Terminals, wireless communication methods, base stations, and wireless communication systems

Abstract

A terminal, a wireless communication method, a base station, and a wireless communication system. The terminal has a control unit that controls a random access procedure in a cell, and a transmission unit that transmits a random access preamble using a first subcarrier spacing and an UL data channel using a second subcarrier spacing, the control unit deciding the first subcarrier spacing based on first information indicating the first subcarrier spacing and deciding the second subcarrier spacing based on second information indicating the second subcarrier spacing.

Description

[0001] This application is a divisional application of the patent application filed on July 14, 2017, with application number 201780043991.3, entitled "User Terminal and Wireless Communication Method". Technical Field

[0002] This invention relates to terminals, wireless communication methods, base stations, and wireless communication systems in next-generation mobile communication systems. Background Technology

[0003] In UMTS (Universal Mobile Telecommunications System) networks, Long Term Evolution (LTE) has been standardized with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). Furthermore, with the aim of further widening and increasing speed from LTE, successor systems to LTE (also known as, for example, LTE-A (LTE-Advanced), FRA (Future Radio Access), 4G, 5G, 5G+ (plus), NR (New RAT), LTE Rel.14, 15, etc.) have been studied.

[0004] In existing LTE systems (such as LTE Rel.8-13), UL data can be transmitted from the user terminal once UL synchronization has been established between the radio base station and the user terminal. Therefore, existing LTE systems support a random access procedure (also known as RACH: Random Access Channel Procedure) for establishing UL synchronization.

[0005] During random access, the user terminal obtains information related to the transmission timing of UL (Timing Advance) based on the response from the radio base station to the randomly selected preamble (random access preamble), and establishes UL synchronization based on the TA.

[0006] After establishing UL synchronization, the user terminal receives downlink control information (DCI) (UL license) from the wireless base station and then uses the UL resources allocated through the UL license to send UL data.

[0007] Existing technical documents

[0008] Non-patent literature

[0009] Non-patent document 1: 3GPP TS 36.300 "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2" Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] Future wireless communication systems (such as 5G and NR) will require a single framework to accommodate a wide variety of services, including high-speed and high-capacity communication (eMBB: enhanced Mobile Broadband), IoT (Internet of Things) devices, or MTC (Machine-Type Communication) devices, as well as massive connections from machine-to-machine (M2M) devices, and ultra-reliable and low-latency communication (URLLC).

[0012] In this way, future wireless communication systems are expected to coexist with multiple services having different latency reduction requirements. Therefore, future wireless communication systems are expected to accommodate multiple user terminals with different parameter sets (also known as multiple parameter sets, etc.). Here, a parameter set refers to at least one of the following: communication parameters in both the frequency direction and the time direction, or either one (e.g., subcarrier spacing, bandwidth, symbol length, CP (Cyclic Prefix) length, TTI length, number of symbols per TTI, radio frame structure, filtering processing, windowing processing, etc.).

[0013] In future wireless communication systems that accommodate multiple user terminals with different parameter sets, a problem arises in controlling the random access procedure. For example, the structure of the random access preamble sent by the user terminal has not yet been determined, and it is desirable to set it to be suitable for the parameter set being used.

[0014] The present invention was made in view of the aforementioned circumstances, and one of its objectives is to provide, in future wireless communication systems, user terminals and wireless communication methods capable of suitably implementing random access procedures (e.g., random access preamble transmission).

[0015] Methods for solving problems

[0016] One aspect of the present invention relates to a user terminal that communicates with a cell that uses an application-defined set of parameters, characterized in that it comprises: a control unit that controls the random access procedure in the cell; and a transmission unit that transmits a random access preamble with an application-defined subcarrier interval from a random access preamble supporting multiple subcarrier intervals.

[0017] Invention Effects

[0018] According to the present invention, random access procedures (e.g., random access preamble transmission) can be suitably implemented in future wireless communication systems. Attached Figure Description

[0019] Figure 1 This is a diagram illustrating an example of a contention-based random access procedure.

[0020] Figure 2 This is a diagram illustrating an example of a preamble format.

[0021] Figure 3A and Figure 3B This is a diagram illustrating an example of a random access preamble with different subcarrier spacing.

[0022] Figures 4A-4C This is a diagram illustrating an example of a random access preamble.

[0023] Figure 5 This is a diagram illustrating a complex use case of a random access preamble.

[0024] Figure 6 This is a schematic structural diagram of the wireless communication system involved in this embodiment.

[0025] Figure 7 This is a diagram illustrating an example of the overall structure of the wireless base station involved in this embodiment.

[0026] Figure 8 This diagram illustrates an example of the functional structure of the wireless base station involved in this embodiment.

[0027] Figure 9 This is a diagram illustrating an example of the overall structure of the user terminal involved in this embodiment.

[0028] Figure 10 This is a diagram illustrating an example of the functional structure of a user terminal involved in this embodiment.

[0029] Figure 11 This is a diagram illustrating an example of the hardware structure of the wireless base station and user terminal involved in this embodiment. Detailed Implementation

[0030] In existing LTE systems (such as LTE Rel.8-13), a random access procedure is supported for establishing UL synchronization. The random access procedure includes contention-based random access (also known as CBRA) and non-contention-based random access (also known as Non-CBRA, Contention-Free Random Access, etc.).

[0031] In Contention-Based Random Access (CBRA), the user terminal sends a randomly selected preamble from a plurality of preambles specified in each cell (random access preamble, random access channel (also known as PRACH), RACH preamble, etc.). Furthermore, contention-based random access is a user terminal-driven random access process that can be utilized, for example, during initial access, at the start or restart of UL transmission.

[0032] On the other hand, in Non-Content-Free Random Access (CFRA), the radio base station specifically allocates a preamble to the user terminal through the downlink (DL) control channel (PDCCH, Enhanced PDCCH, etc.), and the user terminal transmits the preamble allocated from the radio base station. Non-Content-Free Random Access is a network-driven random access process that can be utilized, for example, during handover, the start or restart of DL transmission (when DL transmission begins or restarts in the UL with retransmission indication information).

[0033] Figure 1 This is a diagram illustrating an example of contention-based random access. Figure 1In this process, the user terminal receives information in advance that indicates the structure of the random access channel (PRACH) (PRACH configuration, RACH configuration) through system information (such as MIB (Master Information Block) and / or SIB (System Information Block)) or higher-layer signaling (such as RRC (Radio Resource Control) signaling).

[0034] The PRACH structure information can represent, for example, multiple preambles specified in each cell (e.g., preamble format), time resources (e.g., system frame number, subframe number) and frequency resources (e.g., the offset of the starting position of the 6 resource blocks (PRB: Physical Resource Block) (prach-FrequencyOffset)) used in PRACH transmission.

[0035] like Figure 1 As shown, when the user terminal transitions from the idle (RRC_IDLE) state to the RRC connected (RRC_CONNECTED) state (e.g., during initial access), or when it is in the RRC connected state but has not established UL synchronization (e.g., at the start or restart of UL transmission), it randomly selects one of the multiple preambles shown in the PRACH structure information and sends the selected preamble (message 1) via PRACH.

[0036] If the wireless base station detects the preamble, it sends a Random Access Response (RAR) as its response (message 2). If the user terminal fails to receive the RAR within the specified period (RAR window) after sending the preamble, it increases the transmission power of the PRACH and retransmits (retransmits) the preamble. It should be noted that increasing the transmission power during retransmission is also known as power ramping.

[0037] Upon receiving the RAR, the user terminal adjusts the UL transmission timing based on the Timing Advancement (TA) contained in the RAR to establish UL synchronization. Furthermore, the user terminal sends a higher-layer (L2 / L3) control message (Message 3) using the UL resources specified by the UL license contained in the RAR. This control message contains the user terminal's identifier (UE-ID). This identifier can be, for example, a C-RNTI (Cell-RadioNetwork Temporary Identifier) ​​if in an RRC connected state, or an S-TMSI (System Architecture Evolution-Temporary Mobile Subscriber Identifier) ​​or other higher-layer UE-IDs if in an idle state.

[0038] The wireless base station sends a contention resolution message (message 4) based on the control messages from higher layers. This contention resolution message is sent based on the destination identifier of the user terminal contained in the aforementioned control messages. If the contention resolution message is successfully detected, the user terminal sends an acknowledgment (ACK) in the HARQ (Hybrid Automatic Repeat reQuest) to the wireless base station. Thus, the idle user terminal transitions to the RRC connected state.

[0039] On the other hand, if the user terminal fails to detect the contention resolution message, it determines that a contention has occurred, reselects the preamble, and repeats the random access procedure of messages 1 to 4. If the wireless base station detects that the contention has been resolved through an ACK from the user terminal, it sends a UL license to the user terminal. The user terminal then uses the UL resources allocated through the UL license to begin UL data processing.

[0040] In the contention-based random access described above, the user terminal can autonomously initiate the random access process when it desires to send UL data. Furthermore, after establishing UL synchronization, UL data is sent using UL resources specifically allocated to the user terminal through UL licensing, thus enabling highly reliable UL transmission.

[0041] In the aforementioned random access process, the random access preamble (PRACH) sent by the user terminal consists of a cyclic prefix (CP) interval, a preamble interval, and a guard time (GT) interval. Furthermore, the user terminal specifies four preamble formats that can be used in the transmission of the random access preamble.

[0042] like Figure 2 As shown, preamble format 0 has a TTI length of 1 ms, a CP interval of 102.6 μs, a preamble interval of 800 μs, and a GT interval of 97.4 μs, with a maximum coverage of 15 km. Preamble format 1 has a TTI length of 2 ms or 3 ms, a CP interval of 684 μs, a preamble interval of 800 μs, and a GT interval of 516 μs, with a maximum coverage of 77 km when the TTI length is 2 ms, and a maximum coverage of 100 km when the TTI length is 3 ms. Preamble format 2 has a TTI length of 2 ms, a CP interval of 202.6 μs, a preamble interval of 2 × 800 μs, and a GT interval of 197.4 μs, with a maximum coverage of 30 km. Preamble format 3 has a TTI length of 3 [ms], a CP interval of 684 [μs], a preamble interval of 2 × 800 [μs] and a GT interval of 716 [μs], and a maximum coverage of 100 [km].

[0043] In addition, in existing LTE systems, the subcarrier spacing (SC spacing) of the random access preamble is defined as 1.25 kHz in preamble formats 0-3.

[0044] However, in future wireless communication systems' radio access methods (5G RAT), to support a wide range of frequency bands or diverse services with varying requirements, it is anticipated that multiple parameter sets (also known as multi-parameter sets) will be incorporated. Here, a parameter set (numerology) refers to the set of communication parameters (wireless parameters) in both the frequency and time directions, or either one. This set of communication parameters may include, for example, at least one of the following: subcarrier spacing, bandwidth, symbol length, CP length, TTI length, number of symbols per TTI, radio frame structure, filtering processing, windowing processing, etc.

[0045] "Different parameter sets" means that at least one of the following parameters differs between parameter sets: subcarrier spacing, bandwidth, symbol length, CP length, TTI length, number of symbols per TTI, radio frame structure, etc., but is not limited to these.

[0046] In future wireless communication systems that support multiple parameter sets, it is envisioned that different parameter sets will be applied on the same carrier or different carriers for communication. In this case, the problem arises in how to control the aforementioned random access procedure in such future wireless communication systems. For example, the structure of the random access preamble sent by the user terminal has not yet been determined; it is desirable to set a structure suitable for the parameter set being used.

[0047] Figure 3A , Figure 3B This is a diagram illustrating an example of a random access preamble with different subcarrier spacing. Figure 3A The random access preamble shown (e.g., with 839 sequences) has a bandwidth of 1.04 MHz. This is equivalent to 839 subcarriers spaced 1.25 kHz apart. Furthermore, the preamble length is 800 μs.

[0048] on the other hand, Figure 3B The bandwidth of the random access preamble shown is 4.195 MHz. This is equivalent to 839 subcarriers spaced 5 kHz apart. Furthermore, the preamble length is 200 μs. Figure 3B The bandwidth (subcarrier spacing) of the random access preamble shown is Figure 3A The bandwidth (subcarrier spacing) of the random access preamble shown is approximately four times that of the previous one. Furthermore, Figure 3B The length of the preamble shown in the random access preamble is . Figure 3A The preamble length shown is 1 / 4 of the random access preamble length. In this way, the subcarrier spacing and the preamble length are reciprocals of each other. It should be noted that the bandwidth, subcarrier spacing, and preamble length for the random access preamble are not limited to... Figure 3A , Figure 3B The example shown can be configured appropriately.

[0049] Bandwidth affects timing accuracy (timing offset estimation accuracy). Furthermore, subcarrier spacing and bandwidth affect capacity or contention probability. For example, a wider subcarrier spacing can effectively prevent inter-channel interference caused by Doppler shift due to user terminal movement, or transmission quality degradation caused by phase noise in the user terminal's receiver. In particular, in high-frequency bands such as tens of GHz, widening the subcarrier spacing can effectively prevent transmission quality degradation.

[0050] Therefore, the subcarrier spacing is wide Figure 3B The parameter set shown is suitable for high-frequency band communication. Furthermore, by widening the subcarrier spacing, the tolerance to high-speed movement is also enhanced; therefore, a wider subcarrier spacing... Figure 3B The parameter set shown is suitable for high-speed movement.

[0051] Preamble length affects SNR (Signal Noise Ratio) and cell radius. For example, at lower carrier frequencies (e.g., below 6 GHz), coverage is prioritized, using the same narrow subcarrier spacing as existing LTE. Figure 3A The parameter set shown is suitable.

[0052] On the other hand, at high carrier frequencies (6GHz–100GHz), considering the ability to apply wide bandwidth and tolerance to phase noise, it is advisable to increase the subcarrier spacing and the TTI length. Similarly, in the preamble, increasing the subcarrier spacing while keeping the preamble length short can be considered... Figure 3B The parameter set shown is suitable. This parameter set is also suitable for massive MIMO (Massive Multiple-Input and Multiple-Output) utilizing a large number of antenna elements. Furthermore, in URLLC (Ultra-reliable and low-latency communication), where data volume is small but latency reduction is required, it can be considered suitable for services with stringent latency requirements. Additionally, as another example, in high-speed mobile environments requiring high tolerance to Doppler frequencies, a parameter set with a short TTI length is suitable.

[0053] In addition, according to Figure 3A The parameter set shown allows for an increased CP length even when the ratio of the CP length to the total preamble length remains constant, due to the overall increase in preamble length. This enables stronger (robust) wireless communication to handle multipath fading in the communication path.

[0054] Furthermore, the parameter set used by the user terminal can be semi-statically set through higher-layer signaling such as RRC (Radio Resource Control) signaling or broadcast information, or dynamically changed through physical layer control information (L1 / L2 control channels). Alternatively, it can be changed through a combination of higher-layer signaling and physical layer control information. In addition to the parameter set, multiple preamble sequences or sequence lengths can also be defined to configure the UE.

[0055] In this way, the inventors, taking into account the different structures (parameter sets) suitable for random access preambles in communication environments (e.g., carrier frequency, service type, mobile speed, etc.), conceived of defining a random access preamble that supports multiple subcarrier intervals that can differ from the parameter sets of other physical channels. For example, a random access preamble supporting multiple subcarrier intervals is defined, and a user terminal transmits a random access preamble having one of these subcarrier intervals.

[0056] That is, in one aspect of the present invention, the user terminal is a user terminal that communicates with a cell that uses a set of parameters specified by the application, controls the random access process in the cell, and sends a random access preamble with a specified subcarrier interval from a random access preamble that supports multiple subcarrier intervals.

[0057] In this way, by predefining a random access preamble that supports multiple subcarrier intervals, random access procedures (e.g., random access preamble transmission) can be appropriately implemented in future wireless communication systems.

[0058] Here, the random access preamble (PRACH) transmitted by the user terminal consists of a cyclic prefix (CP) interval, a preamble interval, and a guard time (GT) interval. Furthermore, the configuration of the random access preamble is determined at least by the subcarrier spacing and the number of repetitions of the preamble symbols. That is, in one of the above methods, the random access preamble with a specified subcarrier spacing can also be repeatedly transmitted. This improves the signal-to-noise ratio (SNR).

[0059] It should be noted that a preamble format is specified for the random access preamble corresponding to the parameter set. This preamble format for the random access preamble corresponding to the parameter set is also included in this invention.

[0060] Hereinafter, a detailed description of one embodiment of the present invention will be provided with reference to the accompanying drawings. It should be noted that the random access procedure involved in this embodiment can also be applied to contention-based random access and non-contention-based random access.

[0061] (First method)

[0062] In the first method, when setting a random access preamble that supports multiple subcarrier intervals, multiple subcarrier intervals that are multiples of a predetermined value (e.g., 1.25 kHz) are used. In the first method, the subcarrier interval of the random access preamble can be set independently of the subcarrier interval applied to the UL data channel. Therefore, appropriate time error estimation can be performed.

[0063] In the first approach, similar to the LTE system, multiple subcarrier intervals can be set based on a 1.25kHz subcarrier interval. Examples include 1.25kHz, 2.5kHz, 5kHz, 10kHz, 20kHz, 40kHz, etc. By setting the multiples to powers of 2 in this way, the expansion of the LTE system becomes easier. Furthermore, the user terminal can also select the same subcarrier interval as the random access preamble of the LTE system, depending on the required conditions.

[0064] (Second method)

[0065] In the second approach, when setting a random access preamble that supports multiple subcarrier intervals, multiple subcarrier intervals (e.g., 15 kHz) that are different from the random access preambles of existing LTE systems are used.

[0066] In the second method, similar to the data channel, multiple subcarrier intervals can be set based on a 15kHz subcarrier interval. For example, 3.75kHz, 15kHz, 30kHz, 60kHz, 120kHz, etc. By setting the same subcarrier interval as other physical channels in this way, the guard band can be omitted between different channels.

[0067] In both methods 1 and 2, a random access preamble supporting multiple subcarrier intervals can be pre-set, and the random access preamble associated with the subcarrier interval can be selected based on specified conditions. These specified conditions can include the type of parameter set, SNR, and mobile speed. In this way, by selecting a random access preamble for a specific subcarrier interval from those supporting multiple subcarrier intervals based on specified conditions, an appropriate random access preamble can be transmitted according to the required conditions. As a result, a suitable random access procedure can be performed.

[0068] Furthermore, in both methods 1 and 2, the random access preamble can also be configured with a predefined bandwidth (one or more). This allows the user terminal to send an appropriate random access preamble based on requirements such as time error estimation.

[0069] Furthermore, in methods 1 and 2, as described above, the random access preamble is set at least by the subcarrier interval and the number of repetitions of the preamble symbols. For example, as Figure 4A As shown, a random access preamble can be constructed using a bandwidth of approximately 1 MHz with 67 subcarriers spaced 15 kHz apart. Furthermore, in this case, it is preferable to repeatedly transmit the random access preamble.

[0070] In this case, in a random access preamble consisting of repeated symbols with a preamble length of 66 μs, analog beamforming (a beamforming method that performs beamforming after RF transformation) can also be applied, scanning the beam orientation (beam scanning) for each symbol. This can improve the SNR.

[0071] On the other hand, such as Figure 4B As shown, a random access preamble can be constructed using a bandwidth of approximately 1 MHz with 277 subcarriers spaced 3.75 kHz apart. In this case, the random access preamble constructed by repeating symbols of a preamble length of 267 μs is not suitable for analog beamforming; therefore, symbol synthesis is preferred to improve the SNR. It should be noted that the random access preamble is not limited to... Figure 4A , Figure 4B The example shown can be configured appropriately.

[0072] Furthermore, in the case of the orientation of the scanning beam, such as Figure 4C As shown, CP and GT can also be added to each preamble, and transmission can be performed using only the preamble associated with the optimal beam. Here, the optimal beam can be pre-measured using downlink synchronization signals (SS) or beam detection reference signals (BRS), etc. Figure 4C In the structure, with such Figure 4A Compared to repeatedly sending preambles, it can stop sending unnecessary preambles.

[0073] In one embodiment of the present invention, such as Figure 5 As shown, multiple random access preambles with different subcarrier spacings can be time-multiplexed or frequency-multiplexed. For example, Figure 5 The diagram illustrates the multiplexing of a random access preamble A with a bandwidth of approximately 1 MHz, a subcarrier spacing of 15 kHz, a symbol length of 66.7 μs, and a repetition count of 4; a random access preamble B with a bandwidth of approximately 1 MHz, a subcarrier spacing of 3.75 kHz, a symbol length of 267 μs, and no repetitions; and a random access preamble C with a bandwidth of approximately 2 MHz, a subcarrier spacing of 15 kHz, a symbol length of 66.7 μs, and a repetition count of 4.

[0074] Figure 5 In this approach, random access preamble A and random access preamble B are time-multiplexed in advance, and random access preambles A, B, and C are time- and frequency-multiplexed. By time-multiplexing and / or frequency-multiplexing multiple random access preambles, contention can be suppressed between user terminals transmitting random access preambles with different structures. It should be noted that the multiplexing of random access preambles is not limited to... Figure 5 The example shown can be configured appropriately.

[0075] (Wireless Communication System)

[0076] The structure of the wireless communication system according to this embodiment will now be described. This wireless communication system applies the wireless communication methods described in the above-described embodiments. It should be noted that the wireless communication methods described in the above-described embodiments can be applied individually or in combination.

[0077] Figure 6 This diagram illustrates an example of the schematic structure of the wireless communication system according to this embodiment. In wireless communication system 1, carrier aggregation (CA) and / or dual connectivity (DC), which integrates multiple basic frequency blocks (component carriers) using the system bandwidth of an LTE system (e.g., 20MHz) as a unit, can be applied. It should be noted that wireless communication system 1 can also be referred to as SUPER 3G, LTE-A (LTE-Advanced), IMT-Advanced, 4G, 5G, FRA (Future Radio Access), NR (New Radio), etc.

[0078] Figure 6 The wireless communication system 1 shown includes: a wireless base station 11 forming a macro cell C1, and wireless base stations 12a to 12c configured within the macro cell C1 and forming smaller cells C2 that are narrower than the macro cell C1. Furthermore, user terminals 20 are configured in both the macro cell C1 and each smaller cell C2. Alternatively, the system can be configured to apply different parameter sets between cells. It should be noted that a parameter set refers to a set of communication parameters for the design of signals in a certain RAT, or for additional features added to the design of the RAT.

[0079] User terminal 20 can connect to both wireless base station 11 and wireless base station 12. User terminal 20 is intended to simultaneously utilize macro cell C1 and small cell C2 using different frequencies via CA or DC. Furthermore, user terminal 20 can utilize multiple cells (CCs) (e.g., two or more CCs) to apply CA or DC. Additionally, user terminal can utilize licensed band CCs and unlicensed band CCs as multiple cells. It should be noted that the configuration can include a TDD carrier with a shortened TTI applied to any of the multiple cells.

[0080] User terminal 20 and wireless base station 11 can communicate using a narrow-bandwidth carrier (also known as a legacy carrier) in a relatively low frequency band (e.g., 2 GHz). Conversely, user terminal 20 and wireless base station 12 can communicate using a wide-bandwidth carrier in a relatively high frequency band (e.g., 3.5 GHz, 5 GHz, 30–70 GHz), or they can use the same carrier as wireless base station 11. It should be noted that the frequency band structure used by each wireless base station is not limited to this.

[0081] The wireless base station 11 and the wireless base station 12 (or the two wireless base stations 12) can be connected by a wired connection (e.g., fiber optic cable according to CPRI (Common Public Radio Interface), X2 interface, etc.) or a wireless connection.

[0082] Wireless base station 11 and each wireless base station 12 are respectively connected to the host station device 30, and connected to the core network 40 via the host station device 30. It should be noted that the host station device 30 includes, but is not limited to, access gateway devices, radio network controllers (RNCs), mobility management entities (MMEs), etc. In addition, each wireless base station 12 can also be connected to the host station device 30 via wireless base station 11.

[0083] It should be noted that wireless base station 11 is a wireless base station with relatively wide coverage, and can also be referred to as a micro base station, aggregation node, eNB (eNodeB), transmit / receive point, etc. Furthermore, wireless base station 12 is a wireless base station with local coverage, and can also be referred to as a small base station, micro base station, pico base station, femtocell, HeNB (Home eNodeB), RRH (Remote Radio Head), transmit / receive point, etc. Hereinafter, without distinguishing between wireless base stations 11 and 12, they will be collectively referred to as wireless base station 10.

[0084] Each user terminal 20 is a terminal that supports various communication methods such as LTE and LTE-A, and may include not only mobile communication terminals but also fixed communication terminals.

[0085] In wireless communication system 1, as a wireless access method, OFDMA (Orthogonal Frequency Division Multiple Access) can be applied to the downlink (DL), and SC-FDMA (Single Carrier Frequency Division Multiple Access) can be applied to the uplink (UL). OFDMA is a multi-carrier transmission method that divides the frequency band into multiple narrow frequency bands (subcarriers) and maps data to each subcarrier for communication. SC-FDMA is a single-carrier transmission method that divides the system bandwidth into bands formed by one or more consecutive resource blocks for each terminal and reduces inter-terminal interference by allowing multiple terminals to utilize different bands. It should be noted that the uplink and downlink wireless access methods are not limited to combinations of these; OFDMA can also be used in the UL.

[0086] In the wireless communication system 1, the DL channel utilizes the DL data channel (also known as PDSCH: Physical Downlink Shared Channel, DL Shared Channel, etc.), broadcast channel (PBCH: Physical Broadcast Channel), L1 / L2 control channel, etc., shared among all user terminals 20. User data or higher-layer control information, SIBs (System Information Blocks), etc., are transmitted via the PDSCH. Furthermore, the MIB (Master Information Block) is transmitted via the PBCH.

[0087] L1 / L2 control channels include DL control channels (PDCCH (Physical Downlink Control Channel), EPDCCH (Enhanced Physical Downlink Control Channel)), PCFICH (Physical Control Format Indicator Channel), and PHICH (Physical Hybrid-ARQ Indicator Channel). PDCCH transmits downlink control information (DCI) containing scheduling information for PDSCH and PUSCH. PCFICH transmits the number of OFDM symbols used in PDCCH. EPDCCH and PDSCH are frequency-division multiplexed and used for DCI transmission in the same way as PDCCH. At least one of PHICH, PDCCH, and EPDCCH can transmit HARQ retransmission indication information (ACK / NACK) for PUSCH.

[0088] In the wireless communication system 1, the UL channel utilizes the UL data channel (also known as PUSCH: Physical Uplink Shared Channel, UL Shared Channel, etc.), UL control channel (PUCCH: Physical Uplink Control Channel), and random access channel (PRACH: Physical Random Access Channel) shared by each user terminal 20. User data and higher-layer control information are transmitted via the PUSCH. Uplink control information (UCI: Uplink Control Information), including at least one of retransmission indication information (ACK / NACK) or channel state information (CSI), is transmitted via the PUSCH or PUCCH. The random access preamble used for establishing a connection with the cell can be transmitted via the PRACH.

[0089] <Wireless Base Station>

[0090] Figure 7This diagram illustrates an example of the overall structure of the wireless base station according to this embodiment. A predetermined set of parameters is applied in this wireless base station. The wireless base station 10 includes: multiple transmit / receive antennas 101, an amplifier unit 102, a transmit / receive unit 103, a baseband signal processing unit 104, a call processing unit 105, and a transmission path interface 106. It should be noted that the transmit / receive antennas 101, the amplifier unit 102, and the transmit / receive unit 103 can each be configured to include one or more.

[0091] The DL data sent from the wireless base station 10 to the user terminal 20 is input to the baseband signal processing unit 104 from the host device 30 via the transmission path interface 106.

[0092] In the baseband signal processing unit 104, regarding DL data, it performs PDCP (Packet Data Convergence Protocol) layer processing, user data segmentation / combination, RLC (Radio Link Control) retransmission control and other RLC layer transmission processing, MAC (Medium Access Control) retransmission control (e.g., HARQ transmission processing), scheduling, transmission format selection, channel coding, Inverse Fast Fourier Transform (IFFT) processing, precoding processing, and other transmission processing, and then forwards it to the transmit / receive unit 103. Furthermore, regarding DL control signals, it also performs channel coding or Inverse Fast Fourier Transform transmission processing, and then forwards it to the transmit / receive unit 103.

[0093] The transmitting / receiving unit 103 converts the baseband signal output from the baseband signal processing unit 104 after precoding each antenna into a wireless frequency band and transmits it. The wireless frequency signal, which has undergone frequency conversion by the transmitting / receiving unit 103, is amplified by the amplifier unit 102 and transmitted from the transmitting / receiving antenna 101. The transmitting / receiving unit 103 can be composed of a transmitter / receiver, a transmitting / receiving circuit, or a transmitting / receiving device, as described based on common knowledge in the art to which this invention pertains. It should be noted that the transmitting / receiving unit 103 can also be configured as an integrated transmitting / receiving unit, or it can be composed of a transmitting unit and a receiving unit.

[0094] On the other hand, for the UL signal, the radio frequency signal received by the transmit / receive antenna 101 is amplified by the amplifier unit 102. The transmit / receive unit 103 receives the UL signal amplified by the amplifier unit 102. The transmit / receive unit 103 converts the received signal frequency into a baseband signal and outputs it to the baseband signal processing unit 104.

[0095] In the baseband signal processing unit 104, the user data contained in the input UL signal undergoes Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing, error correction decoding, MAC retransmission control reception processing, and RLC and PDCP layer reception processing, and is forwarded to the host device 30 via the transmission path interface 106. The call processing unit 105 performs call processing such as setting or releasing communication channels, or status management of the wireless base station 10, or management of wireless resources.

[0096] The transmission path interface 106 transmits and receives signals with the host station device 30 via a designated interface. In addition, the transmission path interface 106 can also transmit and receive signals (backhaul signaling) with other wireless base stations 10 via an inter-base station interface (e.g., fiber optic or X2 interface according to CPRI (Common Public Radio Interface)).

[0097] It should be noted that the transmitting / receiving unit 103 may further include a simulated beamforming unit that implements simulated beamforming. The simulated beamforming unit can be constructed from simulated beamforming circuits (e.g., phase shifters, phase-shifting circuits) or simulated beamforming devices (e.g., phase shifters) described based on common knowledge in the art to which this invention pertains. Furthermore, the transmitting / receiving antenna 101 can be constructed from, for example, an array antenna.

[0098] It should be noted that the transmitting and receiving unit 103 transmits DL signals (such as DL control signals (DL control channel), DL data signals (DL data channel, DL shared channel), DL reference signals (DM-RS, CSI-RS, etc.), discovery signals, synchronization signals, broadcast signals, etc.) and receives UL signals (such as UL control signals (UL control channel), UL data signals (UL data channel, UL shared channel), UL reference signals, etc.).

[0099] Specifically, in one embodiment of the present invention, the transmitting and receiving unit 103 transmits information related to the parameter set used by the user terminal. For example, the transmitting and receiving unit 103 transmits information about the random access preamble used by the user terminal. Examples of such random access preamble information include, for instance, bit information for determining the preamble format, information for indicating the subcarrier spacing, and information for indicating the repetition count.

[0100] Furthermore, during random access, the transmitting / receiving unit 103 sends messages 2, 4, and UL authorization to the user terminal 20. Additionally, during random access, the transmitting / receiving unit 103 receives random access preamble, message 3, and ACK from the user terminal 20. In this case, the random access preamble information can be semi-statically set via higher-layer signaling such as RRC (Radio Resource Control) signaling or broadcast information, or dynamically changed via physical layer control information (L1 / L2 control channels). Alternatively, it can be changed via a combination of higher-layer signaling and physical layer control information.

[0101] Furthermore, the transmitting / receiving unit 103 transmits configuration information for multiple contention-type resource regions with different parameters via at least one of system information, higher-layer signaling, and DL control channel. This configuration information may also include, for each contention-type resource region, at least one of the following: the number of time resources, the number of frequency resources, parameters related to repetition count, parameters related to transmission processing, parameters related to frequency hopping, resource group identification information, parameters related to time and / or frequency location, parameter set, and parameters related to retransmission control.

[0102] The transmitting unit and receiving unit of the present invention are composed of a transmitting / receiving unit 103 and / or a transmission path interface 106.

[0103] Figure 8 This diagram illustrates an example of the functional structure of the wireless base station according to this embodiment. It should be noted that... Figure 8 The diagram primarily shows the functional blocks of the characteristic parts in this embodiment. The wireless base station 10 also has other functional blocks necessary for wireless communication. For example... Figure 8 As shown, the baseband signal processing unit 104 includes at least: a control unit 301, a transmit signal generation unit 302, a mapping unit 303, a receive signal processing unit 304, and a measurement unit 305.

[0104] The control unit 301 performs overall control of the wireless base station 10. The control unit 301 can be composed of a controller, control circuit, or control device described based on common knowledge in the technical field to which this invention pertains.

[0105] Control unit 301 controls, for example, the generation of signals based on signal generation unit 302, or the distribution of signals based on mapping unit 303. Furthermore, control unit 301 controls the reception and processing of signals based on signal processing unit 304, or the measurement of signals based on measurement unit 305.

[0106] Control unit 301 controls the scheduling (e.g., resource allocation) of DL signals and / or UL signals. Specifically, control unit 301 controls transmission signal generation unit 302, mapping unit 303, and transmission / reception unit 103 to generate and transmit DCI (DL allocation) containing scheduling information for DL ​​data channels and DCI (UL license) containing scheduling information for UL data channels.

[0107] Control unit 301 controls the random access process. That is, control unit 301 controls... Figure 1 The random access procedure shown.

[0108] The transmitting signal generation unit 302 generates DL signals (DL control channel, DL data channel, DL reference signal such as DM-RS, etc.) based on instructions from the control unit 301, and outputs them to the mapping unit 303. The transmitting signal generation unit 302 can be composed of a signal generator, signal generation circuit or signal generation device that is commonly known in the art to which this invention pertains.

[0109] Based on instructions from the control unit 301, the mapping unit 303 maps the DL signal generated in the transmission signal generation unit 302 to a specified radio resource and outputs it to the transmission and reception unit 103. The mapping unit 303 can be composed of a mapper, mapping circuit, or mapping device described based on common knowledge in the art to which this invention pertains.

[0110] The receiving signal processing unit 304 performs receiving processing (e.g., demapping, demodulation, decoding, etc.) on the received signal input from the transmitting and receiving unit 103. Here, the received signal is, for example, a UL signal (UL control channel, UL data channel, UL reference signal, etc.) transmitted from the user terminal 20. The receiving signal processing unit 304 can be composed of a signal processor, signal processing circuit, or signal processing device described based on common knowledge in the art to which this invention pertains.

[0111] The receiving signal processing unit 304 outputs the decoded information to the control unit 301. For example, the receiving signal processing unit 304 outputs at least one of control information and UL data to the control unit 301. In addition, the receiving signal processing unit 304 outputs the received signal or the received and processed signal to the measurement unit 305.

[0112] The measurement unit 305 performs measurements related to the received signal. The measurement unit 305 can be composed of a measuring instrument, measuring circuit, or measuring device described based on common knowledge in the art to which this invention pertains.

[0113] The measurement unit 305 can also measure, for example, the received power of the received signal (e.g., RSRP (Reference Signal Received Power)), the received quality (e.g., RSRQ (Reference Signal Received Quality)), or the channel state. The measurement results can also be output to the control unit 301.

[0114] <User Terminal>

[0115] Figure 9 This diagram illustrates an example of the overall structure of the user terminal according to this embodiment. The user terminal 20 includes: multiple transmit / receive antennas 201, an amplifier unit 202, a transmit / receive unit 203, a baseband signal processing unit 204, and an application unit 205. It should be noted that the transmit / receive antennas 201, the amplifier unit 202, and the transmit / receive unit 203 can each be configured to include one or more.

[0116] The radio frequency signal received through the transmit / receive antenna 201 is amplified by the amplifier unit 202. The transmit / receive unit 203 receives the DL signal amplified by the amplifier unit 202. The transmit / receive unit 203 converts the received signal frequency into a baseband signal and outputs it to the baseband signal processing unit 204. The transmit / receive unit 203 can be constructed from a transmitter / receiver, transmit / receive circuit, or transmit / receive device as described based on common knowledge in the art to which this invention pertains. It should be noted that the transmit / receive unit 203 can also be constructed as an integrated transmit / receive unit, or it can be composed of a transmit unit and a receive unit.

[0117] The baseband signal processing unit 204 performs FFT processing, error correction decoding, and retransmission control on the input baseband signal. The DL data is forwarded to the application unit 205. The application unit 205 performs processing related to layers higher than the physical or MAC layers. Furthermore, system information or higher-level control information within the DL data is also forwarded to the application unit 205.

[0118] On the other hand, UL data is input from application unit 205 to baseband signal processing unit 204. Baseband signal processing unit 204 performs retransmission control (e.g., HARQ transmission processing), or channel coding, precoding, Discrete Fourier Transform (DFT) processing, IFFT processing, etc., and forwards it to transmit / receive unit 203. Transmit / receive unit 203 converts the baseband signal output from baseband signal processing unit 204 into a radio frequency band and transmits it. The radio frequency signal, after frequency conversion by transmit / receive unit 203, is amplified by amplifier unit 202 and transmitted from transmit / receive antenna 201.

[0119] It should be noted that the transmitting / receiving unit 203 may further include a simulated beamforming unit that implements simulated beamforming. The simulated beamforming unit can be constructed from simulated beamforming circuits (e.g., phase shifters, phase-shifting circuits) or simulated beamforming devices (e.g., phase shifters) described based on common knowledge in the art to which this invention pertains. Furthermore, the transmitting / receiving antenna 201 can be constructed from, for example, an array antenna.

[0120] The transmitting / receiving unit 203 receives DL signals (e.g., DL control signals (DL control channel), DL data signals (DL data channel, DL shared channel), DL reference signals (DM-RS, CSI-RS, etc.), discovery signals, synchronization signals, broadcast signals, etc.), and transmits UL signals (e.g., UL control signals (UL control channel), UL data signals (UL data channel, UL shared channel), UL reference signals, etc.). Furthermore, the transmitting / receiving unit 203 transmits a random access preamble with a specified subcarrier interval from a random access preamble supporting multiple subcarrier intervals.

[0121] Specifically, in one embodiment of the present invention, the transmitting and receiving unit 203 receives information related to the parameter set used by the user terminal. For example, the transmitting and receiving unit 203 receives information about the random access preamble used by the user terminal. Examples of this random access preamble information include, for instance, bit information for determining the preamble format, information for indicating the subcarrier spacing, and information for indicating the repetition count. Furthermore, during random access, the transmitting and receiving unit 203 receives messages 2, 4, UL permission, etc., from the user terminal 20. Additionally, during random access, the transmitting and receiving unit 203 sends the random access preamble, message 3, ACK, etc., to the user terminal 20. In this case, the transmitting and receiving unit 203 may also repeatedly transmit the random access preamble.

[0122] Furthermore, the transmitting / receiving unit 203 receives configuration information for multiple contention-type resource regions with different parameters through at least one of system information, higher-layer signaling, and DL control channels. This configuration information may also include, for each contention-type resource region, at least one of the following: the number of time resources, the number of frequency resources, parameters related to repetition count, parameters related to transmission processing, parameters related to frequency hopping, parameters related to preamble, resource group identification information, parameters related to time and / or frequency location, parameter sets, and parameters related to retransmission control.

[0123] Transmitter / receiver unit 203 Figure 4A As shown, in the case of analog beamforming where the beam directivity is changed per symbol when applying random access preamble, beamforming is performed after RF processing of the signal.

[0124] Figure 10 This diagram illustrates an example of the functional structure of the user terminal involved in this embodiment. It should be noted that... Figure 10 The diagram mainly shows the functional blocks of the characteristic parts in this embodiment. The user terminal 20 also has other functional blocks necessary for wireless communication. For example... Figure 10 As shown, the baseband signal processing unit 204 of the user terminal 20 includes at least a control unit 401, a transmit signal generation unit 402, a mapping unit 403, a receive signal processing unit 404, and a measurement unit 405.

[0125] The control unit 401 performs overall control of the user terminal 20. The control unit 401 can be composed of a controller, control circuit, or control device described based on common knowledge in the technical field to which this invention pertains.

[0126] Control unit 401 controls, for example, the generation of signals based on transmission signal generation unit 402, or the distribution of signals based on mapping unit 403. Furthermore, control unit 401 controls the reception and processing of signals based on reception signal processing unit 404, or the measurement of signals based on measurement unit 405.

[0127] The control unit 401 acquires the DL control channel and DL data channel transmitted from the wireless base station 10 from the receiving signal processing unit 404. Specifically, the control unit 401 controls the transmitting and receiving unit 203 and the receiving signal processing unit 404 to perform blind decoding of the DL control channel to detect the DCI, and to receive the DL data channel based on the DCI. Furthermore, the control unit 401 estimates the channel gain based on the DL reference signal, and demodulates the DL data channel based on the estimated channel gain.

[0128] The control unit 401 can also control the transmission of retransmission control information (e.g., HARQ-ACK) sent via the UL control channel or UL data channel based on the result of determining whether retransmission control for the DL data channel is required. Furthermore, the control unit 401 can also control the transmission of channel state information (CSI) generated based on the DL reference signal.

[0129] In one embodiment of the present invention, control unit 401 selects a random access preamble for a specified subcarrier interval from random access preambles supporting multiple subcarrier intervals. In this case, control unit 401 selects the random access preamble for the specified subcarrier interval based on specified conditions such as the type of parameter set, SNR, and moving speed. Specifically, control unit 401 as follows: Figure 3A and Figure 3B As shown, a random access preamble with a specified subcarrier spacing is selected. Furthermore, the control unit 401 sets a predefined bandwidth for the random access preamble.

[0130] The signal generation unit 402 generates UL signals (UL control channel, UL data channel, UL reference signal, etc.) based on instructions from the control unit 401 and outputs them to the mapping unit 403. The signal generation unit 402 can be composed of a signal generator, signal generation circuit, or signal generation device that is commonly known in the art to which this invention pertains.

[0131] The signal generation unit 402 generates a UL data channel based on instructions from the control unit 401. For example, if the UL license is included in the DL control channel notified from the wireless base station 10, the signal generation unit 402 is instructed from the control unit 401 to generate a UL data channel.

[0132] Based on instructions from the control unit 401, the mapping unit 403 maps the UL signal generated in the transmission signal generation unit 402 to wireless resources and outputs it to the transmission and reception unit 203. The mapping unit 403 can be composed of a mapper, mapping circuit, or mapping device described based on common knowledge in the art to which this invention pertains.

[0133] Mapping unit 403, for example Figure 5 As shown, the random access preamble is mapped to radio resources. Specifically, the mapping unit 403, as shown... Figure 5 As shown, the random access preamble is mapped to radio resources by time multiplexing and / or frequency multiplexing.

[0134] The receiving signal processing unit 404 performs receiving processing (e.g., demapping, demodulation, decoding, etc.) on the received signal input from the transmitting / receiving unit 203. Here, the received signal is a DL signal (DL control channel, DL data channel, DL reference signal, etc.) transmitted from, for example, the wireless base station 10. The receiving signal processing unit 404 can be configured as a signal processor, signal processing circuit, or signal processing apparatus described based on common knowledge in the art to which this invention pertains. Furthermore, the receiving signal processing unit 404 can constitute the receiving unit according to this invention.

[0135] Based on the instructions of the control unit 401, the receiving signal processing unit 404 performs blind decoding of the DL control channel for scheduling the transmission and / or reception of the DL data channel, and performs receiving processing of the DL data channel based on the DCI. Furthermore, the receiving signal processing unit 404 estimates the channel gain based on DM-RS or CRS, and demodulates the DL data channel based on the estimated channel gain.

[0136] The receiving signal processing unit 404 outputs the decoded information obtained through receiving and processing to the control unit 401. The receiving signal processing unit 404 can also output information such as broadcast information, system information, RRC signaling, and DCI to the control unit 401. Furthermore, the receiving signal processing unit 404 can output the data decoding result to the control unit 401. Additionally, the receiving signal processing unit 404 outputs the received signal, or the received and processed signal, to the measurement unit 405.

[0137] The measurement unit 405 performs measurements related to the received signal. The measurement unit 405 can be composed of a measuring instrument, measuring circuit, or measuring device described based on common knowledge in the technical field to which this invention pertains.

[0138] The measurement unit 405 can also measure, for example, the received power (e.g., RSRP) of the received signal, the DL received quality (e.g., RSRQ), or the channel state. The measurement results can also be output to the control unit 401.

[0139] <Hardware Structure>

[0140] It should be noted that the block diagrams used in the above embodiments illustrate functional units. These functional blocks (structural units) can be implemented by any combination of hardware and / or software. Furthermore, there are no particular limitations on the means of implementing each functional block. That is, each functional block can be implemented by a single device that is physically and / or logically combined, or by directly and / or indirectly (e.g., wired and / or wirelessly) connecting two or more physically and / or logically separate devices.

[0141] For example, the base station and user equipment in this embodiment can also function as computers for processing the wireless communication method of the present invention. Figure 11 This diagram illustrates an example of the hardware structure of the wireless base station and user terminal according to this embodiment. The base station 10 and user terminal 20 described above can be configured as a computer device that physically includes a processor 1001, a memory 1002, a storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0142] It should be noted that in the following description, the term "device" can be replaced with circuit, equipment, unit, etc. The hardware structure of the wireless base station 10 and the user terminal 20 can be configured to include one or more of the devices shown in the figures, or it can be configured to exclude some of the devices.

[0143] For example, only one processor 1001 is illustrated, but there can also be multiple processors. Furthermore, processing can be executed by one processor, or processing can be executed simultaneously, sequentially, or by more than one processor using other means. It should be noted that processor 1001 can also be installed using more than one chip.

[0144] The functions of the wireless base station 10 and the user terminal 20 are realized by reading the prescribed software (program) into the hardware such as the processor 1001 and the memory 1002, the processor 1001 performs calculations, and controls the communication based on the communication device 1004, or the reading and / or writing of data in the memory 1002 and the storage device 1003.

[0145] The processor 1001, for example, enables the operating system to operate, thereby controlling the computer as a whole. The processor 1001 may also be composed of a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic devices, registers, etc. For example, the baseband signal processing unit 104 (204) and call processing unit 105 described above can also be implemented by the processor 1001.

[0146] Furthermore, the processor 1001 can read programs (program code), software modules, or data from the storage 1003 and / or communication device 1004 into the memory 1002, and perform various processes accordingly. As a program, a program is used to cause the computer to perform at least a portion of the operations described in the above embodiments. For example, the control unit 401 of the user terminal 20 can also be implemented by a control program housed in the memory 1002 and operated by the processor 1001; similarly, other functional blocks can be implemented.

[0147] The memory 1002 is a computer-readable recording medium and may be composed of at least one of, for example, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), or other suitable storage media. The memory 1002 may also be referred to as a register, cache, main memory (main storage device), etc. The memory 1002 is capable of storing programs (program code), software modules, etc., that are executable for implementing the wireless communication method according to one embodiment of the present invention.

[0148] Storage device 1003 is a computer-readable recording medium that may be composed of at least one of the following: flexible disk, floppy disk (registered trademark), optical disk (e.g., compact disc ROM), digital versatile optical disk, Blu-ray optical disk (registered trademark), removable optical disk, hard disk drive, smart card, flash memory (e.g., card, stick, key drive), magnetic tape, database, server, or other suitable storage media. Storage device 1003 may also be referred to as an auxiliary storage device.

[0149] The communication device 1004 is hardware (transmitting and receiving device) used for communication between computers via wired and / or wireless networks, and is also referred to as a network device, network controller, network interface card (NIC), communication module, etc. To implement, for example, frequency division duplex (FDD) and / or time division duplex (TDD), the communication device 1004 may also include high-frequency switches, duplexers, filters, frequency synthesizers, etc. For example, the aforementioned transmit / receive antenna 101 (201), amplifier unit 102 (202), transmit / receive unit 103 (203), transmission path interface 106, etc., can be implemented through the communication device 1004.

[0150] Input device 1005 is an input device that accepts input from external sources (e.g., keyboard, mouse, microphone, switch, button, sensor, etc.). Output device 1006 is an output device that performs output to external sources (e.g., monitor, speaker, LED (Light Emitting Diode) lamp, etc.). It should be noted that input device 1005 and output device 1006 can also be integrated into a single structure (e.g., touch panel).

[0151] Furthermore, devices such as processor 1001 or memory 1002 are connected via bus 1007 for communication information. Bus 1007 may be a single bus or may be composed of different buses between devices.

[0152] Furthermore, the wireless base station 10 and the user terminal 20 may also be constructed using hardware such as microprocessors, digital signal processors (DSPs), ASICs (Application Specific Integrated Circuits), PLDs (Programmable Logic Devices), and FPGAs (Field Programmable Gate Arrays), and may implement some or all of the functional blocks through such hardware. For example, the processor 1001 may also be installed using at least one of these hardware components.

[0153] (Modified Example)

[0154] It should be noted that the terms used in this specification and / or those necessary for understanding this specification may be replaced with terms that have the same or similar meanings. For example, a channel and / or symbol may also be a signal (signaling). Furthermore, a signal may also be a message. A reference signal may also be simply referred to as RS (Reference Signal), and depending on the applied standard, may also be called a pilot, pilot signal, etc. Additionally, a component carrier (CC) may also be referred to as a cell, frequency carrier, carrier frequency, etc.

[0155] Furthermore, a radio frame can also be composed of one or more periods (frames) in the time domain. Each of these periods (frames) constituting a radio frame can also be called a subframe. Further, a subframe can also be composed of one or more time slots in the time domain. Further, a time slot can also be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain.

[0156] Radio frames, subframes, time slots, and symbols all represent time units for transmitting signals. Radio frames, subframes, time slots, and symbols can also be referred to by their corresponding other names. For example, one subframe can be called a Transmission Time Interval (TTI), multiple consecutive subframes can be called a TTI, and one time slot can also be called a TTI. That is, a subframe or TTI can be a subframe in existing LTE (1ms), a period shorter than 1ms (e.g., 1-13 symbols), or a period longer than 1ms.

[0157] Here, TTI refers to the smallest unit of time for scheduling, such as in wireless communication. For example, in an LTE system, the wireless base station allocates wireless resources (such as bandwidth or transmission power available to each user terminal) to each user terminal in TTI units. It should be noted that the definition of TTI is not limited to this. TTI can be the transmission time unit of data packets (transmission blocks) after channel coding, or it can be a processing unit such as scheduling or link adaptation.

[0158] A TTI with a duration of 1ms can also be referred to as a normal TTI (TTI in LTE Rel.8-12), a long TTI, a normal subframe, or a long subframe, etc. A TTI shorter than a normal TTI can also be referred to as a shortened TTI, a short TTI, a shortened subframe, or a short subframe, etc.

[0159] A resource block (RB) is a unit of resource allocation in the time and frequency domains. In the frequency domain, it can contain one or more consecutive subcarriers. Furthermore, in the time domain, an RB can contain one or more symbols, and can also be the length of a time slot, a subframe, or a time interval time series (TTI). A TTI and a subframe can each be composed of one or more resource blocks. It should be noted that RBs can also be called physical resource blocks (PRBs), PRB pairs, RB pairs, etc.

[0160] In addition, a resource block can also consist of one or more resource elements (REs). For example, one RE can also be a radio resource area consisting of one subcarrier and one symbol.

[0161] It should be noted that the structures of radio frames, subframes, time slots, and symbols described above are merely illustrative. For example, the number of subframes contained in a radio frame, the number of time slots contained in a subframe, the number of symbols and RBs contained in a time slot, the number of subcarriers contained in an RB, and the number of symbols, symbol length, and cyclic prefix (CP) length within a TTI can be modified in various ways.

[0162] Furthermore, the information and parameters described in this specification may be expressed in absolute values, relative values ​​calculated from a specified value, or other corresponding information. For example, wireless resources may also be indicated by a specified index. Furthermore, the mathematical formulas used to employ these parameters may differ from those explicitly disclosed in this specification.

[0163] The names used for parameters, etc., in this specification are not limiting in any way. For example, various channels (PUCCH (Physical Uplink Control Channel), PDCCH (Physical Downlink Control Channel), etc.) and information elements can be identified by any appropriate name, and therefore the various names assigned to these various channels and information elements are not limiting at any point.

[0164] The information, signals, etc., described in this specification can also be represented using a wide variety of different and arbitrary techniques. For example, data, commands, instructions, information, signals, bits, symbols, chips, etc., that may be mentioned throughout the foregoing description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

[0165] Furthermore, information and signals can be output from a higher level (higher layer) to a lower level (lower layer), and / or from a lower level (lower layer) to a higher level (higher layer). Information and signals can also be input and output via multiple network nodes.

[0166] Input and output information and signals can be stored in a specific location (such as memory) or managed using a management table. Input and output information and signals can also be overwritten, updated, or appended. Output information and signals can be deleted. Input information and signals can also be sent to other devices.

[0167] The notification of information is not limited to the methods / implementations described in this specification, and may also be carried out by other methods. For example, the notification of information may also be implemented through physical layer signaling (e.g., downlink control information (DCI), uplink control information (UCI)), higher layer signaling (e.g., RRC (Radio Resource Control) signaling), broadcast information (Master Information Block (MIB), System Information Block (SIB), etc.), MAC (Medium Access Control) signaling), other signals, or combinations thereof.

[0168] It should be noted that physical layer signaling can also be referred to as L1 / L2 (Layer 1 / Layer 2) control information (L1 / L2 control signals), L1 control information (L1 control signals), etc. Furthermore, RRC signaling can also be referred to as RRC messages, or for example, RRC connection setup messages (RRCConnectionSetup) messages, RRC connection reconfiguration messages (RRCConnectionReconfiguration), etc. Additionally, MAC signaling can also be communicated through, for example, MAC control elements (MAC CE (Control Element)).

[0169] Furthermore, the notification of the prescribed information (such as a notification of "for X") is not limited to being explicit, but can also be implicit (e.g., by not providing the prescribed information, or by providing other information).

[0170] The determination can be made by the value represented by a single bit (0 or 1), by a true or false value (Boolean), or by a numerical comparison (e.g., by comparing with a specified value).

[0171] Software, whether called software, firmware, middleware, microcode, hardware description language, or by other names, should be broadly interpreted as meaning command, command set, code, code segment, program code, program, subroutine, software module, application, software application, software package, routine, subroutine, project, executable file, executable thread, procedure, function, etc.

[0172] Furthermore, software, commands, and information can be sent and received via transmission media. For example, when software is sent from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, and digital subscriber line (DSL)) and / or wireless technologies (such as infrared and microwave), these wired and / or wireless technologies are included within the definition of transmission media.

[0173] The terms “system” and “network” used in this specification are interchangeable.

[0174] In this manual, the terms "base station (BS)," "wireless base station," "eNB," "cell," "sector," "cell group," "carrier," and "component carrier" are used interchangeably. Base stations are sometimes also referred to as fixed stations, NodeBs, eNodeBs (eNBs), access points, transmitting points, receiving points, femtocells, and small cells.

[0175] A base station can accommodate one or more (e.g., three) cells (also known as sectors). When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, each of which can also provide communication services through a base station subsystem (e.g., a small indoor base station RRH: Remote Radio Head). The terms "cell" or "sector" refer to a portion or the entire coverage area of ​​the base station and / or base station subsystem that provides communication services within that coverage area.

[0176] In this manual, the terms "Mobile Station (MS)," "User Terminal," "User Equipment (UE)," and "Terminal" are used interchangeably. Base stations are sometimes also referred to by terms such as fixed station, NodeB, eNodeB (eNB), access point, transmitting point, receiving point, femtocell, and small cell.

[0177] Mobile station is sometimes referred to by those skilled in the art as subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or a variety of other suitable terms.

[0178] Furthermore, the wireless base station described in this specification can also be replaced by a user terminal. For example, various methods / implementations of the present invention can be applied to a structure where communication between the wireless base station and the user terminal is replaced by communication between multiple user terminals (D2D: Device-to-Device). In this case, the functions of the wireless base station 10 described above can also be implemented as those of the user terminal 20. Furthermore, terms such as "uplink" or "downlink" can be replaced with "side". For example, the uplink channel can be replaced with the side channel.

[0179] Similarly, the user terminal described in this specification can also be replaced by a wireless base station. In this case, the functions of the user terminal 20 described above can also be implemented using the structure of the wireless base station 10.

[0180] In this specification, certain operations described as being performed via a base station may sometimes be performed via its upper node, depending on the circumstances. Clearly, in a network consisting of one or more network nodes with base stations, various operations for communicating with terminals can be performed via the base station, one or more network nodes other than the base station (e.g., an MME (Mobility Management Entity), an S-GW (Serving-Gateway), etc., but not limited to these), or combinations thereof.

[0181] The various methods / executives described in this specification can be used individually, in combination, or switched during execution. The processing order, timing, flowcharts, etc., of the various methods / executives described in this specification can be rearranged unless there are contradictions. For example, various steps are illustrated in a specific order for the methods described in this specification, and are not limited to the indicated order.

[0182] The methods / implementations described in this specification can also be applied to LTE (Long Term Evolution), LTE-A (LTE-Advanced), LTE-B (LTE-Beyond), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), New-RAT (Radio Access Technology), NR (New Radio), NX (New radio access), FX (Future generation radio access), GSM (Global System for Mobile Communications), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), and IEEE 802.20, UWB (Ultra-Wideband), Bluetooth (registered trademark), systems utilizing other suitable wireless communication methods, and / or next-generation systems based on these.

[0183] The term "based on" as used in this specification, unless otherwise specified, does not mean "based on only". In other words, the term "based on" means both "based on only" and "based on at least".

[0184] Any reference to elements referred to as "the first," "the second," etc., as used in this specification is not intended to define the quantity or order of these elements holistically. These designations may be used in this specification as a convenient way to distinguish between two or more elements. Therefore, reference to the first and second elements does not imply that only two elements can be used, or that the first element must take precedence over the second element in some way.

[0185] The term "determining" as used in this specification sometimes encompasses a wide variety of operations. For example, "determining" can refer to actions such as calculating, computation, processing, deriving, investigating, looking up (e.g., searching in a table, database, or other data structure), and ascertaining. Furthermore, "determining" can also refer to receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, and accessing (e.g., accessing data in memory). Additionally, "determining" can refer to resolving, selecting, choosing, establishing, and comparing. In short, any operation can be considered as "determining."

[0186] The terms “connected,” “coupled,” or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, including the presence of one or more intermediate elements between the two elements that are “connected” or “coupled.” The coupling or connection between elements can be physical, logical, or a combination thereof. As used in this specification, it can be considered that two elements are “connected” or “coupled” by using electromagnetic energy, such as electromagnetic energy with wavelengths in the wireless frequency domain, microwave region, and light (both visible and invisible) region, through the use of one or more wires, cables, and / or printed electrical connections, and as multiple non-limiting and non-inclusive examples, through the use of electromagnetic energy.

[0187] When used in this specification or claims, the terms “include,” “comprising,” and variations thereof, like the term “possess,” refer to inclusion. Furthermore, the term “(or)” as used in this specification or claims does not refer to XOR.

[0188] The present invention has been described in detail above, but it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be implemented in modified and altered ways without departing from the spirit and scope of the invention as defined by the patent claims. Therefore, the description in this specification is for illustrative purposes and is not intended to be restrictive in any way.

[0189] This application is based on Japanese Special Petition 2016-140715, filed on July 15, 2016. Its entire contents are contained herein.

Claims

1. A terminal, characterized by comprising: have: The control unit controls the random access procedure within the cell; and The transmitting unit transmits a random access preamble using the first subcarrier interval and a UL data channel using the second subcarrier interval. The control unit determines the first subcarrier interval based on first information representing the first subcarrier interval, and determines the second subcarrier interval based on second information representing the second subcarrier interval. Regarding the random access preamble used in the first subcarrier interval, several preamble formats are specified. The terminal also has: The receiving unit receives information for identifying the preamble format among the plurality of preamble formats via higher-layer signaling.

2. The terminal according to claim 1, characterized in that, The receiving unit receives first information representing the first subcarrier interval and second information representing the second subcarrier interval via higher-layer signaling.

3. The terminal according to claim 1 or claim 2, characterized in that, The transmitting unit repeatedly transmits a random access preamble with a subcarrier interval specified by the application.

4. The terminal according to claim 1 or claim 2, characterized in that, It supports the transmission of random access preambles with a first subcarrier spacing of 1.25 kHz and a sequence number of 839, as well as random access preambles with a first subcarrier spacing of 5 kHz and a sequence number of 839.

5. The terminal according to claim 1 or claim 2, characterized in that, The control unit selects a random access preamble associated with the subcarrier interval based on specified conditions.

6. The terminal according to claim 1 or claim 2, characterized in that, The transmitting unit uses a pre-set bandwidth to transmit the random access preamble.

7. A wireless communication method of a terminal, the method comprising: have: The steps involved in controlling the random access procedure in a cell; and The steps of transmitting a random access preamble using the first subcarrier interval and a UL data channel using the second subcarrier interval. The first subcarrier interval is determined based on first information representing the first subcarrier interval, and the second subcarrier interval is determined based on second information representing the second subcarrier interval. Regarding the random access preamble used in the first subcarrier interval, several preamble formats are specified. The wireless communication method further has the following characteristics: The step of receiving information via higher-layer signaling for identifying the preamble format among the plurality of preamble formats.

8. A base station, characterized by have: The control unit controls the random access procedure within the cell; and The receiving unit receives a random access preamble using the first subcarrier interval and a UL data channel using the second subcarrier interval. The control unit determines the first subcarrier interval based on first information representing the first subcarrier interval, and determines the second subcarrier interval based on second information representing the second subcarrier interval. Regarding the random access preamble used in the first subcarrier interval, several preamble formats are specified. The base station also has: The transmitting unit transmits information for identifying the preamble format among the plurality of preamble formats via higher-layer signaling.

9. A wireless communication system having a terminal and a base station, characterized in that, The terminal has: The terminal control unit controls the random access procedure within the cell; and The terminal transmitting unit transmits a random access preamble using the first subcarrier interval and a UL data channel using the second subcarrier interval. The terminal control unit determines the first subcarrier interval based on first information representing the first subcarrier interval, and determines the second subcarrier interval based on second information representing the second subcarrier interval. Regarding the random access preamble used in the first subcarrier interval, several preamble formats are specified. The terminal also has: The terminal receiving unit receives information via higher-layer signaling for identifying the preamble format among the plurality of preamble formats. The base station has: The base station control unit controls the random access process within a cell; and The base station receiving unit receives a random access preamble using the first subcarrier interval and a UL data channel using the second subcarrier interval. The base station control unit determines the first subcarrier interval based on first information representing the first subcarrier interval, and determines the second subcarrier interval based on second information representing the second subcarrier interval. Regarding the random access preamble used in the first subcarrier interval, several preamble formats are specified. The base station also has: The transmitting unit transmits information for identifying the preamble format among the plurality of preamble formats via higher-layer signaling.

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