do not necessarily need to be equidistant. The constellation may be a non-uniform constellation (NUC). The receiving processing unit 212 then performs decoding on the encoded bits of the demodulated uplink channel. The decoded uplink data and uplink control information are output to the control unit 23.

[0070] Antenna 213 is an antenna device (antenna unit) that converts electric current and radio waves to each other. Antenna 213 may consist of one antenna element (e.g., one patch antenna) or multiple antenna elements (e.g., multiple patch antennas). If antenna 213 consists of multiple antenna elements, the wireless communication unit 21 may be configured to beamform. For example, the wireless communication unit 21 may be configured to generate a directional beam by controlling the directivity of the wireless signal using multiple antenna elements. Antenna 213 may also be a dual-polarization antenna. If antenna 213 is a dual-polarization antenna, the wireless communication unit 21 may use vertical polarization (V polarization) and horizontal polarization (H polarization) when transmitting the wireless signal. The wireless communication unit 21 may then control the directivity of the transmitted wireless signal using vertical polarization and horizontal polarization. Furthermore, the wireless communication unit 21 may transmit and receive spatially multiplexed signals through multiple layers composed of multiple antenna elements.

[0071] The memory unit 22 is a data read / write storage device such as DRAM, SRAM, flash memory, or hard disk. The memory unit 22 functions as a storage means for the base station 20.

[0072] The control unit 23 is a controller that controls various parts of the base station 20. The control unit 23 is implemented by a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). For example, the control unit 23 is implemented by the processor executing various programs stored in the memory device inside the base station 20, using RAM (Random Access Memory) or the like as a working area. The control unit 23 may also be implemented by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). CPUs, MPUs, ASICs, and FPGAs can all be considered controllers. In addition, the control unit 23 may be implemented by a GPU (Graphics Processing Unit) in addition to, or instead of, a CPU.

[0073] The control unit 23 comprises a receiving unit 231, a transmitting unit 232, an acquisition unit 233, a generation unit 234, a distribution unit 235, a start determination unit 236, a decoding unit 237, and a decoding determination unit 238. Each block constituting the control unit 23 (receiving unit 231 to decoding determination unit 238) is a functional block that indicates the function of the control unit 23. These functional blocks may be software blocks or hardware blocks. For example, each of the above-mentioned functional blocks may be a single software module implemented in software (including microprograms), or a single circuit block on a semiconductor chip (die). Of course, each functional block may also be a single processor or a single integrated circuit. The control unit 23 may be composed of functional units different from the above-mentioned functional blocks. The method of configuring the functional blocks is arbitrary. Note that the operation of the control unit 23 may be the same as the operation of each block of the control unit of the terminal device 40.

[0074] In some embodiments, the concept of a base station may consist of a collection of multiple physical or logical devices. For example, in this embodiment, a base station may be distinguished into multiple devices such as a BBU (Baseband Unit) and an RU (Radio Unit). The base station may be interpreted as a collection of these multiple devices. Furthermore, a base station may consist of either a BBU or an RU, or both. The BBU and RU may be connected by a predetermined interface (e.g., eCPRI (enhanced Common Public Radio Interface)). Note that RU may be rephrased as RRU (Remote Radio Unit) or RD (Radio DoT). Also, the RU may correspond to a gNB-DU (gNB Distributed Unit) described later. Furthermore, the BBU may correspond to a gNB-CU (gNB Central Unit) described later. Alternatively, the RU may be a radio device connected to a gNB-DU described later. The gNB-CU, gNB-DU, and RU connected to the gNB-DU may be configured to comply with O-RAN (Open Radio Access Network). Furthermore, the RU may be a device formed integrally with an antenna. The antennas of the base station (for example, antennas integrated with the RU) may employ an Advanced Antenna System and support MIMO (e.g., FD-MIMO) and beamforming. Furthermore, the antennas of the base station may have, for example, 64 transmitting antenna ports and 64 receiving antenna ports.

[0075] Furthermore, the antenna mounted on the RU may be an antenna panel composed of one or more antenna elements, and the RU may be equipped with one or more antenna panels. For example, the RU may be equipped with two types of antenna panels, a horizontally polarized antenna panel and a vertically polarized antenna panel, or two types of antenna panels, a right-hand circularly polarized antenna panel and a left-hand circularly polarized antenna panel. In addition, the RU may form and control independent beams for each antenna panel.

[0076] Multiple base stations may be interconnected. One or more base stations may be included in a Radio Access Network (RAN). In this case, the base station may simply be referred to as RAN, RAN node, AN (Access Network), or AN node. In LTE, the RAN is sometimes called EUTRAN (Enhanced Universal Terrestrial RAN). In NR, the RAN is sometimes called NGRAN. In W-CDMA (UMTS), the RAN is sometimes called UTRAN.

[0077] Furthermore, LTE base stations are sometimes referred to as eNodeB (Evolved Node B) or eNB. In this case, EUTRAN includes one or more eNodeBs (eNBs). Similarly, NR base stations are sometimes referred to as gNodeB or gNB. In this case, NGRAN includes one or more gNBs. EUTRAN may also include gNBs (en-gNBs) connected to the core network (EPC) in the LTE communication system (EPS). Likewise, NGRAN may include ng-eNBs connected to the core network 5GC in the 5G communication system (5GS).

[0078] Furthermore, if the base station is an eNB or gNB, it may be referred to as 3GPP Access. If the base station is an Access Point, it may be referred to as Non-3GPP Access. Additionally, the base station may be an optical extension device called an RRH (Remote Radio Head) or RU (Radio Unit). If the base station is a gNB, it may be a combination of the aforementioned gNB-CU and gNB-DU, or it may be either a gNB-CU or a gNB-DU.

[0079] Here, the gNB-CU hosts several upper layers of the Access Stratum (e.g., RRC (Radio Resource Control), SDAP (Service Data Adaptation Protocol), and PDCP (Packet Data Convergence Protocol)) for communication with the UE. On the other hand, the gNB-DU hosts several lower layers of the Access Stratum (e.g., RLC (Radio Link Control), MAC (Medium Access Control), and PHY (Physical layer)). That is, among the messages / information described later, RRC signaling (quasi-static notifications) may be generated by the gNB-CU, while MAC CE and DCI (dynamic notifications) may be generated by the gNB-DU. Alternatively, among the RRC configuration (quasi-static notifications), some configurations, such as IE:cellGroupConfig, may be generated by the gNB-DU, and the remaining configurations may be generated by the gNB-CU. These configurations may be sent and received via the F1 interface described later.

[0080] Furthermore, a base station may be configured to communicate with other base stations. For example, if multiple base stations are eNBs or a combination of eNB and en-gNB, they may be connected via an X2 interface. Also, if multiple base stations are gNBs or a combination of gn-eNB and gNB, they may be connected via an Xn interface. Also, if multiple base stations are a combination of gNB-CU and gNB-DU, they may be connected via the F1 interface described above. Messages / information described later (e.g., RRC signaling, MAC CE (MAC Control Element), or DCI) may be transmitted between multiple base stations, for example, via an X2 interface, Xn interface, or F1 interface.

[0081] Cells provided by a base station are sometimes called serving cells. The concept of a serving cell includes PCell (Primary Cell) and SCell (Secondary Cell). When dual connectivity is configured on the UE (e.g., terminal device 40), the PCell and zero or one or more SCells provided by the MN (Master Node) are sometimes called a Master Cell Group. Examples of dual connectivity include EUTRA-EUTRA Dual Connectivity, EUTRA-NR Dual Connectivity (ENDC), EUTRA-NR Dual Connectivity with 5GC, NR-EUTRA Dual Connectivity (NEDC), and NR-NR Dual Connectivity.

[0082] A serving cell may include a PSCell (Primary Secondary Cell, or Primary SCG Cell). When dual connectivity is configured for the UE, the PSCell provided by the SN (Secondary Node), and zero or more SCells, are sometimes referred to as an SCG (Secondary Cell Group). Unless otherwise specified (e.g., PUCCH on SCell), the Physical Uplink Control Channel (PUCCH) is transmitted by both PCells and PSCells, but not by SCells. Similarly, Radio Link Failure is detected by both PCells and PSCells, but not by SCells (and does not need to be detected). Because PCells and PSCells have special roles within a serving cell, they are also called SpCells (Special Cells).

[0083] A single cell may be associated with one downlink component carrier and one uplink component carrier. Furthermore, the system bandwidth corresponding to a single cell may be divided into multiple Bandwidth Parts (BWPs). In this case, one or more BWPs may be configured as UEs, with one BWP being used by the UE as the Active BWP. Additionally, the radio resources available to the terminal device 40 (e.g., frequency band, numerology (subcarrier spacing), slot configuration) may differ for each cell, component carrier, or BWP.

[0084] <2-4. Relay Station Configuration> Next, I will explain the configuration of the relay station 30.

[0085] The relay station 30 is a device that acts as a relay station for a base station. The relay station 30 is a type of base station. The relay station 30 is also a type of information processing device. A relay station can be referred to as a relay base station. The relay station 30 may also be a device called a repeater (e.g., RF Repeater, Smart Repeater, Intelligent Surface).

[0086] The relay station 30 is capable of wireless communication, such as NOMA communication, with the terminal device 40. The relay station 30 relays communication between the base station 20 and the terminal device 40. The relay station 30 may also be configured to enable wireless communication with other relay stations 30 and base stations 20. The relay station 30 may be a ground station or a non-ground station. The relay station 30, together with the base station 20, constitutes a wireless access network (RAN).

[0087] Furthermore, the relay station in this embodiment may be a fixed device, a movable device, or a floating device. Also, the coverage size of the relay station in this embodiment is not limited to a specific size. For example, the cells covered by the relay station may be macrocells, microcells, or small cells.

[0088] Furthermore, the relay station of this embodiment is not limited to the device it is mounted on, as long as the relay function is fulfilled. For example, the relay station may be mounted on a terminal device such as a smartphone, on an automobile, train or rickshaw, on a balloon or airplane or drone, on a traffic light, sign or streetlamp, or on a home appliance such as a television, game console, air conditioner, refrigerator or lighting fixture.

[0089] Furthermore, the configuration of the relay station 30 may be the same as that of the base station 20 described above. For example, the relay station 30 may be a device installed on a mobile device, or it may be the mobile device itself, similar to the base station 20 described above. The mobile device may be a mobile terminal such as a smartphone or mobile phone, as described above. The mobile device may also be a mobile device that moves on land (ground in the narrow sense) or a mobile device that moves underground. Of course, the mobile device may also be a mobile device that moves on water or a mobile device that moves underwater. Furthermore, the mobile device may also be a mobile device that moves within the atmosphere or a mobile device that moves outside the atmosphere. In addition, the relay station 30 may be a ground station device or a non-ground station device. In this case, the relay station 30 may also be an aircraft station or a satellite station.

[0090] Furthermore, the coverage size of the relay station 30 may range from large macrocells to small picocells, similar to the base station 20. Of course, the coverage size of the relay station 30 may also be extremely small, such as femtocells. The relay station 30 may also have beamforming capabilities. In this case, cells or service areas may be formed for each beam of the relay station 30.

[0091] Figure 6 shows an example configuration of a relay station 30 according to the present disclosure. The relay station 30 comprises a wireless communication unit 31, a storage unit 32, and a control unit 33. Note that the configuration shown in Figure 6 is a functional configuration, and the hardware configuration may differ. Furthermore, the functions of the relay station 30 may be distributed and implemented across multiple physically separated configurations.

[0092] The wireless communication unit 31 is a wireless communication interface that communicates wirelessly with other wireless communication devices (e.g., base station 20, terminal device 40, other relay station 30). The wireless communication unit 31 supports one or more wireless access methods. For example, the wireless communication unit 31 supports both NR and LTE. In addition to NR and LTE, the wireless communication unit 31 may also support W-CDMA and cdma2000. The wireless communication unit 31 comprises a transmission processing unit 311, a reception processing unit 312, and an antenna 313. The wireless communication unit 31 may have multiple transmission processing units 311, reception processing units 312, and antennas 313. When the wireless communication unit 31 supports multiple wireless access methods, each part of the wireless communication unit 31 may be configured individually for each wireless access method. For example, the transmission processing unit 311 and the reception processing unit 312 may be configured individually for LTE and NR. The configuration of the transmission processing unit 311, reception processing unit 312, and antenna 313 is the same as the configuration of the transmission processing unit 211, reception processing unit 212, and antenna 213 described above. The wireless communication unit 31 may also be configured to be beamforming-capable, similar to the wireless communication unit 21.

[0093] The memory unit 32 is a data read / write storage device such as DRAM, SRAM, flash memory, or hard disk. The memory unit 32 functions as a storage means for the relay station 30.

[0094] The control unit 33 is a controller that controls each part of the relay station 30. The control unit 33 is implemented by a processor such as a CPU, MPU, or GPU. For example, the control unit 33 is implemented by the processor executing various programs stored in the internal memory of the relay station 30 using RAM or the like as a working area. The control unit 33 may also be implemented by an integrated circuit such as an ASIC or FPGA. CPUs, MPUs, GPUs, ASICs, and FPGAs can all be considered controllers. The operation of the control unit 33 may be the same as the operation of each block (receiving unit 231 to decoding determination unit 238) of the control unit 23 of the base station 20.

[0095] The relay station 30 may also be an IAB relay node. The relay station 30 operates as an IAB-MT (Mobile Termination) for the IAB donor node that provides backhaul, and as an IAB-DU (Distributed Unit) for the terminal device 40 that provides access. The IAB donor node may be, for example, a base station 20, which operates as an IAB-CU (Central Unit).

[0096] <2-5. Terminal Device Configuration> Next, the configuration of the terminal device 40 will be described.

[0097] Terminal device 40 is a wireless communication device that communicates wirelessly with other communication devices such as base station 20 and relay station 30. Terminal device 40 may be, for example, a mobile phone, a smart device (smartphone or tablet), a PDA (Personal Digital Assistant), or a personal computer. Alternatively, terminal device 40 may be a professional camera equipped with communication functions, or a motorcycle or mobile relay vehicle equipped with communication equipment such as an FPU (Field Pickup Unit). Furthermore, terminal device 40 may be an M2M (Machine to Machine) device or an IoT (Internet of Things) device.

[0098] The terminal device 40 may be capable of NOMA communication with the base station 20. Furthermore, the terminal device 40 may use automatic retransmission technology such as HARQ when communicating with the base station 20. The terminal device 40 may be capable of sidelink communication with other terminal devices 40. The terminal device 40 may also use automatic retransmission technology such as HARQ when performing sidelink communication. Furthermore, the terminal device 40 may be capable of NOMA communication even when communicating with other terminal devices 40 (sidelink). Furthermore, the terminal device 40 may be capable of LPWA communication with other communication devices (for example, the base station 20 and other terminal devices 40). Furthermore, the wireless communication used by the terminal device 40 may be millimeter-wave wireless communication. Furthermore, the wireless communication used by the terminal device 40 (including sidelink communication) may be radio wave wireless communication, or infrared or visible light wireless communication (optical wireless).

[0099] Furthermore, the terminal device 40 may be a mobile device. The mobile device is a portable wireless communication device. In this case, the terminal device 40 may be a wireless communication device installed on the mobile device, or it may be the mobile device itself. For example, the terminal device 40 may be a vehicle that moves on roads, such as an automobile, bus, truck, or motorcycle; a vehicle that moves on rails installed on tracks, such as a train; or a wireless communication device mounted on such a vehicle. The mobile device may be a mobile terminal, or a mobile device that moves on land (ground in the narrow sense), underground, on water, or underwater. The mobile device may also be a mobile device that moves within the atmosphere, such as a drone or helicopter, or a mobile device that moves outside the atmosphere, such as an artificial satellite.

[0100] The terminal device 40 may simultaneously connect to and communicate with multiple base stations or multiple cells. For example, if one base station supports a communication area via multiple cells (e.g., pCell, sCell), it is possible to combine these multiple cells using carrier aggregation (CA), dual connectivity (DC), or multi-connectivity (MC) technologies to enable communication between the base station 20 and the terminal device 40. Alternatively, the terminal device 40 can communicate with multiple base stations 20 via cells of different base stations 20 using coordinated multi-point transmission and reception (CoMP) technology.

[0101] Figure 7 shows an example configuration of a terminal device 40 according to the present disclosure. The terminal device 40 comprises a wireless communication unit 41, a storage unit 42, and a control unit 43. Note that the configuration shown in Figure 7 is a functional configuration, and the hardware configuration may differ. Furthermore, the functions of the terminal device 40 may be implemented in a distributed manner across multiple physically separated configurations.

[0102] The wireless communication unit 41 is a signal processing unit for wireless communication with other wireless communication devices (e.g., base station 20, relay station 30, and other terminal devices 40). The wireless communication unit 41 operates according to the control of the control unit 43. The wireless communication unit 41 comprises a transmission processing unit 411, a reception processing unit 412, and an antenna 413. The configuration of the wireless communication unit 41, transmission processing unit 411, reception processing unit 412, and antenna 413 may be the same as that of the wireless communication unit 21, transmission processing unit 211, reception processing unit 212, and antenna 213 of the base station 20. Furthermore, the wireless communication unit 41 may be configured to be beamforming, similar to the wireless communication unit 21. In addition, the wireless communication unit 41 may be configured to transmit and receive spatially multiplexed signals, similar to the wireless communication unit 21.

[0103] The memory unit 42 is a data read / write storage device such as DRAM, SRAM, flash memory, or hard disk. The memory unit 42 functions as a storage means for the terminal device 40.

[0104] The control unit 43 is a controller that controls various parts of the terminal device 40. The control unit 43 is implemented by a processor such as a CPU or MPU. For example, the control unit 43 is implemented by the processor executing various programs stored in the memory device inside the terminal device 40 using RAM or the like as a working area. The control unit 43 may also be implemented by an integrated circuit such as an ASIC or FPGA. CPU, MPU, ASIC, and FPGA can all be considered as controllers. In addition, the control unit 43 may be implemented by a GPU in addition to, or instead of, the CPU.

[0105] The control unit 43 comprises a receiving unit 431, a transmitting unit 432, an acquisition unit 433, a generation unit 434, a distribution unit 435, a start determination unit 436, a decoding unit 437, and a decoding determination unit 438. Each block constituting the control unit 43 (receiving unit 431 to decoding determination unit 438) is a functional block that indicates the function of the control unit 43. These functional blocks may be software blocks or hardware blocks. For example, each of the above-mentioned functional blocks may be a single software module implemented in software (including microprograms), or a single circuit block on a semiconductor chip (die). Of course, each functional block may also be a single processor or a single integrated circuit. The control unit 43 may be composed of functional units different from the above-mentioned functional blocks. The method of configuring the functional blocks is arbitrary. The operation of the control unit 43 may be the same as the operation of each block of the control unit 23 of the base station 20.

[0106] <<3. Operation of the Communication System>> Having described the configuration of the communication system 1 of this embodiment, the signal processing of this embodiment will now be described.

[0107] <3-1. Overview of the Communication System's Operation> First, I will explain the overview of the operation of communication system 1.

[0108] <3-1-1. Overview of Signal Processing> Figures 8 and 9 show an overview of the signal processing in this embodiment. Figure 8 shows an overview of the signal processing of the transmitting communication device, and Figure 9 shows an overview of the signal processing of the receiving communication device. Any of the base station 20, relay station 30, and terminal device 40 can be the transmitting or receiving communication device. In this embodiment, the communication device applies a plurality of error correction (FEC: Forward Error Correction) processes to the information sequence to be transmitted and received.

[0109] In the example shown in Figure 8, error correction processing is performed in both the first and second encoding. First, a predetermined signal processing layer within the communication device acquires an information sequence from a higher layer (e.g., the SDAP layer or RRC layer), performs predetermined signal processing (transmitter-side processing 1 shown in Figure 8), and transmits that information sequence (hereinafter also referred to as the transmission data sequence) to the first encoding layer (e.g., the PDCP layer). The first encoding layer performs a first encoding process on the received transmission data sequence. The first encoding process includes a first error correction encoding process. After the encoded transmission data sequence undergoes predetermined signal processing (transmitter-side processing 2 shown in Figure 8), it is transmitted to the second encoding layer (e.g., the physical layer). The second encoding layer performs a second encoding process on the transmission data sequence. The second encoding process includes a second error correction encoding process. After the encoded transmission data sequence undergoes predetermined signal processing (transmitter-side processing 3 shown in Figure 8), it is transmitted to the receiving communication device.

[0110] Furthermore, in the example shown in Figure 9, error correction processing is performed in both the first and second decoding processes. First, a predetermined signal processing layer within the communication device acquires an information sequence (hereinafter also referred to as the received data sequence) from the transmitting communication device, performs predetermined signal processing (receiving-side processing 1 shown in Figure 9), and transmits the received data sequence to the second decoding layer (e.g., the physical layer). The second decoding layer performs a second decoding process on the received data sequence that corresponds to the second encoding process. The decoded received data sequence undergoes predetermined signal processing (receiving-side processing 2 shown in Figure 9) and is then transmitted to the first decoding layer (e.g., the PDCP layer). The first decoding layer performs a first decoding process on the received data sequence that corresponds to the first encoding process. The information sequence generated by the first decoding process undergoes predetermined signal processing (receiving-side processing 3 shown in Figure 8) and is then transmitted to the upper layer.

[0111] The communication device of this embodiment generates multiple bit sequences with different content by applying a first encoding process based on a first error correction coding scheme to the transmitted data sequence, and distributes and transmits these multiple bit sequences to multiple channels. As a result, the communication device achieves high frequency utilization efficiency while maintaining communication reliability.

[0112] <3-1-2. Encoding Process> The first encoding process and the second encoding process will be described below. Note that the first decoding process and the second decoding process correspond to the first encoding process or the second encoding process, respectively, so their explanations will be omitted.

[0113] (A) First encoding process Figure 10 is a diagram illustrating the first encoding process. In the first encoding process, multiple bit sequences are generated from a single bit sequence. Here, the single bit sequence that becomes the input to the first encoding process corresponds to the transmission data sequence described above. In the first encoding process, the communication device may divide the output multiple bit sequences into one or more first bit sequences that must be transmitted and one or more second bit sequences that can be decoded without being transmitted. The communication device may also output multiple bit sequences consisting of one or more first bit sequences and one or more third bit sequences selected from the one or more second bit sequences.

[0114] In the first encoding process, processing is performed using a predetermined error correction encoding scheme. Figure 11 shows an example of the first encoding process. First, the communication device divides one bit sequence (one source bit sequence) into multiple source bit sequences. Then, the communication device generates multiple parity bit sequences by applying error correction encoding to the multiple source bit sequences. For example, the communication device generates multiple parity bit sequences by sequentially performing error correction encoding on multiple bit sequences, each consisting of two source bit sequences. Then, the communication device generates multiple output bit sequences by adding the multiple parity bit sequences to the multiple source bit sequences. Note that the parity bit sequences added to the multiple source bit sequences do not necessarily have to be all of the generated parity bit sequences. The communication device may add one or more parity bit sequences selected from the multiple parity bit sequences to the multiple source bit sequences.

[0115] Note that the example shown in Figure 11 is merely one example, and the first encoding process is not limited to the example shown in Figure 11. For example, the error correction encoding scheme may be one in which, when a predetermined bit sequence is input, the encoded bit sequence is output instead of just the parity bit sequence.

[0116] The error correction coding scheme used in the first coding process (hereinafter also referred to as the first error correction coding scheme) is preferably an error correction coding scheme belonging to categories such as Erasure Codes, Rateless Codes, or Fountain Codes. Alternatively, the error correction coding scheme used in the first coding process is preferably an error correction coding scheme that encodes multiple bit sequences by linear synthesis or XOR synthesis. Examples of error correction coding schemes that are expected to be used in the first coding process are shown below in (A1) to (A11). Of course, the error correction coding scheme used in the first coding process is not limited to the following examples.

[0117] (A1) Erasure correction code (A2) Rateless coding (A3)Fountain code (A4)Tornado code (A5)LT codes (Luby Transform Codes) (A6) Raptor code (A7)RaptorQ code (A8)LDPC codes (Low Density Parity Check Codes) (A9)BCH code (A10)RS codes (Reed Solomon Codes) (A11)XOR Codes (eXclusive OR Codes)

[0118] (B) Second encoding process Figure 12 is a diagram illustrating the second encoding process. In the second encoding process, one bit sequence (data sequence) is generated from one bit sequence (data sequence). Specifically, the communication device generates the output bit sequence by adding a parity sequence to the input bit sequence (data sequence). Note that the example shown in Figure 12 is just one example, and the second encoding process is not limited to the example shown in Figure 12.

[0119] The error correction coding scheme used in the second coding process (hereinafter also referred to as the second error correction coding scheme) is preferably one that belongs to a category such as convolutional codes, turbo codes, LDPC codes, or polar codes. Examples of error correction coding schemes that are expected to be used in the second coding process are shown below in (B1) to (B4). Of course, the error correction coding scheme used in the second coding process is not limited to the examples below.

[0120] (B1) Convolutional code (B2) Turbo code (B3)LDPC code (B4) Polar code

[0121] <3-1-3. Example of Encoding Procedure> Next, an example of the coding procedure of this embodiment will be described. Figure 13 is a sequence diagram showing an example of the coding procedure. Note that the example procedure shown in Figure 13 is merely an example, and this embodiment is not limited to this example procedure. Also, although Figure 13 shows downlink communication from base station 20 to terminal device 40, the technology disclosed in this embodiment can also be applied to other communications (for example, uplink communication from terminal device 40 to base station 20). The following describes an example of the coding procedure of this embodiment with reference to the sequence diagram in Figure 13.

[0122] First, the terminal device 40 notifies the base station 20 of the cell to which it is connected of information about its terminal capabilities (step S101). This information includes information about the capabilities of the first coding and the capabilities of the second coding. The terminal device 40 may notify this terminal capability information during or after the initial access procedure. For this notification, at least one of the following physical channels may be used: a Physical Random Access Channel (PRACH), a Physical Uplink Control Channel (PUCCH), and a Physical Uplink Shared Channel (PUSCH).

[0123] The base station 20 notifies terminal devices 40 connected to the cell it manages of quasi-static control information, including information regarding the first and second encodings (step S102). This quasi-static control information may be cell-specific control information. The base station 20 may notify this quasi-static control information during or after the initial connection procedure. The base station 20 may also notify this control information as part of an RRC procedure, such as RRC Signaling, RRC Configuration, or RRC Reconfiguration. The base station 20 may also notify terminal devices 40 of this control information periodically. At least one of the following physical channels may be used to notify this control information: a Physical Broadcast Channel (PBCH), an Enhanced Physical Downlink Control Channel (EPDCCH), and a Physical Downlink Shared Channel.

[0124] When terminal device 40 receives quasi-static control information, it sets up the encoding based on the information regarding the first encoding and the second encoding contained in the received control information (step S103).

[0125] Subsequently, when downlink communication occurs from the base station 20 to the terminal device 40, the base station 20 transmits dynamic control information to the terminal device 40. Examples of cases in which downlink communication occurs include when the terminal device 40 requests data download (pull) or when push data is generated to the terminal device 40. This dynamic control information may be terminal-specific (UE-specific) control information or terminal group-specific (UE-group-specific) control information. Here, a terminal group is, for example, a group of one or more terminal devices 40 that are the destinations when the downlink communication is multicast or broadcast.

[0126] Furthermore, dynamic control information may include various types of information, such as information about the wireless resources used for downlink communication. For example, dynamic control information may include information about various resources for allocating downlink communication to the target terminal device 40 (terminal device 40 group). More specifically, dynamic control information may include, for example, the following information (1) to (8).

[0127] (1) Frequency resources (e.g., Resource Block, Subcarrier, Subcarrier Group, etc.) (2) Time resources (e.g., subframes, slots, mini-slots, symbols, etc.) (3) Spatial resources (e.g., antenna, antenna port, spatial layer, spatial stream, etc.) (4) Non-orthogonal resources related to specified communications (e.g., NOMA (Non-orthogonal Multiple Access), MUST (Multiuser Superposition Transmission), IDMA (Interleave Division Multiple Access), CDMA (Code Division Multiple Access), etc.) (e.g., power resources, interleaving patterns, scrambling patterns, spreading patterns, etc.) (5) Information regarding the modulation order and the coding rate of the second coding (e.g., MCS (Modulation and Coding Set)) (6) Error correction coding scheme used in the first coding (7) Information regarding the coding rate of the first coding (8) Settings related to ARQ / HARQ (e.g., NDI (New Data Indicator), RV (Redundancy Version), etc.)

[0128] Upon receiving this dynamic control information, the terminal device 40 configures itself to prepare for proper reception of downlink communication according to that control information (step S105).

[0129] Next, the base station 20 performs a first encoding, a second encoding, and modulation on the downlink communication data to the terminal device 40 to match the control information notified to the terminal device 40 (step S106). The base station 20 transmits the encoded and modulated data to the terminal device 40 (step S107).

[0130] When the terminal device 40 receives data from the base station 20, it performs various processes (reception processing, demodulation processing, and decoding processing) including first and second encoding according to the settings specified in the control information (step S107). Then, the terminal device 40 sends an ACK or NACK back to the base station 20 depending on whether the data decoding was successful or unsuccessful. It is also desirable for the terminal device 40 to change the settings for ARQ / HARQ processing depending on whether the data decoding was successful or unsuccessful. For example, if decoding fails, it is desirable for the terminal device 40 to store the decoding result or data in the process of decoding (soft decision value, log-likelihood ratio (LLR), etc.) in memory in order to retransmit and combine the next HARQ. In the example in Figure 13, the terminal device 40 has failed to decode and performs ARQ / HARQ processing (step S109) and sends a NACK back to the base station 20 (step S110).

[0131] The base station 20 performs the next necessary processing according to the response (ACK / NACK) received from the terminal device 40. For example, if a NACK is received, preparations are made for retransmission of the ARQ / HARQ (step S111). These preparations for retransmission include selecting the RV, selecting the MCS, and selecting the radio resource. If an ACK is received from the terminal device 40, it means that the target data was transmitted and received without problems, so the communication of the next new data is initiated.

[0132] The base station 20 proceeds to retransmit or perform downlink communication of new data according to the ARQ / HARQ processing corresponding to the above response (ACK / NACK). To this end, the base station 20 notifies the target terminal device 40 of dynamic control information again and performs downlink communication according to its settings.

[0133] In the example shown in Figure 13, the base station 20 receives a NACK from the terminal device 40 (step S110), performs ARQ / HARQ processing (step S111), and again notifies the terminal device 40 of dynamic control information (step S112). Upon receiving this dynamic control information, the terminal device 40 makes settings to prepare for proper reception of downlink communication according to the control information (step S113). The base station 20 performs first encoding, second encoding, and modulation on the downlink communication data to the terminal device 40 to match the control information notified to the terminal device 40 (step S114), and then retransmits the encoded and modulated data to the terminal device 40 (step S115).

[0134] Then, the terminal device 40 synthesizes data based on the retransmitted signal (step S116), and performs various processes (reception processing, demodulation processing, and decoding processing) on ​​the synthesized data, including first encoding and second encoding, according to the settings specified in the control information (step S117). In the example in Figure 13, the terminal device 40 has succeeded in decoding at this point, performs ARQ / HARQ processing (step S118), and sends an ACK back to the base station 20 (step S110).

[0135] Upon receiving the ACK, base station 20 performs ARQ / HARQ processing and then moves on to communicating the next new data.

[0136] <3-2. Details of the communication system's operation> Next, the operation of communication system 1 will be described in detail.

[0137] While the introduction of packet duplication improves communication reliability, it significantly reduces frequency utilization efficiency because the same data is transmitted on multiple channels. The communication device of this embodiment generates multiple bit sequences with different content by applying a first encoding process based on a first error correction coding scheme to the transmitted data sequence, and distributes and transmits these multiple bit sequences on multiple channels, thereby achieving high frequency utilization efficiency while maintaining communication reliability. The following describes specific methods for achieving this.

[0138] <3-2-1. Overview of Signal Processing> First, let's explain the overall signal processing in this embodiment.

[0139] Figure 14 shows an overview of the signal processing in this embodiment. The signal processing in this embodiment will be explained in detail using Figure 14. The transmitting communication device divides a single data unit into multiple source bit blocks. Here, the single data unit corresponds to one bit sequence (transmitted data sequence) shown in Figure 11, and the multiple source bit blocks correspond to multiple source bit sequences shown in Figure 11. Subsequently, the transmitting communication device generates multiple encoded bit blocks by applying a first encoding to the source bit blocks. The encoded bit blocks correspond to the multiple bit sequences shown in Figure 11. Then, the transmitting communication device distributes the generated encoded bit blocks to multiple available independent channels and transmits them to the receiving communication device. The receiving communication device decodes the single data unit using the bit blocks received from each independent channel.

[0140] Here, a data unit may be, for example, a PDU (Protocol Data Unit) or SDU (Service Data Unit) handled in the PDCP layer, RLC layer, or MAC layer of the 3GPP standard. A data unit may consist of multiple data units, or it may consist of a single data unit that has been divided. Furthermore, a data unit may be defined at the CW (Codeword) level of the PHY layer.

[0141] The overall picture of signal processing has been explained above, but the processes that are elements of this embodiment (bit block division, encoding, and distribution) will now be explained in detail.

[0142] <3-2-2. Bit Block Unit Division> The transmitting communication device divides the data unit into bit blocks of arbitrary size. Here, a bit block is a group of bits generated by dividing the data unit into multiple parts. The name "bit block" is merely a temporary designation in this embodiment, and it may be called by other names, such as "symbol." In the following description, the divided bit blocks will be referred to as source bit blocks.

[0143] A bit block is generated by dividing a single data unit. The size of the bit block is determined based on prior information. If the transmitting communication device is a terminal device 40, the prior information may be, for example, information transmitted by the base station 20 to the terminal device 40 as quasi-static or dynamic control information. The prior information may include at least one of the following: QoS, 5QI, MCS, header information added at higher layers, and frequency resource amount information used at the physical layer. Of course, the prior information is not limited to these.

[0144] It is desirable that the size of each generated bit block is equal. Of course, the size of each bit block does not have to be equal. If the first encoding process requires bit blocks of the same size, the communication device divides the data unit so that the sizes of multiple bit blocks are equal. In this case, if the bit block size determined by prior information is not an integer multiple of the number of bits in the data unit, the communication device may make the size of each bit block uniform as shown below.

[0145] First, the communication device separates bit blocks from the data unit until the quotient between the data unit and the bit block size is an integer value that does not exceed the number of bits in the data unit. After this processing, the communication device zero-paddings the remaining bits of the data unit until they reach the bit block size. This generates multiple bit blocks of equal size from the data unit. Note that the method for making each bit block size uniform is not limited to this.

[0146] <3-2-3. Encoding> Next, the transmitting communication device encodes the multiple bit blocks generated by dividing the data unit. The encoding process performed here corresponds to the first encoding process described above. In the following description, each of the multiple bit blocks generated after the first encoding process will be referred to as an encoded bit block. The name "encoded bit block" is merely a temporary designation in this embodiment, and it may be referred to by other names. For example, an encoded bit block may be referred to as an encoded bit sequence, or simply as a bit sequence.

[0147] Multiple encoded bit blocks may consist of source bit blocks and parity bit blocks. Figure 15 shows a specific example of the overall signal processing shown in Figure 14. In the example in Figure 15, nine encoded bit blocks consist of six source bit blocks and three parity bit blocks. Note that multiple encoded bit blocks do not necessarily need to contain source bit blocks, as long as the receiving communication layer can ultimately decode the data data unit. For example, each encoded bit block may be a bit block containing a mixture of parity bit sequences and source bit sequences.

[0148] Here, the source bit block refers to the group of bit blocks generated in the data unit partitioning process before encoding, among the encoded bit blocks. The parity bit block refers to the parity generated in the error correction encoding process included in the first encoding process. The names source bit block and parity bit block are merely temporary designations in this embodiment, and these names may be referred to by other names. For example, the source bit block may be replaced with the source bit sequence. Similarly, the parity bit block may be replaced with the parity bit sequence.

[0149] The number of parity bit blocks to be generated may be determined based on information notified in advance. If the transmitting communication device is a terminal device 40, the information notified in advance may be, for example, information transmitted by the base station 20 to the terminal device 40 as quasi-static or dynamic control information. Here, the information notified in advance may include at least one of the following: QoS, 5QI, MCS, and information included in the header added at the upper layer.

[0150] Each encoded bit block may be assigned a unique ID to identify it, enabling the receiving communication device to correctly decode it. This ID may be defined, for example, as a sequential number for a group of encoded bit blocks generated by a single first encoding process. This ID may also be defined as overhead added during the first encoding process. Alternatively, this ID may be defined in conjunction with other information defined by 3GPP (for example, an SN (Sequence Number) added as a header in higher-layer processing). Here, the ID is a descriptive name and can be replaced with other identifying information of the same concept.

[0151] Multiple encoded bit blocks are given a function that allows for error detection for each bit block. This function may be, for example, a CRC (Cyclic Redundancy Check) or a checksum. This error detection function is added in one of the layers, such as the PDCP layer, RLC layer, or MAC layer, provided that the first encoding process is performed later.

[0152] <3-2-4. Distribution> Next, the transmitting communication device distributes the multiple encoded bit blocks to the available channels. The transmitting communication device may divide the multiple encoded bit blocks to be transmitted equally among the number of available channels and assign the same number of encoded bit blocks to each channel. Alternatively, the transmitting communication device may obtain the status of the available channels as prior information and distribute the multiple encoded bit blocks to the channels based on that information.

[0153] For example, suppose a transmitting communication device transmits multiple encoded bit blocks using a channel A in good condition and a channel B in poor condition. Here, a channel in good condition may be, for example, a channel whose loss rate is less than a predetermined threshold, or a channel whose error rate is less than a predetermined threshold. A channel in poor condition may be, for example, a channel whose loss rate is greater than a predetermined threshold, or a channel whose error rate is greater than a predetermined threshold.

[0154] In this case, channel A can be modulated with a higher order at the physical layer, allowing it to allocate more encoded bit blocks. On the other hand, channel B has a poor channel state, so it is undesirable to apply higher-order modulation to it. Therefore, the transmitting communication device is configured to apply higher-order modulation to channel A than to channel B, and also allocates more encoded bit blocks to channel A than to channel B.

[0155] Furthermore, the transmitting communication device may perform distribution processing using information other than that mentioned above. An example of other information is the amount of available frequency resources. For example, the transmitting communication device may acquire information on the amount of resources available for transmission for each of the multiple channels. Then, based on the acquired resource amount information, the transmitting communication device distributes multiple coded bit blocks to the multiple channels. For example, the transmitting communication device may distribute many coded bit blocks to channels that have many resources available.

[0156] Furthermore, the transmitting communication device may distribute multiple encoded bit blocks to multiple channels based on the delay amount until transmission for each channel. For example, consider the case where communication is performed using dual connectivity. Here, suppose two independent channels are created using a main gNB and a secondary gNB. When multiple encoded bit blocks are transmitted using the channel consisting of the secondary gNB and base station 20 (main gNB), some of the multiple encoded bit blocks need to be transmitted from the main gNB to the secondary gNB. Therefore, the inter-base station communication between the main gNB and the secondary gNB becomes a processing delay, resulting in a difference in the transmission start time of the encoded bit blocks between the main gNB and the secondary gNB.

[0157] Therefore, the transmitting communication device may distribute bit blocks to each independent channel, taking into account the delay caused by communication between base stations. For example, the transmitting communication device distributes fewer bit blocks to channels with high delays than to channels with low delays. When distribution is performed considering delays, the amount of delay may be notified in advance from, for example, the management device 10. Alternatively, the transmitting communication device may perform the distribution process with the amount of delay as a fixed value.

[0158] The method of distributing the encoded bit blocks is not limited to the above. The transmitting communication device may distribute multiple encoded bit blocks to multiple channels by combining multiple methods, including at least one of the above methods.

[0159] <3-3. Sequence Examples (Basic Form)> Next, we will describe an example of the communication processing sequence in this embodiment. First, we will describe the basic sequence example. Figure 16 is a diagram showing an example of the communication processing sequence (basic form) in this embodiment.

[0160] The transmitting communication device could be, for example, one or more base stations 20, one or more relay stations 30, or one or more terminal devices 40. On the other hand, the receiving communication device could be, for example, one terminal device 40 or one base station 20. In the example in Figure 16, it is assumed that two independent channels are used to transmit the encoded bit block, but the number of channels used is not limited to two. Also, in the example in Figure 16, the base station 20 is the transmitting communication device and the terminal device 40 is the receiving communication device, but the transmitting and receiving communication devices are not limited to this example. For example, the base station 20 could be the receiving communication device and the terminal device 40 could be the transmitting communication device.

[0161] The following processes are executed, for example, by the control unit 23 of the base station 20 and the control unit 43 of the terminal device 40. The communication process of this embodiment will be described below with reference to the sequence example in Figure 16.

[0162] First, the acquisition unit 233 of the base station 20 acquires information necessary for encoding (information related to the decoding process), including information related to bit blocks. Then, the base station 20 determines the number of divisions and / or the number of bit blocks to be generated based on the acquired information (step S201). The information necessary for encoding may also be used to determine the following information (1) to (4).

[0163] (1) Encoding table used in the first encoding (2) Number of bit block divisions (3) Divided bit block size (4) Bit block distribution

[0164] The base station 20 may also obtain this information from, for example, QoS, 5QI, MCS, header information added in the upper layer, frequency resource amount information used in the physical layer, etc.

[0165] Furthermore, the transmitting communication device may obtain the information necessary for this encoding from the transmitting communication device. For example, unlike the example in Figure 16, suppose the transmitting communication device is a terminal device 40 and the receiving communication device is a base station 20. In this case, the acquisition unit 433 of the terminal device 40 may obtain the information necessary for encoding from the base station 20.

[0166] Next, the transmitting unit 232 of the base station 20 transmits the information necessary for decoding to the terminal device 40 (step S202). The acquiring unit 233 of the terminal device 40 acquires the information necessary for decoding from the base station 20. In this embodiment, it is assumed that the base station 20 has previously communicated the information necessary for decoding to the terminal device 40. The information necessary for decoding includes, for example, the following (1) to (5).

[0167] (1) Encoding table used for encoding (2) Number of bit block divisions (3) Divided bit block size (4) Total number of source bit blocks (5) Number of bit blocks successfully received at the start of decoding

[0168] The base station 20 may, for example, add this information to the bit block as overhead, rather than transmitting it separately to the terminal device 40.

[0169] Next, the generation unit 234 of the base station 20 divides the data units and encodes the bit blocks generated by the division, as explained using, for example, Figure 14. Then, the distribution unit 235 of the base station 20 distributes the encoded bitbooks, as explained using, for example, Figure 14 (step S203). Here, the base station 20 may add overhead to multiple bitbooks on a bit block basis. The overhead includes, for example, the following information (1) to (3).

[0170] (1) Error detection function (e.g., CRC, checksum) (2) ID (3) Encoding table

[0171] Note that base station 20 is not necessarily required to include all of the above information as overhead. Base station 20 may also include other information as overhead.

[0172] Next, the transmitting unit 232 of the base station 20 transmits data including encoded bit blocks using multiple channels (step S204). An example of the data transmitted here is transport block data that has been processed by the physical layer (for example, second encoding has been performed). This transmitted data may contain multiple encoded bit blocks. Alternatively, the transmitted data may contain parts of multiple encoded bit blocks.

[0173] The receiving unit 231 of the terminal device 40 receives data containing encoded bit blocks from multiple channels. The terminal device 40 then performs processing on the received data at the physical layer (for example, a second decoding process) and uses the error detection function attached to the encoded bit block to determine whether or not the encoded bit block was received correctly. At this time, the terminal device 40 may perform this error detection independently for each channel before storing the encoded bit block in the buffer.

[0174] If an error is detected in the encoded bit block, the terminal device 40 discards that encoded bit block. If the encoded bit block is received correctly, the terminal device 40 stores that encoded bit block in a buffer.

[0175] Next, the start determination unit 436 of the terminal device 40 determines whether the start condition for the decoding process (hereinafter referred to as the decoding start condition) has been met (step S205). The decoding start condition may be a condition determined based on the information necessary for the encoding described above (information related to the decoding process). For example, at least one of the following (C1) to (C2) can be assumed as the decoding start condition.

[0176] (C1) If the number of encoded bit blocks equal to or greater than the number of source bit blocks notified in advance is successfully received. In the case of the first error correction coding scheme (especially the case of loss correction coding), sufficient performance cannot be obtained by decoding using coding bit blocks less than or equal to the number of source bit blocks. Therefore, defining the decoding start condition as (C1) is effective from the standpoint of efficiency. In this case, the transmitting communication device may notify the receiving communication device of the number of source bit blocks. This information may be notified by the "information necessary for decoding" described above, or by the overhead per bit block.

[0177] (C2) When a predetermined number (threshold) of encoded bit blocks are stored on the receiving side. In the first error correction coding scheme (especially in the case of loss correction coding), the transmitting communication device can roughly estimate the decoding gain based on the number of coded bit blocks received by the receiving device. The transmitting communication device may determine a threshold number that triggers decoding based on the estimated decoding gain. The receiving communication device may then notify the transmitting communication device of this threshold number.

[0178] Note that the decryption start conditions may include conditions other than those listed above. The receiving communication device may determine whether the decryption start conditions have been met by combining multiple conditions, including at least one of the above conditions. Furthermore, the receiving communication device may change the conditions used depending on the type and importance of the received data. For example, if the received data is control data, the receiving communication device may use the condition (C2) above to determine whether the decryption start conditions have been met, and if the received data is user data, the receiving communication device may use the condition (C1) above to determine whether the decryption start conditions have been met. The type and importance of the data may be determined by the communication device based on 5QI or QoS, or it may be set independently by the communication device.

[0179] If the decoding start condition is met, the decoding unit 437 of the terminal device 40 starts the first decoding process (step S206). At this time, if the decoding start criterion is met, the decoding unit 437 starts the first decoding process even before the reception of all of the multiple encoded bit blocks is complete.

[0180] Then, the decryption determination unit 438 of the terminal device 40 determines whether the decryption success conditions have been met (step S207). For example, at least one of the following (D1) to (D2) is assumed as the decryption success conditions. Of course, the decryption success conditions may also include conditions other than those listed below.

[0181] (D1) If the decoded data unit does not contain any errors The decoding determination unit 438 may define the condition for successful decoding as the absence of errors in the decoded data unit. If the condition for successful decoding is met, the receiving communication device may notify the transmitting communication device of the success of decoding. For example, the receiving communication device may notify the transmission communication device of success if no errors are detected in the decoded data unit. In order for the transmitting communication device to detect errors on a data unit basis, the transmitting communication device provides each data unit with a function that enables error detection before data unit division. This function is, for example, CRC.

[0182] (D2) When a predetermined number of successful reception bit blocks have accumulated in the buffer The decoding determination unit 438 may, even before actual decoding is successful, assume that the decoding success conditions have been met and issue a decoding success notification. For example, the decoding determination unit 438 may issue a decoding success notification when the number of successfully received encoded bit blocks reaches a predetermined number. In this case, the transmitting communication device may notify the receiving communication device of the above number in advance. This information may be notified by the "information necessary for decoding" described above, or by the overhead of each bit block.

[0183] Furthermore, the decoding success conditions may include conditions other than those listed above. The receiving communication device may determine whether the decoding success conditions have been met by combining multiple conditions, including at least one of the above conditions.

[0184] Furthermore, the receiving communication device may change the conditions used depending on the type and importance of the received data. For example, if the received data is control data, the receiving communication device may use the conditions in (D1) above to determine whether the decoding start condition has been met, and if the received data is user data, the receiving communication device may use the conditions in (D2) above to determine whether the decoding start condition has been met. The type and importance of the data may be determined by the communication device based on 5QI or QoS, or it may be set independently by the communication device.

[0185] If the decoding success conditions are not met, the start determination unit 436 of the terminal device 40 discards the output data during decoding and determines whether the restart conditions for the first decoding process (hereinafter referred to as the decoding restart conditions) have been met (step S208). The start determination unit 436 may also use the condition that the number of successfully received encoded bit blocks is greater than the number at the time of decoding failure as the decoding restart condition. The first encoding process yields better decoding gain the more bit blocks input during decoding. Therefore, if the number of successfully received encoded bit blocks is greater than the number at the time of decoding failure, decoding may succeed by attempting decoding again.

[0186] The start determination unit 436 may also monitor a buffer storing successfully received encoded bit blocks to determine whether the conditions for resuming decoding have been met. In this embodiment, the transmitting communication device continues to transmit encoded bit blocks until it receives a transmission success notification. Therefore, in this embodiment, it is assumed that the number of successfully received encoded bit blocks will increase even while the receiving communication device is performing reception processing and encoding processing.

[0187] If the conditions for resuming decoding are met, the decoding unit 437 of the terminal device 40 resumes the first decoding process (step S209). For example, if the number of successfully received encoded bit blocks is greater than the number of times decoding failed, the decoding unit 437 executes the first decoding process using the encoded bit blocks stored in the buffer.

[0188] Then, the decoding determination unit 438 of the terminal device 40 determines again whether or not the decoding success conditions have been met (step S210). If the decoding success conditions have been met, the transmission unit 232 of the terminal device 40 sends a decoding success notification to the base station 20 (step S211). This success notification is a notification to control the bit block transmission on the transmitting side.

[0189] When base station 20 receives a notification of successful decoding, it stops generating and transmitting coded bit blocks (step S212).

[0190] <3-4. Sequence Example (Modification 1)> Next, we will describe a modified version of the sequence example (basic form) shown in Figure 16. Figure 17 shows a sequence example (modified version 1) of the communication processing in this embodiment.

[0191] In the example shown in Figure 17, the receiving communication device detects errors on a per-encoded bit block basis and then sends a response (ACK / NACK) to the transmitting communication device indicating whether or not each encoded bit block was received correctly. This allows the transmitting communication device to decide whether or not to continue transmitting the encoded bit block without waiting for notification of the decoding results from the receiving communication device.

[0192] In the example in Figure 17, similar to the example in Figure 16, it is assumed that two independent channels are used to transmit the encoded bit block, but the number of channels used is not limited to two. Also, in the example in Figure 17, similar to the example in Figure 16, the base station 20 is the transmitting communication device and the terminal device 40 is the receiving communication device, but the transmitting and receiving communication devices are not limited to this example. For example, the base station 20 may be the receiving communication device and the terminal device 40 may be the transmitting communication device.

[0193] The following processes are executed, for example, by the control unit 23 of the base station 20 and the control unit 43 of the terminal device 40. The communication process of this embodiment will be described below with reference to the sequence example in Figure 17.

[0194] First, the acquisition unit 233 of the base station 20 acquires the information necessary for encoding. Then, the base station 20 determines the number of divisions and / or the number of bit blocks to generate based on the acquired information (step S301). Then, the transmission unit 232 of the base station 20 transmits the information necessary for decoding to the terminal device 40 (step S302). The acquisition unit 233 of the terminal device 40 acquires the information necessary for decoding from the base station 20.

[0195] Next, the generation unit 234 of the base station 20 divides the data unit and encodes the bit blocks generated by the division. Then, the distribution unit 235 of the base station 20 distributes the encoded bitbooks (step S303). Then, the transmission unit 232 of the base station 20 transmits the data including the encoded bit blocks using multiple channels (step S304).

[0196] The receiving unit 431 of the terminal device 40 receives data including encoded bit blocks from multiple channels. The terminal device 40 then performs a second decoding process on the received data and uses an error detection function attached to the encoded bit block to determine whether the encoded bit block was received correctly. The transmitting unit 232 of the terminal device 40 then transmits an ACK / NACK based on the determination result (step S306). An ACK is transmitted if the encoded bit block was received correctly, and a NACK is transmitted if it was not received correctly. The transmitting unit 232 may transmit an ACK / NACK each time the second decoding process is performed on the encoded bit block. The receiving unit 231 of the base station 20 receives an ACK / NACK from the terminal device 40. If the encoded bit block was received correctly, the terminal device 40 stores the encoded bit block in a buffer.

[0197] Next, the start determination unit 236 of the base station 20 determines whether the decoding start condition has been met in the terminal device 40 (step S306). For example, the base station 20 shares information about the decoding start condition with the terminal device 40 in advance. The base station 20 then determines whether the decoding start condition has been met based on the ACK information received from the terminal device 40. For example, the base station 20 may determine whether the decoding start condition has been met by counting the number of ACKs received from the terminal device 40. If the decoding start condition is met, the transmission unit 232 of the base station 20 stops transmitting data (step S307).

[0198] Furthermore, the start determination unit 436 of the terminal device 40 also determines whether the decryption start condition has been met (step S308). If the decryption start condition has been met, the decryption unit 437 of the terminal device 40 starts the first decryption process (step S309). Then, the decryption determination unit 438 of the terminal device 40 determines whether the decryption success condition has been met (step S310).

[0199] If the decoding success conditions are not met, the terminal device 40 sends a decoding failure notification (step S311). When the base station 20's transmitter 432 receives the failure notification, it resumes transmitting the encoded bit block (step S312). When the terminal device 40 receives the data, it determines whether or not the encoded bit block was received correctly. Then, the terminal device 40's transmitter 232 sends an ACK / NACK based on the determination result (step S313).

[0200] Furthermore, even if the transmitter 432 of the base station 20 receives an ACK, it does not need to stop transmitting the encoded bit block when resuming transmission of the encoded bit block. Of course, the transmitter 432 may stop transmitting the encoded bit block when it receives an ACK.

[0201] The start determination unit 436 of the terminal device 40 determines whether the decryption restart condition has been met (step S314). If the decryption restart condition has been met, the decryption unit 437 of the terminal device 40 restarts the first decryption process (step S315).

[0202] Then, the decoding determination unit 438 of the terminal device 40 determines again whether or not the decoding success conditions have been met (step S316). If the decoding success conditions have been met, the transmission unit 232 of the terminal device 40 sends a decoding success notification to the base station 20 (step S317).

[0203] When base station 20 receives a notification of successful decoding, it stops generating and transmitting coded bit blocks (step S318).

[0204] <3-5. Sequence Example (Modification 2)> Next, we will describe other variations of the sequence example (basic form) shown in Figure 16. Figure 18 shows a sequence example (variation 2) of the communication processing in this embodiment.

[0205] In the example shown in Figure 18, the communication device considers the decryption success condition to be met and sends a decryption success notification before actual decryption is successful. Specifically, as shown in (D2) above, the receiving communication device sends a decryption success notification to the transmitting terminal device when the number of successfully received encoded bit blocks reaches a predetermined number. This allows the transmitting communication device to decide whether or not to continue transmitting encoded bit blocks without waiting for notification of the decryption process result from the receiving communication device. In this example, the receiving communication device does not necessarily need to perform error detection on a data unit basis after decryption. Therefore, in the example shown in Figure 18, the receiving communication device may omit the provision of error detection on a data unit basis. Note that the communication device may decide whether or not to omit the provision of error detection depending on the type and importance of the transmitted data.

[0206] If the data being handled does not require high reliability, the method shown in Figure 18 may be chosen instead of the method shown in Figure 16. By using the method shown in Figure 18, the communication device can ignore delays caused by retransmission and decoding processes, enabling lower-latency communication. Whether or not the data requires high reliability may be determined based on the type and importance of the data. The type and importance of the data may be determined by the communication device based on 5QI or QoS, or by the communication device using its own criteria.

[0207] In the example in Figure 17, similar to the example in Figure 16, it is assumed that two independent channels are used to transmit the encoded bit block, but the number of channels used is not limited to two. Also, in the example in Figure 17, similar to the example in Figure 16, the base station 20 is the transmitting communication device and the terminal device 40 is the receiving communication device, but the transmitting and receiving communication devices are not limited to this example. For example, the base station 20 may be the receiving communication device and the terminal device 40 may be the transmitting communication device.

[0208] The following processes are executed, for example, by the control unit 23 of the base station 20 and the control unit 43 of the terminal device 40. The communication process of this embodiment will be described below with reference to the sequence example in Figure 17.

[0209] First, the acquisition unit 233 of the base station 20 acquires the information necessary for encoding. Then, the base station 20 determines the number of divisions and / or the number of bit blocks to generate based on the acquired information (step S401). Then, the transmission unit 232 of the base station 20 transmits the information necessary for decoding to the terminal device 40 (step S402). The acquisition unit 233 of the terminal device 40 acquires the information necessary for decoding from the base station 20.

[0210] Next, the generation unit 234 of the base station 20 divides the data units and encodes the bit blocks generated by the division. Then, the distribution unit 235 of the base station 20 distributes the encoded bitbooks (step S403). Then, the transmission unit 232 of the base station 20 transmits the data including the encoded bit blocks using multiple channels (step S404).

[0211] The receiving unit 231 of the terminal device 40 receives data containing encoded bit blocks from multiple channels. The terminal device 40 then performs a second decoding process on the received data and uses the error detection function attached to the encoded bit block to determine whether the encoded bit block was received correctly. The terminal device 40 then stores the correctly received encoded bit blocks in a buffer.

[0212] Next, the start determination unit 436 of the terminal device 40 determines whether the decryption start condition has been met (step S405). If the decryption start condition has been met, the transmission unit 432 of the terminal device 40 transmits a notification to the base station 20 indicating that the decryption start condition has been met (hereinafter referred to as the achievement notification) (step S406). If the decryption start condition has been met, the transmission unit 432 may transmit a decryption success notification to the base station 20 instead of the achievement notification, regardless of whether the decryption process has been completed or not. The base station 20 may consider the achievement notification as a decryption success notification.

[0213] The terminal device 40 may change the transmission conditions for the decryption success notification depending on the type and importance of the received data. For example, if the received data is control data, the transmission unit 432 of the terminal device 40 will send a decryption success notification to the base station 20 when the decryption is actually successful (when the decryption success conditions are met). On the other hand, if the received data is user data, the transmission unit 432 will send a decryption success notification to the base station 20 when the decryption start conditions are met, regardless of whether the decryption process has been completed or not. The type and importance of the data may be determined by the communication device based on 5QI or QoS, or it may be set independently by the terminal device 40 or the base station 20.

[0214] When the transmitting unit 232 of the base station 20 receives an achievement notification (or a decoding success notification), it stops transmitting data (step S407).

[0215] Furthermore, once the decryption start condition is met, the decryption unit 437 of the terminal device 40 starts the first decryption process (step S408). Then, the decryption determination unit 438 of the terminal device 40 determines whether the decryption success condition has been met (step S409).

[0216] If the decoding success conditions are not met, the terminal device 40 issues a decoding failure notification (step S410). When the base station 20's transmitter 432 receives the failure notification, it resumes transmitting the encoded bit block (step S411). Upon receiving the data, the terminal device 40 determines whether or not the encoded bit block was received correctly. The terminal device 40 then stores the correctly received encoded bit block in a buffer.

[0217] The start determination unit 436 of the terminal device 40 determines whether the decryption restart condition has been met (step S412). If the decryption restart condition has been met, the transmission unit 432 of the terminal device 40 sends a notification that the decryption restart condition has been met to the base station 20. When the transmission unit 232 of the base station 20 receives the notification, it stops transmitting data (step S414).

[0218] Furthermore, if the decryption restart condition is met, the decryption unit 437 of the terminal device 40 restarts the first decryption process (step S415). Then, the decryption determination unit 438 of the terminal device 40 determines again whether or not the decryption success condition has been met (step 416). If the decryption success condition is met, the transmission unit 232 of the terminal device 40 sends a decryption success notification to the base station 20 (step S417).

[0219] <3-6. Sequence Example (Modification 3)> Next, we will describe other variations of the sequence example (basic form) shown in Figure 16. Figure 19 shows a sequence example (variation 3) of the communication processing in this embodiment.

[0220] In the example shown in Figure 19, the receiving communication device stores all received bit blocks from all channels in a buffer before performing error detection on a per-encoded bit block basis. This allows bit block correctness determination to be performed without independent channel-by-channel testing, thus simplifying the configuration, for example, when the receiving communication device sends ACK / NACK on a per-encoded bit block basis.

[0221] First, the acquisition unit 233 of the base station 20 acquires the information necessary for encoding. Then, the base station 20 determines the number of divisions and / or the number of bit blocks to generate based on the acquired information (step S501). Then, the transmission unit 232 of the base station 20 transmits the information necessary for decoding to the terminal device 40 (step S502). The acquisition unit 233 of the terminal device 40 acquires the information necessary for decoding from the base station 20.

[0222] Next, the generation unit 234 of the base station 20 divides the data unit and encodes the bit blocks generated by the division. Then, the distribution unit 235 of the base station 20 distributes the encoded bitbooks (step S503). Then, the transmission unit 232 of the base station 20 transmits the data including the encoded bit blocks using multiple channels (step S504). Note that the transmission unit 232 of the base station 20 may transmit the same data repeatedly.

[0223] The receiving unit 231 of the terminal device 40 receives data containing encoded bit blocks from multiple channels. In this example sequence, the terminal device 40 stores the multiple encoded bit blocks sent from multiple channels into a single buffer before performing error detection. Specifically, the terminal device 40 temporarily stores the multiple encoded bit blocks contained in the multiple data received from each channel into a buffer. Then, the terminal device 40 performs a second decoding process on the data stored in the buffer and uses the error detection function attached to the encoded bit block to determine whether or not the encoded bit block was received correctly (step S505). If an error is detected in the encoded bit block, the terminal device 40 discards that encoded bit block.

[0224] Next, the start determination unit 436 of the terminal device 40 determines whether the decryption start condition has been met (step S506). If the decryption start condition has been met, the decryption unit 437 of the terminal device 40 starts the first decryption process (step S507). Then, the decryption determination unit 438 of the terminal device 40 determines whether the decryption success condition has been met (step S508).

[0225] If the decryption success condition is not met, the start determination unit 436 of the terminal device 40 determines whether the decryption restart condition has been met (step S509). If the decryption restart condition has been met, the decryption unit 437 of the terminal device 40 restarts the first decryption process (step S510). Then, the decryption determination unit 438 of the terminal device 40 determines again whether the decryption success condition has been met (step 511). If the decryption success condition has been met, the transmission unit 232 of the terminal device 40 sends a decryption success notification to the base station 20 (step S512).

[0226] When base station 20 receives a notification of successful decoding, it stops generating and transmitting coded bit blocks (step S513).

[0227] <<4. Reliability Evaluation>> Next, the results of the reliability evaluation of the technology disclosed in this embodiment will be explained. Here, a comparison of the configuration using this embodiment with a configuration using a conventional method will be shown.

[0228] The frequency utilization efficiency of the communication using the configuration of this embodiment was evaluated by simulation. In this simulation, the superiority of the method using the first encoding process (upper layer FEC) of this embodiment is verified by simulation. The conventional technology used for comparison is PDCP duplication. In particular, in this verification, we focused on the improved frequency utilization efficiency and constructed a simulation that would allow us to see the results.

[0229] Figure 20 shows a schematic diagram of the constructed simulation. This time, focusing on improving the frequency utilization efficiency of the proposed method, a simulation was constructed that extracted only the elements necessary for verification from the 5G protocol. Hereafter, the device used to run the simulation will simply be referred to as the information processing device.

[0230] First, let's explain the conventional method. First, the information processing device creates a data block of arbitrary length using randomly generated bits. Then, the information processing device duplicates the data block. The information processing device then divides both data blocks into arbitrary numbers of equal lengths using the same procedure. In this way, the information processing device creates an arbitrary number of bit blocks.

[0231] The created bit block and its copies pass through separate loss channels. The bit block loss rate is the same for each loss path, and this value is arbitrary. Bit blocks lost through the bit block loss channel are discarded immediately. For bit blocks that were not lost, the receiving end can determine which bit block was transmitted on each channel.

[0232] On the receiving end, decoding is performed. For multiple bit blocks sent on individual channels, if one of the bit blocks—the original bit block and its duplicate—is lost, but the other bit block is still present, the bit block is considered to have been received correctly. If this is successfully transmitted for all the bit blocks constituting the transmitted data block, the transmitted data block is considered to have been transmitted successfully. In other words, if the original bit block and its duplicate bit block, created from the transmitted data block, are lost simultaneously on their respective individual channels, the transmitted data block will be considered to have failed to transmit, regardless of the reception status of the other bit blocks.

[0233] On the other hand, in the proposed method, the information processing device first creates an arbitrary number of bit blocks for a transmission block composed of randomly generated bits. Then, it performs Raptor coding using the generated bit blocks. Raptor coding is one of the error correction coding schemes intended for use in the first coding process. The parameters of the Raptor coding used in this case follow IETF RFC5053. The parity bit block generated by coding passes through a different channel than the generated data block. At this time, the channel state and the handling of lost blocks are the same as in the conventional method, and similarly, the receiving side knows which bit block the received bit block is the transmitted bit block. The receiving side performs Raptor decoding using the bit blocks that were correctly received through each channel. If the transmitted data block is correctly decoded, the transmission is successful.

[0234] Figure 21 shows the specifications of this simulation. In this simulation, the transmit data block size was set to 100 bits, which was divided into 10-bit bit blocks. The channel loss rate was set to 10% and 0.1% per transmit block, respectively, by setting the loss rate per bit block.

[0235] This simulator verifies how many parity bit blocks are needed to achieve performance equivalent to that of conventional methods, based on the reliability obtained by those methods. If the proposed method achieves the same reliability as the conventional method, and the total required parity bit block length is shorter than the transmitted data block length, then the proposed method can be evaluated as having improved frequency utilization efficiency compared to the conventional method.

[0236] Figures 22 and 23 show the simulation results. Specifically, Figure 22 shows the results for the total number of transmitted bit blocks versus the data unit error rate when the loss rate is 10%. Figure 23 shows the results for the total number of transmitted bit blocks versus the data unit error rate when the loss rate is 0.1%. The total number of transmitted bit blocks is the sum of the source bit block count and the parity bit block count. The dashed line parallel to the horizontal axis shown in Figures 22 and 23 shows the data unit error rate achieved by the conventional method when the total number of bit blocks is 20 (10 transmitted data bit blocks + 10 duplicated transmitted source bit blocks).

[0237] Figures 22 and 23 show that the proposed method surpasses the reliability of conventional methods with 10 transmitted data bit blocks + 4 parity bit blocks, regardless of the channel loss rate. Furthermore, it can be confirmed that the decoding performance of the Raptor code used in this study significantly improves when 4 parity bit blocks arrive. This characteristic is mainly due to the adoption of IETF RFC 5053 as the configuration of the Raptor code. Note that the number of parity bit blocks required for decoding depends on the configuration of the first encoding process (upper layer FEC), so it is expected that this value will change if a different configuration is used.

[0238] <<5. Variation>> The above-described embodiment is merely an example, and various modifications and applications are possible.

[0239] For example, in the above-described embodiment, the transmitting communication device was a base station 20 and the receiving communication device was a terminal device 40, but the transmitting communication device and the receiving communication device are not limited to this example. For example, the transmitting communication device may be a terminal device 40 and the receiving communication device may be a base station 20. Alternatively, the transmitting communication device may be a terminal device 40 and the receiving communication device may be a terminal device 40. Alternatively, the transmitting communication device may be a base station 20 and the receiving communication device may be a base station 20. In addition, a relay station 30 may be included in either or both of the transmitting and receiving communication devices.

[0240] The control device that controls the management device 10, base station 20, relay station 30, and terminal device 40 in this embodiment may be implemented by a dedicated computer system or by a general-purpose computer system.

[0241] For example, a communication program for performing the above-described operations is stored in a computer-readable recording medium such as an optical disc, semiconductor memory, magnetic tape, or flexible disk and distributed. Then, for example, the control device is configured by installing the program on a computer and executing the above-described process. In this case, the control device may be an external device (e.g., a personal computer) of the management device 10, base station 20, relay station 30, or terminal device 40. Alternatively, the control device may be an internal device (e.g., control unit 13, control unit 23, control unit 33, or control unit 43) of the management device 10, base station 20, relay station 30, or terminal device 40.

[0242] Alternatively, the above communication program may be stored on a disk device provided by a server on a network such as the Internet, and made available for download to a computer. Furthermore, the above functions may be realized through the cooperation of an OS (Operating System) and application software. In this case, the parts other than the OS may be stored on a medium and distributed, or the parts other than the OS may be stored on a server device and made available for download to a computer.

[0243] Furthermore, among the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically by known methods. In addition, the processing procedures, specific names, and information including various data and parameters shown in the above document and drawings can be arbitrarily changed unless otherwise specified. For example, the various information shown in each figure is not limited to the information shown.

[0244] Furthermore, the components of each illustrated device are functionally conceptual and do not necessarily need to be physically configured as shown. In other words, the specific forms of distribution and integration of each device are not limited to those shown, and all or part of them can be functionally or physically distributed and integrated in any unit according to various loads and usage conditions. This distribution and integration configuration may also be performed dynamically.

[0245] Furthermore, the above-described embodiments can be combined as appropriate in areas where the processing content is not contradictory. Also, the order of each step shown in the flowchart of the above-described embodiments can be changed as appropriate.

[0246] Furthermore, for example, this embodiment can also be implemented as any configuration that makes up a device or system, such as a processor as a system LSI (Large Scale Integration), a module using multiple processors, a unit using multiple modules, or a set with additional functions added to a unit (i.e., a configuration of a part of a device).

[0247] In this embodiment, a system refers to a collection of multiple components (devices, modules (parts), etc.), regardless of whether all components are located in the same enclosure. Therefore, multiple devices housed in separate enclosures and connected via a network, and a single device containing multiple modules within a single enclosure, are both considered systems.

[0248] Furthermore, for example, this embodiment can adopt a cloud computing configuration in which a single function is shared and processed collaboratively by multiple devices via a network.

[0249] <<6. Conclusion>> As described above, according to one embodiment of the present disclosure, the communication device of this embodiment (for example, a base station 20 and a terminal device 40) performs wireless communication using multiple channels. The communication device generates multiple bit sequences with different contents by applying a predetermined encoding process based on a predetermined error correction coding scheme to the transmission data sequence. The communication device then distributes and transmits the multiple bit sequences to multiple channels. As a result, the communication device of this embodiment can achieve high frequency utilization efficiency while maintaining the reliability of communication.

[0250] Although the embodiments of this disclosure have been described above, the technical scope of this disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the gist of this disclosure. Furthermore, components from different embodiments and modifications may be combined as appropriate.

[0251] Furthermore, the effects described in each embodiment of this specification are merely illustrative and not limiting, and other effects may also occur.

[0252] Furthermore, this technology can also be configured as follows. (1) A communication device that performs wireless communication using multiple channels, A generation unit that generates multiple bit sequences with different content by applying encoding processing based on a predetermined error correction encoding scheme to the transmitted data sequence, A distribution unit that distributes the plurality of bit sequences to the plurality of channels, A communication device equipped with the following features. (2) The distribution unit distributes the plurality of bit sequences to the plurality of channels based on the channel state of each of the plurality of channels. The communication device according to (1) above. (3) The distribution unit distributes the plurality of bit sequences to a plurality of channels based on the delay amount until transmission for each of the plurality of channels. The communication device according to (1) above. (4) The distribution unit distributes the plurality of bit sequences to a plurality of channels based on the amount of resources available for transmission for each of the plurality of channels. The communication device according to (1) above. (5) The generation unit generates the plurality of bit sequences based on a plurality of source bit sequences generated by dividing the transmission data sequence and a plurality of parity bit sequences generated from the plurality of source bit sequences using the predetermined error correction coding method. The communication device according to any one of (1) to (4) above. (6) The communication device includes an acquisition unit that acquires predetermined information from another communication device that is the transmission partner of the bit sequence. The generation unit determines the number of parity bit sequences to be generated based on the predetermined information. The communication device according to (5) above. (7) A transmission unit that transmits the plurality of bit sequences using the plurality of channels to another communication device that starts decoding processing of the plurality of bit sequences even before receiving all the bit sequences of the plurality of bit sequences when a predetermined decoding start condition is satisfied; A reception unit that receives a response indicating whether or not reception of the bit sequence from the other communication device was successful. The transmission unit stops transmission of the plurality of bit sequences when it is determined based on the response that the other communication device satisfies the predetermined decoding start condition. The communication device according to any one of (1) to (6) above. (8) A transmitting unit that transmits the plurality of bit sequences using the plurality of channels to another communication device that starts decoding the plurality of bit sequences even before it has finished receiving all of the plurality of bit sequences, When the transmitting unit receives notification of the success of the decoding process from the other communication device, it stops transmitting the plurality of bit sequences. A communication device as described in any of (1) to (6) above. (9) The aforementioned predetermined error correction coding scheme is at least one of the following error correction coding schemes: vanishing correction coding, rateless coding, fountain coding, Tornado coding, LT (Luby Transform) coding, Raptor coding, LDPC (Low Density Parity Check) coding, BCH coding, RS (Reed Solomon) coding, and XOR (eXclusive OR) coding. A communication device as described in any of (1) to (8) above. (10) A communication device that performs wireless communication using multiple channels, An acquisition unit that acquires information regarding the decoding process of multiple bit sequences with different contents, which are generated by applying an encoding process based on a predetermined error correction encoding scheme to the transmitted data sequence, A receiving unit that receives at least one of the plurality of bit sequences that have been distributed and transmitted to the plurality of channels, A decoding unit that performs the decoding process on at least one of the received bit sequences into the transmitted data sequence, based on the information regarding the decoding process, A communication device equipped with the following features. (11) The system includes a start determination unit that determines whether or not to start the decoding process based on predetermined start criteria for the start of the decoding process, The decoding unit starts the decoding process when the predetermined start criteria are met. The communication device described in (10) above. (12) The system includes a decoding determination unit that determines whether the decoding process was successful or not, If the decoding process fails, the decoding unit will execute the decoding process using a larger bit sequence than the one used in the case of the decoding process failing. The communication device described in (11) above. (13) The start determination unit determines whether or not to start the decoding process based on the information regarding the decoding process. The communication device described in (11) or (12) above. (14) The start determination unit determines whether or not to start the decoding process based on whether the number of bit sequences received so far among the plurality of bit sequences has reached a predetermined number. A communication device as described in any of (11) to (13) above. (15) After it is determined that the decoding process has started, the system includes a notification unit that notifies other communication devices that transmitted the bit sequence of the success of the decoding process, regardless of whether the decoding process has been completed or not. A communication device as described in any of (11) to (14) above. (16) The notification unit, after determining that the transmitted data sequence that generated the plurality of bit sequences is data that satisfies a predetermined criterion, notifies the other communication device of the success of the decoding process, regardless of whether the decoding process has been completed or not. The communication device described in (15) above. (17) The aforementioned notification unit, If the transmitted data sequence is user data, after it is determined that the decoding process should be started, regardless of whether the decoding process has been completed or not, a notification of the success of the decoding process is sent to the other communication device. If the transmitted data sequence is control data, after the decoding process is successful, a notification of the success of the decoding process is sent to the other communication device. The communication device described in (16) above. (18) A wireless communication method using multiple channels, A generating unit that generates a plurality of bit sequences with different contents by applying an encoding process based on a predetermined error correction encoding method to a transmission data sequence; Distribute the plurality of bit sequences to the plurality of channels Communication method. (19) A communication method for wireless communication using a plurality of channels, comprising: Obtaining information regarding decoding processing of a plurality of bit sequences with different contents generated by applying an encoding process based on a predetermined error correction encoding method to a transmission data sequence; Receiving at least one of the plurality of bit sequences transmitted by being distributed to the plurality of channels; Performing the decoding process on at least one of the received plurality of bit sequences to the transmission data sequence based on the information regarding the decoding process; Communication method. (20) A communication system including a first communication device and a second communication device that each perform wireless communication using a plurality of channels, The first communication device includes: A generating unit that generates a plurality of bit sequences with different contents by applying an encoding process based on a predetermined error correction encoding method to a transmission data sequence; A distribution unit that distributes the plurality of bit sequences to the plurality of channels; The second communication device includes: An acquisition unit that acquires information regarding decoding processing of the plurality of bit sequences; A receiving unit that receives at least one of the plurality of bit sequences transmitted by being distributed to the plurality of channels;​​​​​​​​​​​​​​​ 30 relay stations 40 Terminal devices 11 Communications Department 21, 31, 41 Wireless Communication Section 12, 22, 32, 42 storage section 13, 23, 33, 43 Control Unit 211, 311, 411 Transmission Processing Unit 212, 312, 412 Receiving Processing Unit 213, 313, 413 antennas 231, 431 Receiving section 232, 432 Transmitting section 233, 433 Acquisition Department 234, 434 generation part 235, 435 distribution section 236, 436 Start determination section 237, 437 Decoding section 238, 438 Decoding and determination unit

Claims

1. A communication device that performs wireless communication using multiple channels, An acquisition unit that acquires information regarding the decoding process of multiple bit sequences with different contents, which are generated by applying an encoding process based on a predetermined error correction encoding scheme to the transmitted data sequence, A receiving unit that receives at least one of the plurality of bit sequences that have been distributed and transmitted to the plurality of channels, A start determination unit that determines whether or not to start the decoding process based on predetermined start criteria for the start of the decoding process, When the predetermined start criteria are met, a decoding unit performs the decoding process on at least one of the received bit sequences into the transmitted data sequence based on the information regarding the decoding process, If the transmitted data sequence is user data, after it is determined that the decoding process should be started, the notification unit notifies the other communication device that transmitted the bit sequence of the success of the decoding process, regardless of whether the decoding process has been completed or not. If the transmitted data sequence is control data, the notification unit notifies the other communication device of the success of the decoding process after the decoding process has been successful. A communication device equipped with the following features.

2. The system includes a decoding determination unit that determines whether the decoding process was successful or not, If the decoding process fails, the decoding unit will execute the decoding process using a larger bit sequence than the one used in the case of the decoding process failing. The communication device according to claim 1.

3. The start determination unit determines whether or not to start the decoding process based on the information regarding the decoding process. The communication device according to claim 1 or 2.

4. The start determination unit determines whether or not to start the decoding process based on whether the number of bit sequences received so far among the plurality of bit sequences has reached a predetermined number. A communication device according to any one of claims 1 to 3.

5. The aforementioned predetermined error correction coding scheme is at least one of the following error correction coding schemes: vanishing correction coding, rateless coding, fountain coding, Tornado coding, LT (Luby Transform) coding, Raptor coding, LDPC (Low Density Parity Check) coding, BCH coding, RS (Reed Solomon) coding, and XOR (eXclusive OR) coding. A communication device according to any one of claims 1 to 4.

6. A wireless communication method using multiple channels, An acquisition step to obtain information regarding the decoding process of multiple bit sequences with different content, which are generated by applying an encoding process based on a predetermined error correction encoding scheme to the transmitted data sequence, A receiving step of receiving at least one of the plurality of bit sequences that have been distributed and transmitted to the plurality of channels, A start determination step that determines whether or not to start the decoding process based on predetermined start criteria for the start of the decoding process, A decoding step in which, when the predetermined start criteria are met, the decoding process is performed on at least one of the received bit sequences into the transmitted data sequence based on the information regarding the decoding process, If the transmitted data sequence is user data, after it is determined that the decoding process should be started, regardless of whether the decoding process has been completed or not, a notification step is made to the communication device that transmitted the bit sequence to notify it of the success of the decoding process; if the transmitted data sequence is control data, after the decoding process is successful, a notification is made to the communication device to notify it of the success of the decoding process. Communication method.

7. A decoding determination step for determining whether the decoding process was successful or not, In the decoding step, if the decoding process is unsuccessful, the decoding process is performed using a larger bit sequence than in the case where the decoding process was unsuccessful. The communication method according to claim 6.

8. In the start determination step, a determination is made whether or not to start the decoding process based on the information relating to the decoding process. The communication method according to claim 6 or 7.

9. In the start determination step, a determination is made as to whether or not to start the decoding process based on whether or not the number of bit sequences received so far among the plurality of bit sequences has reached a predetermined number. The communication method according to any one of claims 6 to 8.

10. The predetermined error correction coding scheme is at least one error correction coding scheme from among the following: vanishing correction coding, rateless coding, fountain coding, Tornado coding, LT (Luby Transform) coding, Raptor coding, LDPC (Low Density Parity Check) coding, BCH coding, RS (Reed Solomon) coding, and XOR (eXclusive OR) coding. The communication method according to any one of claims 6 to 9.

11. A communication system comprising a first communication device and a second communication device, each performing wireless communication using multiple channels, The first communication device is A generation unit that generates multiple bit sequences with different content by applying encoding processing based on a predetermined error correction encoding scheme to the transmitted data sequence, The system includes a distribution unit that distributes the plurality of bit sequences to the plurality of channels, The second communication device is An acquisition unit that acquires information regarding the decoding process of the aforementioned plurality of bit sequences, A receiving unit that receives at least one of the plurality of bit sequences that have been distributed and transmitted to the plurality of channels, A start determination unit that determines whether or not to start the decoding process based on predetermined start criteria for the start of the decoding process, When the predetermined start criteria are met, a decoding unit performs the decoding process on at least one of the received bit sequences into the transmitted data sequence based on the information regarding the decoding process, If the transmitted data sequence is user data, after it is determined that the decoding process should be started, the notification unit notifies the first communication device that transmitted the bit sequence of the success of the decoding process, regardless of whether the decoding process has been completed or not, and if the transmitted data sequence is control data, the notification unit notifies the first communication device of the success of the decoding process after the decoding process has been successful. A communication system equipped with [the following features].

12. The distribution unit distributes the multiple bit sequences to the multiple channels based on the channel state of each of the multiple channels, the delay amount until transmission for each of the multiple channels, or the amount of resources available for transmission for each of the multiple channels. The communication system according to claim 11.

13. The generation unit generates the plurality of bit sequences based on a plurality of source bit sequences generated by dividing the transmission data sequence and a plurality of parity bit sequences generated from the plurality of source bit sequences using the predetermined error correction coding scheme. The communication system according to claim 11 or 12.

14. The first communication device is The system includes an acquisition unit that acquires predetermined information from the second communication device which is the recipient of the bit sequence, The generation unit determines the number of parity bit sequences to be generated based on the predetermined information. The communication system according to claim 13.

15. The first communication device is A transmitting unit that transmits the plurality of bit sequences to the second communication device using the plurality of channels, when a predetermined decoding start condition is met, the second communication device starts the decoding process of the plurality of bit sequences even before it has finished receiving all of the plurality of bit sequences. The system includes a response receiving unit that receives a response from the second communication device indicating whether or not the reception of the bit sequence was successful, If the transmitting unit determines, based on the response, that the second communication device has met the predetermined decoding start condition, it stops transmitting the plurality of bit sequences. A communication system according to any one of claims 11 to 14.

16. The first communication device is A transmitting unit that transmits the plurality of bit sequences using the plurality of channels to the second communication device, which starts decoding the plurality of bit sequences even before it has finished receiving all of the plurality of bit sequences, When the transmitting unit receives notification of the success of the decoding process from the second communication device, it stops transmitting the plurality of bit sequences. A communication system according to any one of claims 11 to 14.

17. The second communication device is The system includes a decoding determination unit that determines whether the decoding process was successful or not, If the decoding process fails, the decoding unit will execute the decoding process using a larger bit sequence than the one used in the case of the decoding process failing. A communication system according to any one of claims 11 to 16.

18. The start determination unit determines whether or not to start the decoding process based on the information relating to the decoding process. A communication system according to any one of claims 11 to 17.

19. The start determination unit determines whether or not to start the decoding process based on whether or not the number of bit sequences received so far among the plurality of bit sequences has reached a predetermined number. A communication system according to any one of claims 11 to 18.

20. The predetermined error correction coding scheme is at least one error correction coding scheme from among the following: vanishing correction coding, rateless coding, fountain coding, Tornado coding, LT (Luby Transform) coding, Raptor coding, LDPC (Low Density Parity Check) coding, BCH coding, RS (Reed Solomon) coding, and XOR (eXclusive OR) coding. A communication system according to any one of claims 11 to 19.

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