Communication Systems

Abstract

To provide a master station device capable of efficiently reducing communication traffic volume between a master station device and a slave station device.SOLUTION: A master station device 11 includes: a first base station signal processing unit 202-1 that has a first functional division configuration for a first service type; and a second base station signal processing unit 202-2 that has a second functional division configuration for a second service type.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to Communication Systems Regarding. [Background technology]

[0002] In a wireless communication system, in order to flexibly create areas where wireless communication with user equipment (UE) is possible, it is possible to adopt a configuration in which a wireless base station is divided into a master station device and a slave station device, and the slave station device is placed in a location different from the master station device.

[0003] For example, a master station device connected to a core network is provided with a baseband signal processing function of a wireless base station, and one or more slave station devices are connected to the master station device. The slave station device performs wireless processing such as analog conversion and performs wireless communication with UEs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-170805 A [Patent Document 2] International Publication No. 2016 / 088820 [Patent Document 3] JP 2016-111637 A [Non-patent literature]

[0005] [Non-Patent Document 1] Common Public Radio Interface (CPRI) Interface Specification V7.0 (2015-10-09) [Non-Patent Document 2] Common Public Radio Interface: eCPRI Interface Specification V2.0 (2019-05-10) [Non-Patent Document 3] ITU-T G-series Recommendations - Supplement 66 (2018-10) Summary of the Invention [Problem to be solved by the invention]

[0006] However, in existing wireless communication systems (for example, wireless base stations), there is room for consideration regarding reduction of the amount of communication traffic between a master station device and a slave station device.

[0007] A non-limiting embodiment of the present disclosure contributes to providing a master station device, a slave station device, and a communication control method that can efficiently reduce the amount of communication traffic between the master station device and the slave station device. [Means for solving the problem]

[0008] A parent station device according to one embodiment of the present disclosure is a parent station device connected to a child station device via a fronthaul, and includes a first base station signal processing unit having a first functional division configuration for a plurality of base station function units for a first service type, a second base station signal processing unit having a second functional division configuration for the plurality of base station function units for a second service type, and a control unit that controls the fronthaul transmission method of the first base station signal processing unit in accordance with the first functional division configuration and controls the fronthaul transmission method of the second base station signal processing unit in accordance with the second functional division configuration, wherein when the first functional division configuration includes an upper physical layer and the second functional division configuration does not include an upper physical layer, the control unit controls the transmission method of the first base station signal processing unit in fronthaul transmission to the child station device to be a fronthaul transmission with lower redundancy than the transmission method of the second base station signal processing unit.

[0009] A slave station device according to one embodiment of the present disclosure is a slave station device connected to a master station device via a fronthaul, and includes a first base station signal processing unit having a first functional division configuration for a plurality of base station function units for a first service type, a second base station signal processing unit having a second functional division configuration for the plurality of base station function units for a second service type, and a control unit that controls the fronthaul transmission method of the first base station signal processing unit in accordance with the first functional division configuration and controls the fronthaul transmission method of the second base station signal processing unit in accordance with the second functional division configuration, wherein when the first functional division configuration does not include an upper physical layer and the second functional division configuration includes an upper physical layer, a fronthaul transmission having a lower redundancy than the transmission method of the second base station signal processing unit is applied to the transmission method of the first base station signal processing unit in fronthaul transmission from the master station device.

[0010] A communication control method according to one embodiment of the present disclosure is a communication control method of a parent station device connected to a child station device via a fronthaul, the parent station device including a first base station signal processing unit having a first functional division configuration for a first service type and a second base station signal processing unit having a second functional division configuration for the plurality of base station function units for a second service type, the method comprising: acquiring information indicating transmission quality of the fronthaul; controlling the fronthaul transmission method of the first base station signal processing unit in accordance with the first functional division configuration; controlling the fronthaul transmission method of the second base station signal processing unit in accordance with the second functional division configuration; and applying a fronthaul transmission method having lower redundancy than the transmission method of the second base station signal processing unit to the transmission method of the first base station signal processing unit in fronthaul transmission to the child station device when the first functional division configuration includes an upper physical layer and the second functional division configuration does not include an upper physical layer.

[0011] A communication control method according to one embodiment of the present disclosure is a communication control method for a slave station device connected to a master station device via a fronthaul, the slave station device including a first base station signal processing unit having a first functional division configuration for a first service type and a second base station signal processing unit having a second functional division configuration for the plurality of base station function units, the master station device transmitting a signal for measuring transmission quality of the fronthaul, controlling a fronthaul transmission method of the first base station signal processing unit in accordance with the first functional division configuration, and controlling the fronthaul transmission method of the second base station signal processing unit in accordance with the second functional division configuration, wherein when the first functional division configuration does not include an upper physical layer and the second functional division configuration includes an upper physical layer, a fronthaul transmission method having lower redundancy than the transmission method of the second base station signal processing unit is applied to the transmission method of the first base station signal processing unit in fronthaul transmission from the master station device.

[0012] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. Effect of the Invention

[0013] According to one aspect of the present disclosure, the amount of communication traffic between a master station device and a slave station device can be efficiently reduced.

[0014] Further advantages and benefits of certain aspects of the present disclosure will become apparent from the specification and drawings, in which such advantages and / or benefits are provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of which are provided to obtain one or more identical features. [Brief description of the drawings]

[0015] [Figure 1]FIG. 1 is a diagram showing an example of a configuration of a wireless communication system according to a first embodiment; [Diagram 2] FIG. 1 is a block diagram showing an example of a configuration of a master station processing device according to a first embodiment; [Diagram 3] FIG. 1 is a block diagram showing an example of the configuration of a fronthaul (FH) transmitter according to a first embodiment; [Figure 4] FIG. 1 is a block diagram showing an example of the configuration of an FH receiver according to a first embodiment; [Diagram 5] FIG. 1 is a block diagram showing an example of a configuration of a slave station processing device according to a first embodiment; [Figure 6] FIG. 1 is a sequence diagram showing an example of an operation of the wireless communication system according to the first embodiment. [Figure 7] FIG. 11 is a block diagram showing an example of the configuration of a master station processing device provided in a master station device according to a second embodiment; [Figure 8] FIG. 11 is a block diagram showing an example of the configuration of an FH transmitter provided in a master station according to a second embodiment. [Figure 9] FIG. 11 is a sequence diagram showing an example of an operation of the wireless communication system according to the second embodiment. [Figure 10] FIG. 11 is a block diagram showing an example of the configuration of an FH receiver provided in a slave station device according to a third embodiment. [Figure 11] FIG. 11 is a sequence diagram showing an example of an operation of a wireless communication system according to a third embodiment. [Figure 12] FIG. 13 is a diagram showing an example of a configuration of a wireless communication system according to a fourth embodiment. [Figure 13] FIG. 13 is a block diagram showing an example of the configuration of a slave station processing device provided in a slave station device according to a fourth embodiment; [Figure 14] FIG. 13 is a block diagram showing an example of the configuration of an FH transmitter provided in a slave station device according to a fourth embodiment. [Figure 15] FIG. 13 is a block diagram showing an example of the configuration of an FH receiver provided in a master station according to a fourth embodiment. [Figure 16] FIG. 13 is a block diagram showing an example of the configuration of a master station processing device provided in a master station device according to a fourth embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] (Findings that led to this disclosure) In existing technology (for example, Patent Document 1), a master station device is sometimes called a BBU (baseband unit), and a slave station device is sometimes called an RRH (remote radio head). A wired transmission means (or a wired interface) such as a coaxial cable, a UTP (unshielded twisted pair) cable, an STP (shielded twisted pair) cable, or an optical fiber cable is used for the connection between the master station device and the slave station device. Such a connection between the master station device and the slave station device is sometimes called a "fronthaul connection" or simply a "fronthaul".

[0017] In the regulations relating to the communication method of the fronthaul (FH) (for example, Non-Patent Document 1), the master station device is called a REC (radio equipment controller), and the slave station device is called an RE (radio equipment).

[0018] As wireless communication becomes faster and larger in capacity, the amount of FH communication (for example, data traffic) also increases, which may cause the FH communication band to become congested.

[0019] As an example of a measure against the FH bandwidth shortage, a reduction in the FH traffic volume is being considered by changing the conventional configuration to one in which multiple base station functions are divided (or separated) into a master station device and a slave station device (for example, Patent Document 1). Note that the boundary at which multiple base station functions are divided into a master station device and a slave station device is sometimes called a "functional split point."

[0020] For example, instead of a functional division configuration in which the slave station device has the up-conversion function and the amplification function, and the master station device has the base station functions of the up-conversion function and the amplification function, the following functional division configuration is considered. Note that the "functional division configuration" may be called a "functional division architecture."

[0021] ·Slave station device buffer PDCP (packet data convergence protocol) RLC (radio link control) MAC (medium access control) encoding modulation Resource Mapping IFFT (inverse fast Fourier transform) Up-conversion

[0022] ·Master station device Bearer Termination Function

[0023] Here, the closer to transmission the process, the larger the data volume becomes because the number of data headers and redundancy increases. By increasing the number of functions allocated to the master station equipment rather than the slave station equipment as described above, the amount of communication from the master station equipment to the slave station equipment, i.e., the amount of FH communication, can be reduced. Note that Non-Patent Document 2 also considers changing the division of functions between the master station equipment and the slave station equipment.

[0024] Also, it is being considered to divide control data and user data and apply functional division between different master station equipment and slave station equipment for each data (for example, Patent Document 2). By allocating more functions to the master station equipment for user data, which tends to be larger in volume than control data, it is possible to reduce the amount of FH communication.

[0025] Also, a method of changing user assignment and resource assignment for wireless communication according to availability of the FH band is being considered (for example, Patent Document 3). For example, by preparing several patterns for user assignment and resource assignment for wireless communication and applying a pattern that fits within the FH band, it is possible to avoid congestion of the FH band.

[0026] However, applying a pattern that fits within the FH band in this way imposes restrictions on the FH band, which may lead to a decrease in system performance. Also, when the functional division configuration between the master station equipment and the slave station equipment is changed, the system performance may differ depending on the functional division configuration. Therefore, it may not be possible to say that the system performance is optimized for the service type of the data to be transmitted.

[0027] For example, the MAC function determines and controls a transmission method for wireless transmission in response to channel quality information (e.g., channel quality indicator, CQI) fed back from the UE. The transmission method for wireless transmission may include determining a modulation and coding scheme (MCS), in other words, determining transmission parameters such as a coding rate and a modulation multi-level number. In addition, the MAC function performs retransmission control called hybrid automatic repeat request (HARQ) in response to acknowledgement (Ack / Nack) information fed back from the UE.

[0028] When the MAC function that handles such control is placed in the master station, for example, cooperative operation between multiple different slave station devices connected to the master station is possible. This makes it possible to improve the signal-to-interference plus noise power ratio (SINR) of the wireless communication section. Communication using such cooperative operation is called CoMP (coordinated multiple-point) communication or antenna cooperation.

[0029] In contrast, if the MAC function is placed in the slave station equipment, for example, HARQ retransmission control can be realized without going through the FH (e.g., the optical transmission section), so the RTT (round trip time) can be shortened by the round trip time of the FH, making it possible to reduce latency.

[0030] Such differences in system performance due to differences in functional division configurations have not been taken into consideration or examined up until now. Therefore, when a radio base station adopts a plurality of different functional division configurations, the difference in performance or capability that occurs in FH transmission due to the functional division configuration has not been taken into consideration or examined.

[0031] For example, the type of signal (e.g., data) flowing through the FH (in other words, the output of which base station function flows) may differ depending on the difference in functional division configuration between the master station device and the slave station device. If the type of data flowing through the FH differs, the suitable or optimal FH transmission means will also differ, and for example, data may have excessive redundancy in the FH transmission.

[0032] (Summary of the Disclosure) Based on the above findings, the present disclosure describes, for example, the following techniques.

[0033] (1) The functional division configuration of the base station equipment (master station equipment and slave station equipment) is made different depending on the service type. (2) Controlling (e.g., making different) the transmission method in the fronthaul transmission between the master station device and the slave station device according to the functional division configuration. Controlling the transmission method in the FH transmission may include, for example, determining or controlling at least one of the error correction code, the coding rate, and the modulation method. (3) Notify (eg, provide feedback to) the master station device of the transmission quality in FH transmission. (4) The master station device controls the wireless transmission method based on the information on the wireless transmission quality and the information on the service type and the FH transmission quality. The control of the wireless transmission method may include, for example, determining or controlling at least one of an error correction code, a coding rate, and a modulation method. (5) In FH transmission, signal redundancy is reduced by allowing degradation of signal quality (in other words, for example, allowing data loss to occur in FH transmission). Reducing signal redundancy in FH transmission makes it possible to reduce the traffic volume of FH transmission. In controlling the wireless transmission method in (4) above, the signal distortion allowed for FH transmission is taken into account or factored in, thereby ensuring the transmission quality of the wireless communication system (hereinafter sometimes simply referred to as the "system").

[0034] Hereinafter, the embodiments will be described with reference to the drawings as appropriate. Note that more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

[0035] It should be noted that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0036] (Embodiment 1) Fig. 1 is a diagram showing an example of a configuration of a wireless communication system according to embodiment 1. As illustrated in Fig. 1, the wireless communication system includes, for example, a wireless base station 1 and a UE 2 which is an example of a terminal device. The number of the wireless base stations 1 and the number of the UE 2 may each be two or more.

[0037] The UE 2 wirelessly connects to the wireless base station 1 and communicates with it. The wireless communication between the UE 2 and the wireless base station 1 includes at least one of uplink (UL) communication and downlink (DL) communication. In the following, an example of the configuration and operation of the wireless base station 1 focusing on DL will be described. Examples focusing on UL will be described later in embodiments 4 to 6 (FIGS. 12 to 16).

[0038] The wireless base station 1 includes, for example, a master station device 11 and a slave station device 12 connected to each other by an FH 13. The master station device 11 may be referred to as, for example, a BBU, a centralized baseband unit (CBBU), a REC, or a central unit (CU). The slave station device 12 may be referred to as, for example, an RRH, a RE, or a distributed unit (DU). Note that one master station device may be connected to two or more slave station devices. Also, one slave station device may be connected to two or more UEs.

[0039] For example, a wired transmission means (or a wired interface) such as a UTP cable, an STP cable, or an optical fiber cable may be applied to the FH13. The wired interface may be an interface conforming to a standard or technology such as CPRI (common public radio interface), eCPRI (evolved CPRI), OBSAI (open base station architecture initiative), RoE (radio over Ethernet), or RoF (radio over fiber). Note that "Ethernet" is a registered trademark.

[0040] <Master station device 11> For example, the master station device 11 includes a master station processing device 20 and an FH transmitter 30, and the slave station device 12 includes an FH receiver 40 and a slave station processing device 50. Fig. 2 shows an example of the configuration of the master station processing device 20, and Fig. 3 shows an example of the configuration of the FH transmitter 30. Fig. 4 shows an example of the configuration of the FH receiver 40, and Fig. 5 shows an example of the configuration of the slave station processing device 50.

[0041] (Master station processing device 20) As shown in FIG. 2, the master station processing device 20 includes a service class separator 201, master station signal processing units 202-1 and 202-2, a multiplex unit 203, and an FH quality calculate unit 204.

[0042] The master station signal processing units 202-1 and 202-2 may be written as master station signal processing units 202#1 and 202#2, respectively. When the master station signal processing units 202-1 and 202-2 are not to be distinguished from each other, they may be written as master station signal processing units 202. The number of master station signal processing units 202 provided in the master station processing device 20 is not limited to two, and may be three or more. For example, assuming that N is an integer equal to or greater than two, the N master station signal processing units 202 may be written as master station signal processing units 202#j (j=1 to N). It should be noted that N may correspond to the number of service types.

[0043] The service class separation unit 201, for example, separates a signal (e.g., user data) sent from a higher-level core network (e.g., EPC or 5GC) by service type. "EPC" is an abbreviation for "evolved packet core," and 5GC is an abbreviation for "5th generation (5G) core network."

[0044] 5G stands for fifth generation radio access technology (RAT) and is sometimes written as NR (new radio). 5GC is sometimes written as NGC (next generation core network).

[0045] The arrangement position of the service class separator 201 illustrated in Fig. 2 is not limited to the position (before the SDAP unit 2021) illustrated in Fig. 2. For example, the service class separator 201 may be arranged after the SDAP unit 2021 or after the PDCP unit 2022, which will be described later.

[0046] Non-limiting examples of service types include enhanced mobile broadband (eMBB), ultra-reliable and low latency communications (URLLC), and massive machine type communication (mMTC), which are requirements for 5G. User data may be divided (or classified) according to these service types.

[0047] Additionally or alternatively, the user data may be classified according to quality of service (QoS) parameters defined for each data flow, which may include, for example, any one or more of allocation and retention priority (ARP), guaranteed bit rate (GBR), maximum bit rate (MBR), and 5G QoS Identifier (5QI).

[0048] Additionally or alternatively, the user data may be categorized according to different services of the application.

[0049] 2, the master station signal processing unit 202#1 corresponding to the service type #1 includes, for example, a service data adaptation protocol (SDAP) unit 2021, a packet data convergence protocol (PDCP) unit 2022, a radio link control (RLC) unit 2023, and a MAC unit 2024. The master station signal processing unit 202#1 also includes, for example, an encoding unit 2025, a scrambling unit 2026, a modulation unit 2027, a layer mapping unit 2028, a precoding unit 2029, and a resource element (RE) mapping unit 2030.

[0050] These functional units 2021 to 2030, together with functional units 5029 and 5030 in a slave station signal processing unit 502#1 described later with reference to Fig. 5, are non-limiting examples of a plurality of base station functional units included in the wireless base station 1. The encoding unit 2025, the scrambling unit 2026, the modulation unit 2027, the layer mapping unit 2028, the precoding unit 2029, and the RE mapping unit 2030 form a higher physical layer (High-PHY) block 2001.

[0051] The SDAP section 2021 performs, for example, mapping between a QoS flow and a radio bearer, and adds an SDAP header to a packet sent from a higher-level core network, and outputs the packet to the PDCP section 2022 .

[0052] The PDCP section 2022 performs processes such as encryption and header compression of user data on the output of the SDAP section 2021 , and outputs a PDCP protocol data unit (PDU) to the RLC section 2023 .

[0053] The RLC section 2023 performs processing such as error detection and retransmission control using ARQ on the output of the PDCP section 2022, and outputs an RLC PDU.

[0054] The MAC unit 2024 performs retransmission control using HARQ, determines UEs 2 to which communication opportunities are assigned using scheduling, and determines the MCS for wireless transmission, generates a MAC PDU from an RLC PDU, and outputs a transport block.

[0055] Here, the MCS may be determined using the CQI fed back from the UE 2. In the present disclosure, the MAC unit 2024 determines the MCS based on, for example, the CQI, the communication quality required for each service type, and the FH transmission quality information input from the FH quality calculation unit 204.

[0056] The FH quality calculation unit (or FH quality determination unit) 204 determines FH transmission quality information based on information on FH transmission quality measured as described below. The FH transmission quality information is an example of a signal quality index of the FH transmission section. As a non-limiting example, a signal-to-noise power (SN) ratio may be used for the FH transmission quality information.

[0057] The FH transmission quality information is input, for example, to the MAC unit 2024 in at least one master station signal processing unit 202#1. Additionally, the FH transmission quality information may also be input to the MAC unit 2024 in another master station signal processing unit 202#j (for example, j=2) different from the master station signal processing unit 202#1.

[0058] The MAC unit 2024 calculates the transmission quality of a propagation path that combines the FH propagation path and the wireless propagation path, for example, based on wireless quality information indicated by the CQI fed back from the UE 2 and FH transmission quality information. Then, the MAC unit 2024 determines the MCS so that the transmission quality when data is propagated through the combined propagation path satisfies the required quality according to the service type.

[0059] As a non-limiting example, the MAC unit 2024 combines the SNR of the wireless transmission section and the SNR of the FH transmission section. Based on the combined SNR, the MAC unit 2024 determines an MCS suitable for an integrated channel including the wireless transmission section and the FH transmission section.

[0060] Here, by allowing degradation of signal quality in FH transmission to the extent that signal interruption does not occur, it is possible to reduce the signal redundancy in FH transmission and reduce the traffic volume of FH transmission. For example, in order to reduce the traffic volume of FH transmission, it is permitted to select parameters for FH transmission that degrade signal quality.

[0061] In this case, in determining the MCS described above (in other words, controlling the wireless transmission method), an MCS that can compensate for the signal quality degradation permitted for FH transmission can be selected, thereby ensuring the transmission quality of the wireless communication system (hereinafter sometimes simply referred to as the "system").

[0062] Then, the MAC unit 2024 outputs control information, such as information on the determined MCS and information on resources (for example, resource elements (RE)) to be used for wireless transmission, to the subsequent High-PHY block 2001.

[0063] In the High-PHY block 2001, the encoding unit 2025, for example, adds a CRC (cyclic redundancy check) code to the transport block input from the MAC unit 2024 and divides the transport block into code blocks. The encoding unit 2025 also performs, for example, encoding of the code blocks and rate matching corresponding to the MCS.

[0064] The scrambling unit 2026 performs a scrambling process on the output of the encoding unit 2025, for example.

[0065] The modulation unit 2027 modulates the output of the scrambling unit 2026 using a modulation method such as QPSK (quadrature phase shift keying), 16QAM (quadrature amplitude modulation), 64QAM, or 256QAM.

[0066] The layer mapping unit 2028, for example, maps the output of the modulation unit 2027 into multiple layers.

[0067] The precoding unit 2029 performs precoding on the output of the layer mapping unit 2028, for example.

[0068] The RE mapping unit 2030 maps, for example, the output of the precoding unit 2029 to a predetermined radio resource (for example, RE). One RE is, for example, a radio resource area of ​​one subcarrier and one symbol. One or more REs may configure a resource block (RB). One or more RBs may be interchangeable with other terms such as a physical resource block (PRB), a subcarrier group (SCG), a resource element group (REG), a PRB pair, and an RB pair.

[0069] In addition, since the layer mapping unit 2028 and the precoding unit 2029 are used for MIMO (multiple-input and multiple-output) transmission, they may be omitted when MIMO transmission is not applied. In addition, control information for the UE to demodulate and decode a user data signal is multiplexed with the user data signal and transmitted from the radio base station 1 to the UE 2 (not shown). For example, the user data signal is transmitted on a PDSCH (physical downlink shared channel), and the control information is transmitted on a PDCCH (physical downlink control channel). The PDSCH and PDCCH are time-division multiplexed and wirelessly transmitted by different OFDM symbols.

[0070] Next, an example of the configuration of the master station signal processing unit 202#2 will be described. As illustrated in Fig. 2, the master station signal processing unit 202#2 includes an SDAP unit 2021 and a PDCP unit 2022. The functions of the SDAP unit 2021 and the PDCP unit 2022 may be the same as or similar to those in the master station signal processing unit 202#1.

[0071] In other words, the master station signal processing unit 202#2 does not include the RLC unit 2023, the MAC unit 2024, the encoding unit 2025, the scrambling unit 2026, the modulation unit 2027, the layer mapping unit 2028, the precoding unit 2029, and the RE mapping unit 2030. Functional units equivalent to these functional units 2023 to 2030 are arranged in the slave station processing device 50 (slave station signal processing unit 502#2), as described later with reference to FIG.

[0072] Therefore, the master station signal processing unit 202#2 has a different functional division configuration from the master station signal processing unit 202#1. In other words, the master station signal processing unit 202#1 and the master station signal processing unit 202#2 have different functional division points related to the base station functions, or the master station signal processing unit 202#1 and the master station signal processing unit 202#2 have different mappings of multiple functional units.

[0073] Next, in Fig. 2, a multiplexing unit 203 multiplexes the outputs of a plurality of different master station signal processing units 202#1 and 202#2. The multiplexed signal is output to an FH transmitter 30 having a configuration exemplified in Fig. 3. As a non-limiting example, the multiplexing method used in the multiplexing unit 203 may be time division multiplexing (TDM), frequency division multiplexing (FDM), code division multiplexing (CDM), or wavelength division multiplexing (WDM).

[0074] In the multiplexing unit 203, information for identifying the output signal of the master station signal processing unit 202#j (for example, signal ID#j) may be added. For example, a signal ID may be added to each output signal of the master station signal processing unit 202#j. Also, for example, time slot information in the case of TDM, frequency information in the case of FDM, and wavelength information in the case of WDM may each play the role of a signal ID.

[0075] Also, the multiplexing unit 203 may be omitted. For example, the outputs of the different master station signal processing units 202#1 and #2 may be input to the FH transmitter 30 in a physically separate manner.

[0076] The master station signal processing unit 202#1 and the master station signal processing unit 202#2 may be realized by physically different devices, or may be realized by being logically divided within the same device using, for example, a virtualization technology. A logically divided configuration may be called a "slice."

[0077] As described above, the number of master station signal processors 202#j may be two or more, and may be changed dynamically or adaptively in the case of logical division. For example, when the service type supported by the wireless base station 1 changes, a configuration suitable for the service type can be realized by increasing or decreasing the number of slices in response to the change.

[0078] For example, in the wireless base station 1, slices suitable for the type of service to be supported, such as slices for eMBB, URLLC, or mMTC, can be added or deleted as necessary. Therefore, a base station configuration suitable for the type of service can be flexibly realized.

[0079] Alternatively, the configuration of the master station signal processing unit 202#2 may be realized by omitting part of the processing of the master station signal processing unit 202#1 depending on the service type. In other words, the multiple master station signal processing units 202 may be realized by omitting or skipping part of the processing by multiple functional units constituting one master station signal processing unit 202. This point also applies to the other embodiments 2 to 4 described later.

[0080] In the master station device 11 having the configuration described above in FIG. 2, when attention is paid to the presence or absence of a MAC unit 2024, the master station signal processing unit 202#1 includes a MAC unit 2024, and the master station signal processing unit 202#2 does not include a MAC unit 2024.

[0081] FH transmission with a lower degree of redundancy than the master station signal processing unit 202#2 can be applied (or set) to the master station signal processing unit 202#1, which includes the MAC unit 2024. In contrast, FH transmission with a higher degree of redundancy, in other words, a more robust FH transmission, can be applied (or set) to the master station signal processing unit 202#2, which does not include the MAC unit 2024.

[0082] In this way, in the first embodiment, appropriate FH transmission according to the difference in the functional division configuration of the master station signal processing units 202#1 and 202#2 can be applied to the master station signal processing units 202#1 and 202#2 individually. In other words, according to the first embodiment, it is possible to optimize or correct FH transmission according to the service type #j. Therefore, for example, it is possible to avoid excessive redundancy being applied to a signal transmitted using FH13 in either of the master station signal processing units 202#1 and 202#2.

[0083] (FH transmitter 30) Next, an example of the configuration of FH transmitter 30 will be described with reference to Fig. 3. As shown in Fig. 3, FH transmitter 30 includes, for example, a demultiplexing unit 301, FH transmission processing units 302-1 and 302-2 corresponding to the service type, a multiplexing unit 303, a transmitting unit (Tx) 304, a receiving unit (Rx) 305, a measuring unit 306, and a control unit 307.

[0084] FH transmission processing units 302-1 and 302-2 may be written as FH transmission processing units 302#1 and 302#2, respectively. Furthermore, when there is no need to distinguish between FH transmission processing units 302-1 and 302-2, they may be written as FH transmission processing units 302. The number of FH transmission processing units 302 provided in FH transmitter 30 is not limited to two, and may be three or more. For example, N FH transmission processing units 302 corresponding to the number N of service types may be written as FH transmission processing units 302#j (j=1 to N).

[0085] FH transmission processing section 302#1 and FH transmission processing section 302#2 may be realized by physically different devices, or may be realized, for example, by being divided into software or hardware circuits within the same device.

[0086] The demultiplexer 301, for example, demultiplexes the signal received from FH13 into signals for different master station signal processors 202#j. When the signal received from FH13 is a multiplexed signal, the demultiplexer 301 identifies and demultiplexes the received signal for each master station signal processor 202#j based on, for example, the signal ID described above.

[0087] The receiving unit 305 receives a known signal (for example, a training signal) transmitted from the slave station device 12 (for example, an FH receiver 40 described later in FIG. 4) and propagated through FH 13, and outputs the signal to the measuring unit 306.

[0088] The measurement section 306 measures the reception quality of the known signal input from the reception section 305 and outputs the quality measurement result to, for example, the control section 307 .

[0089] Based on the quality measurement results by the measurement unit 306, the control unit 307 determines FH transmission parameters (e.g., one or more of the code type, coding rate, and modulation multi-level number) #j corresponding to each of the parent station signal processing units 202#j, and outputs them to the FH transmission processing units 302#1 and 302#2.

[0090] The control unit 307 may, for example, encode and modulate control information addressed to the slave station device 12 and output the encoded and modulated control information to the multiplexing unit 303. The control information may include, for example, the determined FH transmission parameters. Additionally or alternatively, the control information may include a quality measurement result by the measurement unit 306.

[0091] Each of the FH transmission processing units 302#1 and 302#2 includes, for example, an encoding unit 3021 and a modulation unit 3022.

[0092] The encoding unit 3021 performs encoding, for example, on the signal that is separated and output by the separation unit 301 and corresponds to the master station signal processing unit 202#j, in accordance with the FH transmission parameter #j from the control unit 307.

[0093] The modulation section 3022 modulates, for example, the output of the encoding section 3021 by a modulation method in accordance with the FH transmission parameter #j from the control section 307 (for example, any one of QPSK, 16QAM, 64QAM, and 256QAM).

[0094] The multiplexing unit 303 multiplexes, for example, signals from a plurality of different FH transmission processing units 302#j and control information from the control unit 307, and outputs the multiplexed signal to the transmission unit 304. As a non-limiting example, the multiplexing method used in the multiplexing unit 303 may be any one of TDM, FDM, CDM, and WDM.

[0095] In the multiplexing unit 303, information for identifying the output signal of the master station signal processing unit 202#j (for example, signal ID#j) may be added. For example, a signal ID may be added to each output signal of the master station signal processing unit 202#j. Also, for example, time slot information in the case of TDM, frequency information in the case of FDM, code information in the case of CDM, and wavelength information in the case of WDM may each play the role of a signal ID.

[0096] The transmitting unit 304 performs a transmission process on the output of the multiplexing unit 303 according to a wired transmission means (or a wired interface), such as a UTP cable, an STP cable, or an optical fiber cable, and transmits the processed signal to the FH 13.

[0097] The measurement section 306 of the FH transmitter 30 may include the function of the FH quality calculation section 204 (see FIG. 2) of the master station processing device 20. In that case, the master station processing device 20 does not need to be provided with the FH quality calculation section 204.

[0098] Furthermore, the FH quality calculation unit 204 of the master station processing device 20 and the control unit 307 of the FH transmitter 30 may be integrated into a single control unit. For example, the functions of one of the FH quality calculation unit 204 and the control unit 307 may be included in the other of the FH quality calculation unit 204 and the control unit 307. Furthermore, the measurement unit 306 of the FH transmitter 30 may be included in the control unit 307.

[0099] In other words, the functions of the FH quality calculation unit 204 , the measurement unit 306 , and the control unit 307 may be provided in the master station device 11 .

[0100] Furthermore, the FH transmitter 30 may be realized in the same device 20 as the master station processing device 20. In this case, for example, the multiplexing unit 203 and the demultiplexing unit 301 may not be necessary. For example, signals from different master station signal processing units 202#j corresponding to different service types may be processed in parallel within one device 20.

[0101] <Slave station device 12> Next, an example of the configuration of the slave station device 12 will be described.

[0102] (FH receiver 40) FIG. 4 is a block diagram showing an example of the configuration of FH receiver 40. As shown in FIG. As illustrated in FIG. 4, the FH receiver 40 includes, for example, a receiving unit 401, a separating unit 402, FH reception processing units 403-1, 403-2 corresponding to parent station signal processing units 202#1 and #2 (in other words, multiple service types #1 and #2), a multiplexing unit 404, a control unit 405, a training data unit 406, and a transmitting unit 407.

[0103] FH reception processing units 403-1 and 403-2 may be written as FH reception processing units 403#1 and 403#2, respectively. Furthermore, when there is no need to distinguish between FH reception processing units 403-1 and 403-2, they may be written as FH reception processing unit 403. The number of FH reception processing units 403 provided in FH receiver 40 is not limited to two, and may be three or more. For example, N FH reception processing units 403 corresponding to the number N of service types may be written as FH reception processing units 403#j (j = 1 to N).

[0104] The FH reception processing section 403#1 and the FH reception processing section 403#2 may be realized by physically different devices, or may be realized, for example, by being divided into software or hardware circuits within the same device.

[0105] The receiving unit 401 performs reception processing on a signal received from the FH 13 according to a wired transmission means (or a wired interface) such as a UTP cable, an STP cable, or an optical fiber cable, and outputs the processed signal to the separating unit 402 .

[0106] The separator 402 separates signals corresponding to different master station signal processors 202#j from the output of the receiver 401, for example, based on the signal ID described above, and outputs the separated signals to the FH reception processor 403#j. The separator 402 also separates control information multiplexed in the FH transmitter 30 from the output of the receiver 401, for example, and outputs the separated signals to the controller 405.

[0107] The control unit 405 decodes the control information input from the demultiplexing unit 402 (for example, FH transmission parameters #j corresponding to each master station signal processing unit 202#j), and outputs the decoded information to the FH reception processing unit 403#j.

[0108] Each of the FH reception processing units 403 #j includes a demodulation unit 4031 and a decoding unit 4032 .

[0109] Demodulation section 4031 demodulates the output of separation section 402, for example, in accordance with control information (for example, FH transmission parameter #j) from control section 405.

[0110] The decoding unit 4032 decodes the output of the demodulation unit 4031, for example, in accordance with control information (for example, FH transmission parameter #j) from the control unit 405.

[0111] The multiplexing unit 404, for example, multiplexes the outputs of a plurality of different FH reception processing units 403#j and outputs the multiplexed signals to the slave station processing device 50. The signals multiplexed in the multiplexing unit 404 may be considered to correspond to signals addressed to a plurality of different slave station signal processing units in the slave station processing device 50 (for example, slave station signal processing units 502#1 and 502#2 described later in FIG. 5).

[0112] As a non-limiting example, TDM, FDM, CDM, or WDM may be applied as the multiplexing method in the multiplexing unit 404. In the multiplexing unit 404, information for identifying the output signal of the FH reception processing unit 403#j (e.g., signal ID#j) may be added. For example, a signal ID may be added to each output signal of the FH reception processing unit 403#j. Also, for example, time slot information in the case of TDM, frequency information in the case of FDM, and wavelength information in the case of WDM may each play the role of a signal ID.

[0113] Also, the multiplexing unit 404 may be omitted. For example, the outputs of the different FH reception processing units 403#1 and 403#2 may be input to the local station processor 50 in a physically separate manner.

[0114] The training data unit 406 generates a known signal for measuring the transmission quality of FH13, for example, and outputs the signal to the transmitting unit 407. The "known signal" is, for example, a training signal (or data) that is used by specifying a predetermined sequence between a transmitter and a receiver in advance. The training signal may be called by other names such as a pilot signal or a reference signal.

[0115] The transmitting unit 407 transmits, for example, a training signal to the FH 13 connected to the master station device 11 (for example, the FH transmitter 30). The training signal transmitted to the FH 13 is received, for example, by the receiving unit 305 of the FH transmitter 30 in the master station device 11 (see FIG. 3).

[0116] In addition, measurement of FH13 transmission quality using a known signal may be performed by transmitting the known signal from FH transmitter 30 to FH receiver 40, measuring the FH13 transmission quality in FH receiver 40, and feeding back the measurement results to FH transmitter 30.

[0117] It should be noted that the control section 405 , the training data section 406 , and some or all of the transmission section 407 do not have to be provided inside the FH receiver 40 , and may be provided inside the slave station device 12 .

[0118] (slave station processing device 50) Next, an example of the configuration of the slave station processing device 50 will be described with reference to FIG. As illustrated in FIG. 5, the slave station processing device 50 includes, for example, a separation unit 501, slave station signal processing units 502-1 and 502-2, a D / A (digital to analog) conversion unit 503, and an RF (radio frequency) unit 504.

[0119] The child station signal processing units 502-1 and 502-2 may be written as child station signal processing units 502#1 and 502#2, respectively. When the child station signal processing units 502-1 and 502-2 are not to be distinguished from each other, they may be written as child station signal processing units 502. The number of child station signal processing units 502 provided in the child station processing device 50 is not limited to two, and may be three or more. For example, N child station signal processing units 502 corresponding to the number N of service types may be written as child station signal processing units 502#j (j=1 to N).

[0120] The child station signal processing unit 502#1 and the child station signal processing unit 502#2 may be realized by physically different devices, or may be realized by being divided into logical slices, for example.

[0121] The demultiplexer 501 demultiplexes signals addressed to different slave station signal processors 502#j based on, for example, the above-mentioned signal ID, and outputs the demultiplexed signals to the corresponding slave station signal processors 502#j.

[0122] The slave station signal processing units 502-1 and 502-2 have different functional division configurations because the master station signal processing units 202-1 and 202-2 have different functional division configurations (in other words, different functional division points) as described in FIG.

[0123] For example, the slave station signal processing unit 502-1 includes a beamforming unit 5029 and an IFFT+cyclic prefix (CP) unit 5030 due to the functional division point in the master station signal processing unit 202-1 corresponding to the service type #1.

[0124] In contrast, the child station signal processing unit 502-2 is provided with, for example, an RLC unit 5021, a MAC unit 5022, an encoding unit 5023, a scrambling unit 5024, a modulation unit 5025, a layer mapping unit 5026, a precoding unit 5027, an RE mapping unit 5028, a beamforming unit 5029, and an IFFT+CP unit 5030, depending on the functional division point in the parent station signal processing unit 202-2 corresponding to service type #2.

[0125] In the child station signal processing unit 502-1, the beamforming unit 5029 and the IFFT+CP unit 5030 form a lower physical layer (Low-PHY) block 5002, for example.

[0126] The beam forming unit 5029 of the child station signal processing unit 502-1 performs beam forming processing on the output of the demultiplexing unit 501, for example.

[0127] The IFFT+CP unit 5030 of the child station signal processing unit 502-1 performs IFFT and CP insertion on the output of the beamforming unit 5029, for example.

[0128] On the other hand, in the slave station signal processing unit 502-2, the functional units 5021 to 5028 form, for example, a High-PHY block 5001. Also, in the slave station signal processing unit 502-2, the beamforming unit 5029 and the IFFT+CP unit 5030 form a Low-PHY block 5002, for example.

[0129] The functional units 5021 to 5028 of the slave station signal processing unit 502-2 may be considered to be similar to the functional units 2023 to 2030 (see FIG. 2) of the master station signal processing unit 202-1, respectively.

[0130] The beamforming unit 5029 of the child station signal processing unit 502-2 performs beamforming processing on the output of the RE mapping unit 5028, for example.

[0131] The IFFT+CP unit 5030 of the child station signal processing unit 502-2 performs IFFT and CP insertion on the output of the beamforming unit 5029 of the child station signal processing unit 502-2, for example.

[0132] The D / A conversion unit 503 converts, for example, each output of the child station signal processing units 502#1 and 502#2 (outputs of the two IFFT+CP units 5030) from a digital signal to an analog signal.

[0133] The RF unit 504 performs transmission RF processing, such as up-conversion to a radio frequency and amplification, on the output of the D / A conversion unit 503. A radio signal generated by the transmission RF processing is radiated into space (for example, transmitted to UE 2) via an antenna (not shown) provided in the RF unit 504.

[0134] The Low-PHY block 5002 may be separate for the child station signal processors 502#1 and 502#2 or may be shared. In the case of sharing, the processes of the different child station signal processors 502 may be executed in parallel in one Low-PHY block 5002.

[0135] 4 may be implemented in the same device 50 as the slave station processing device 50. In this case, for example, the multiplexer 404 and the separator 501 may not be provided. For example, signals from different slave station signal processors 502#j corresponding to service type #j may be processed in parallel within one device.

[0136] In addition, the child station signal processing unit 502#1 and the child station signal processing unit 502#2 may be realized by physically different devices, or may be realized by being logically divided within the same device using, for example, virtualization technology.

[0137] The number of the child station signal processing units 502#j may be two or more, and may be changed dynamically or adaptively in the case of logical division. For example, as described above, when the service type supported by the wireless base station 1 changes, the number of slices #j corresponding to the child station signal processing units 502#j may be increased or decreased according to an increase or decrease in the number of slices #j corresponding to the parent station signal processing units 202#j.

[0138] Furthermore, one or both of the D / A conversion unit 503 and the RF unit 504 illustrated in FIG. 5 may be provided individually for the different slave station signal processing units 502#j.

[0139] At least one of the master station processing device 20 and the slave station processing device 50 may be configured by a logical slice. At least one of the master station processing device 11 and the slave station processing device 12 may be configured by a logical slice.

[0140] Also, depending on the service type, the configuration of the child station signal processing unit 502#2 may be realized by omitting part of the processing of the child station signal processing unit 502#1. In other words, the multiple child station signal processing units 502 may be realized by omitting or skipping part of the processing by multiple functional units constituting one child station signal processing unit 502. This point also applies to the other embodiments 2 to 4 described later.

[0141] (Example of operation) Next, an example of the operation of the wireless communication system according to the first embodiment will be described with reference to a sequence diagram of FIG.

[0142] As shown in Fig. 6, in the wireless base station 1, a known signal is transmitted from the transmitter 407 (see Fig. 4) of the FH receiver 40 in the slave station device 12 to the FH transmitter 30 (S601). The known signal may be transmitted, for example, when the wireless communication system is started up or at a predetermined timing after the start-up. For example, the predetermined timing may be set to a time period when the traffic volume of FH13 is relatively low (for example, early morning or late night) in order to reduce congestion of the FH band.

[0143] The known signal is received, for example, by the receiving section 305 (see FIG. 3) of the FH transmitter 30, and input to the measuring section 306. The measuring section 306 measures the reception quality of the input known signal (S602).

[0144] Information indicating the measurement results (measurement information) is input, for example, to the control unit 307 of the FH transmitter 30 (see FIG. 3) and the FH quality calculation unit 204 of the master station processing device 20 (see FIG. 2) (S603a and S603b).

[0145] In the master station processing device 20, the FH quality calculation section 204 determines FH transmission quality information based on the input measurement information, and outputs it to, for example, the MAC section 2024 of the master station signal processing section 202#1.

[0146] The MAC unit 2024 calculates and determines the transmission quality of the propagation path that combines the wireless propagation path and the FH propagation path, for example, based on the CQI (not shown) fed back from the UE, the communication quality required for each service type, and the FH transmission quality information (S604).

[0147] Then, the MAC unit 2024 determines, for example, the MCS for the wireless transmission section to be an MCS that satisfies the required quality according to the service type when the signal quality when data is propagated through the integrated propagation path.

[0148] As a non-limiting example, the MAC unit 2024 combines the SNR of the wireless transmission section and the SNR of the FH transmission section, and determines an MCS suitable for the integrated propagation path including the wireless transmission section and the FH transmission section based on the combined SNR (S606).

[0149] Meanwhile, in FH transmitter 30, control unit 307 to which the measurement information has been input determines the transmission method for FH transmission, in other words, the FH transmission parameters to be used for FH transmission (for example, one or more of the code type, coding rate, and modulation multi-level number) based on the measurement information (S605). Note that the determination processes of S605 and S606 may be performed at the same timing, or may be performed at different (or shifted) timings.

[0150] The master station signal processing unit 202#1 encodes and modulates a DL signal of service type #1 (e.g., user data processed by the SDAP unit 2021 and PDCP unit 2022) in accordance with the MCS determined in S606, and outputs the signal to the FH transmitter 30 (S607). In response to this, the master station signal processing unit 202#2 outputs a DL signal corresponding to service type #2 (e.g., user data processed by the SDAP unit 2021 and PDCP unit 2022) to the FH transmitter 30 (S607).

[0151] In the FH transmitter 30, user data (hereinafter also referred to as "DL data") corresponding to each of the service types #1 and #2 is coded and modulated in the corresponding FH transmission processing units 302#1 and 302#2 according to the FH transmission parameters determined in S605, and then transmitted to the FH 13 (S608).

[0152] The DL data transmitted to the FH 13 from the master station device 11 is received by the receiving section 401 of the FH receiver 40 in the slave station device 12, and is demodulated and decoded by the FH reception processing section 403 according to the service types #1 and #2.

[0153] The DL data demodulated and decoded in the FH receiver 40 is transmitted to the slave station processing device 50 (S609). In the slave station processing device 50, the DL data received from the FH receiver 40 is processed in slave station signal processing units 502#1 and 502#2 according to service types #1 and #2.

[0154] For example, the local station signal processor 502#1 performs beamforming processing and IFFT(+CP) processing on the received DL data corresponding to the service type #1. The DL data that has been subjected to each processing is transmitted to the UE2 from the antenna as a wireless signal (S610).

[0155] On the other hand, the slave station signal processor 502#2 performs each process of RLC, MAC, encoding, scrambling, modulation, layer mapping, precoding, RE mapping, beamforming, and IFFT(+CP) on DL data corresponding to the service type #2. The DL data that has been subjected to each process is transmitted to UE2 from the antenna as a wireless signal (S610).

[0156] According to the first embodiment, the functional division configuration of the master station device 11 and the slave station device 12 differs depending on the service type, so that the traffic volume of FH13 can be efficiently reduced. Also, the transmission method of FH transmission can be properly used depending on the difference in the functional division configuration of the master station device 11 and the slave station device 12 (in other words, the FH transmission method can be optimized for each service type). Therefore, for example, the data redundancy in FH transmission can be reduced, and the traffic volume of FH13 can be reduced.

[0157] Furthermore, when low-redundancy (lower signal quality) FH transmission parameters are permitted to be selected in order to control the traffic volume of FH transmission, the permitted degradation in signal quality can be compensated for by controlling the wireless transmission method (e.g., wireless transmission parameters such as MCS), thereby ensuring the transmission quality of the wireless communication system.

[0158] (Embodiment 2) Next, a description will be given of embodiment 2. Fig. 7 is a block diagram showing an example of the configuration of a master station processing device 20 provided in a master station device 11 according to embodiment 2. Fig. 8 is a block diagram showing an example of the configuration of an FH transmitter 30 provided in a master station device 11 according to embodiment 2.

[0159] An example of the configuration of the FH receiver 40 and the slave station processing device 50 in the slave station device 12 according to the second embodiment may be the same as or similar to the configurations illustrated in FIG. 4 and FIG. 5 in the first embodiment, respectively.

[0160] The master station processing device 20 illustrated in FIG. 7 differs from the master station processing device 20 illustrated in FIG. 2 in that it includes a target quality set unit 205 instead of the FH quality calculation unit 204.

[0161] 3, the FH transmitter 30 illustrated in Fig. 8 differs in that the output of the target quality setting section 205 (for example, setting information (or request information) related to the target quality) is input to the control section 307. The setting information (or request information) related to the target quality may be referred to as "target quality information" for convenience.

[0162] Hereinafter, the second embodiment will be described with a focus on the above-mentioned differences (or differences).

[0163] 7 generates, for example, target quality information for FH 13. The target quality information may be specified in advance as information indicating a quality to be set or requested in FH 13 according to a quality requirement for each service type, or may be notified from the core network 11. stomach.

[0164] The target quality information is transmitted, for example, to the MAC unit 2024 in at least one master station signal processing unit 202#1 illustrated in Fig. 7 and to the FH transmitter 30 illustrated in Fig. 8. The target quality information transmitted to the FH transmitter 30 may be multiplexed in the multiplexing unit 203 with DL data transmitted to the FH transmitter 30, or may not be multiplexed with DL data transmitted to the FH transmitter 30. When the target quality information is not multiplexed with DL data, the target quality information may be transmitted to the FH transmitter 30 by bypassing the multiplexing unit 203.

[0165] The MAC unit 2024 to which the target quality information has been input determines the MCS to be applied to DL data of service type #1, for example, based on the CQI and the target quality information.

[0166] 8, the target quality information is received by the control unit 307. When the target quality information is multiplexed with DL data, the target quality information is separated by the separation unit 301 and input to the control unit 307. When the target quality information is not multiplexed with DL data, the target quality information is input to the control unit 307 without passing through the separation unit 301.

[0167] 8 determines FH transmission parameters (e.g., one or more of the code type, coding rate, and modulation multi-level number) #j corresponding to each master station signal processor 202#j based on, for example, target quality information and measurement information related to the FH13 transmission quality by the measurement unit 306. The determined FH transmission parameters #j are output to the corresponding FH transmission processors 302#1 and 302#2.

[0168] The control unit 307 may, for example, encode and modulate control information addressed to the slave station device 12 and output the encoded and modulated control information to the multiplexing unit 303. The control information may include, for example, the determined FH transmission parameters. Additionally or alternatively, at least one of the target quality information and the quality measurement result by the measurement unit 306 may be included in the control information.

[0169] The FH transmission processing unit 302(#j) performs coding and modulation of DL data in the coding unit 3021 and the modulation unit 3022, respectively, according to the FH transmission parameter #j determined based on the target quality information, for example. As a result, coding and modulation suitable for FH transmission are performed on the DL data for each service type #j.

[0170] In other words, based on the target quality information, the FH transmission quality for each service type #j is controlled in the FH transmitter 30. Therefore, the target quality information may be regarded as an example of control information for controlling the transmission quality of FH13.

[0171] (Example of operation) Next, an example of the operation of the wireless communication system according to the second embodiment will be described with reference to a sequence diagram of FIG.

[0172] As illustrated in FIG. 9, in the master station processing device 20 of the master station device 11, the target quality setting unit 205 determines target quality information (S901).

[0173] The determined target quality information is transmitted to the MAC section 2024 illustrated in FIG. 7 and to the control section 307 in the FH transmitter 30 illustrated in FIG. 8 (S902a and S902b).

[0174] The FH transmitter 30 also receives a known signal that has been transmitted from the FH receiver 40 in the slave station device 12 to FH 13 and propagated through FH 13 (S903). The FH transmitter 30 measures the reception quality of the known signal that has propagated through FH 13, and outputs the measurement result to the control unit 307 (S904a).

[0175] The control unit 307 determines FH transmission parameters #j corresponding to each master station signal processing unit 202#j (S905) based on the target quality information received in S902b and the measurement results by the measurement unit 306. The determined FH transmission parameters #j are input to the corresponding FH transmission processing unit 302#j.

[0176] On the other hand, in the master station processing device 20, the MAC unit 2024 of the master station signal processing unit 202#1 determines the transmission quality of the propagation path that integrates the wireless propagation path and the FH propagation path, for example, based on the CQI fed back from the UE 2 and the target quality information input in S902a. Then, the MAC unit 2024 determines, for example, the MCS of the wireless transmission section to be an MCS that satisfies the required quality according to the service type when the signal quality when data is propagated through the integrated propagation path (S906).

[0177] The timing of receiving the known signal (S903) and the timing of measurement (S904) in the FH transmitter 30 may be later than the timing of receiving the target quality information (S902b) or earlier than the timing of receiving the target quality information (S902b).

[0178] Furthermore, the determination processes of S905 and S906 may be executed at the same timing, or may be executed at different (or shifted) timings.

[0179] The master station signal processing unit 202#1 encodes and modulates a DL signal of service type #1 (e.g., user data processed by the SDAP unit 2021 and PDCP unit 2022) in accordance with the MCS determined in S906, and outputs the signal to the FH transmitter 30 (S907). In response to this, the master station signal processing unit 202#2 outputs a DL signal corresponding to service type #2 (e.g., user data processed by the SDAP unit 2021 and PDCP unit 2022) to the FH transmitter 30 (S907).

[0180] In the FH transmitter 30, user data (hereinafter also referred to as "DL data") corresponding to each of the service types #1 and #2 is coded and modulated in the corresponding FH transmission processing units 302 #1 and #2 according to the FH transmission parameters determined in S905, and then transmitted to the FH 13 (S908).

[0181] The subsequent DL data transmission processes S909 and S910 by the slave station device 12 (the FH receiver 40 and the slave station processing device 50) may be equivalent to the processes S609 and S610 described with reference to FIG. 6 in the first embodiment, respectively.

[0182] As described above, according to the second embodiment, in addition to obtaining the same operational effects as those of the first embodiment, it is possible to eliminate the need for feedback of the measurement results on the FH transmission quality from the FH transmitter 30 to the master station processing device 20, as described in the first embodiment. Therefore, it is possible to improve the utilization efficiency of the FH band.

[0183] In addition, feedback of measurement results related to FH transmission quality may be used in combination in the second embodiment. By implementing this feedback, for example, it is possible for the master station processor 20 to compensate for deviations or fluctuations in the FH transmission quality from a target quality.

[0184] Furthermore, the target quality setting unit 205 of the master station processing device 20 and the control unit 307 of the FH transmitter 30 may be integrated into a single control unit. For example, the functions of one of the target quality setting unit 205 and the control unit 307 may be included in the other of the target quality setting unit 205 and the control unit 307. Furthermore, the measurement unit 306 of the FH transmitter 30 may be included in the control unit 307.

[0185] In other words, in the second embodiment, the functions of the target quality setting unit 205, the measurement unit 306, and the control unit 307 may be provided in the master station device 11.

[0186] (Embodiment 3) Next, a description will be given of embodiment 3. In embodiment 3, for example, a CRC result of DL data or acknowledgement (Ack / Nack) information based on the CRC result is used to measure FH transmission quality instead of a known signal such as a training signal.

[0187] Fig. 10 is a block diagram showing an example of the configuration of an FH receiver 40 provided in a slave station device 12 according to embodiment 3. The FH receiver 40 shown in Fig. 10 differs from the configuration shown in Fig. 4 in that it includes an Ack / Nack calculation unit 408 instead of the training data unit 406.

[0188] In the third embodiment, the configuration of the master station device 11 (master station processing device 20 and FH transmitter 30) may be the same as or similar to the configurations illustrated in Figures 2 and 3 of the first embodiment. In the third embodiment, the configuration of the slave station processing device 50 provided in the slave station device 12 may be the same as or similar to the configuration illustrated in Figure 5 of the first embodiment.

[0189] Hereinafter, the third embodiment will be described with a focus on the differences (or differences) from the first embodiment.

[0190] 10 receives information (Ack / Nack information) indicating an acknowledgment (Ack) or a negative acknowledgment (Nack) from each of the decoders 4032 of the slave station signal processors 502#1 and 502#2. The Ack / Nack information is generated based on a determination of a CRC result in each of the decoders 4032 of the slave station signal processors 502#1 and 502#2, for example.

[0191] The Ack / Nack calculation unit 408 calculates, for example, statistics of Ack / Nack information (for example, at least one of an Ack rate and a Nack rate) over a specific period of time. The Ack / Nack statistical information that is the calculation result is transmitted (feedback) from the transmission unit 407 to the FH transmitter 30 of the master station device 11, for example.

[0192] In addition, the Ack / Nack statistical information indicates that, for example, a higher Ack rate (or a lower Nack rate) indicates higher FH transmission quality, and a higher Nack rate (or a lower Ack rate) indicates lower FH transmission quality. Therefore, the Ack / Nack statistical information may be regarded as an example of FH transmission quality information.

[0193] The Ack / Nack statistical information fed back to the master station 11 is received, for example, by the receiver 305 of the FH transmitter 30 illustrated in FIG.

[0194] The measurement unit 306 judges or determines the transmission quality of FH13 based on the Ack / Nack statistical information. The judgment or determination of the transmission quality of FH13 may be performed in the Ack / Nack calculation unit 408. In this case, instead of the Ack / Nack statistical information, the result of the judgment or determination of the FH transmission quality may be transmitted (feedback) from the transmission unit 407 to the FH transmitter 30 of the master station device 11 as an example of FH transmission quality information.

[0195] (Example of operation) Next, an example of the operation of the wireless communication system according to the third embodiment will be described with reference to a sequence diagram of FIG.

[0196] 11, at a certain timing, the parent station processing device 20 of the wireless base station 1 transmits, for example, user data (DL data) received from an upper core network to the FH transmitter 30 (S1101). The FH transmitter 30 transmits the received DL data to the child station device 12 via the FH 13 (S1102).

[0197] In the slave station device 12, the DL data propagated through FH 13 is received by the FH receiver 40. In the FH receiver 40, the DL data is separated by the separation unit 402 according to the service type #j, and decoded by the corresponding decoding unit 4032.

[0198] At this time, the decoder 4032 performs a CRC check on the DL data (S1103) and generates Ack / Nack information based on the CRC check result. The decoded DL data is transmitted from the FH receiver 40 to the slave station processor 50 (S1104), and the slave station processor 50 transmits the received DL data to the UE2 by wireless signal (S1105).

[0199] The Ack / Nack information generated in the decoding unit 4032 is input to the Ack / Nack calculation unit 408. The Ack / Nack calculation unit 408 calculates statistics of the input Ack / Nack information (S1106).

[0200] Note that DL data transmission from the FH receiver 40 to the slave station processor 50 may be performed after the calculation of the statistics of the Ack / Nack information (S1106). Also, the Ack / Nack statistical information may be updated by sequentially repeating the CRC determination of the DL data (S1103) and the Ack / Nack statistical calculation (S1106).

[0201] The Ack / Nack statistical information obtained by the Ack / Nack calculation unit 408 is transmitted (feedback) from the transmission unit 407 of the FH receiver 40 to the master station device 11 via the FH 13 (S1107).

[0202] The Ack / Nack statistical information fed back to the master station 11 is received by a receiver 305 (see FIG. 3, for example) of the FH transmitter 30. The Ack / Nack statistical information received by the receiver 305 is input to a measurement section 306.

[0203] The measurement unit 306 judges or determines the FH transmission quality based on the Ack / Nack statistical information, and outputs the result (FH transmission quality information) to the control unit 307 of the FH transmitter 30. In addition, the FH transmission quality information is transmitted from the measurement unit 306 to the master station processing device 20 (S1108).

[0204] The control unit 307 determines the transmission method for FH transmission, in other words, the transmission parameters to be used for FH transmission (for example, one or more of the code type, coding rate, and modulation multi-level number) based on the FH transmission quality information (S1109).

[0205] In the master station processing device 20, the MAC unit 2024 of the master station signal processing unit 202#1 determines the transmission quality of the propagation path that integrates the wireless propagation path and the FH propagation path, for example, based on the CQI fed back from the UE 2, the required quality for each service type, and the FH transmission quality information. Then, the MAC unit 2024 determines the MCS of the wireless transmission section to be, for example, an MCS that satisfies the required quality according to the service type when the signal quality when data is propagated through the integrated propagation path (S1110).

[0206] The determination processes of S1109 and S1110 may be executed at the same timing, or may be executed at different (or shifted) timings.

[0207] The master station signal processing unit 202#1 encodes and modulates a DL signal of service type #1 (e.g., DL data processed by the SDAP unit 2021 and PDCP unit 2022) in accordance with the MCS determined in S1110, and outputs the signal to the FH transmitter 30 (S1111). In response to this, the master station signal processing unit 202#2 outputs a DL signal corresponding to service type #2 (e.g., DL data processed by the SDAP unit 2021 and PDCP unit 2022) to the FH transmitter 30 (S1111).

[0208] In the FH transmitter 30, the DL data corresponding to each of the service types #1 and #2 is coded and modulated in the corresponding FH transmission processing units 302#1 and 302#2 according to the FH transmission parameters determined in S1109, and then transmitted to the FH 13 (S1112).

[0209] The subsequent DL data transmission processes S1113 and S1114 by the slave station device 12 (the FH receiver 40 and the slave station processing device 50) may be equivalent to the processes S609 and S610 described with reference to FIG. 6 in the first embodiment, respectively.

[0210] As described above, according to the third embodiment, in addition to obtaining the same operational effects as those of the first embodiment, it is possible to eliminate the need for transmission and reception of a known signal for measuring the FH transmission quality as in the first embodiment, thereby improving the utilization efficiency of the FH band.

[0211] In the third embodiment, the FH transmission quality measurement using a known signal in the first embodiment may be used in combination. For example, the FH transmission quality measurement using a known signal may be performed in advance, and fluctuations that may occur in the measurement result may be corrected using Ack / Nack statistical information. Furthermore, the Ack / Nack statistical information may be notified to the master station device 20, and the master station device 20 may correct and update the wireless transmission method based on the Ack / Nack statistical information.

[0212] Here, performing FH transmission quality measurement in advance may mean performing FH transmission quality measurement at a timing prior to CRC determination (see S1103 in FIG. 11), such as at system startup, for example.

[0213] The function of the Ack / Nack calculation unit 408 of the FH receiver 40 may be included in the control unit 405. The Ack / Nack calculation unit 408 may be provided outside the FH receiver 40, or may be provided in the slave station device 12.

[0214] (Embodiment 4) Next, a description will be given of embodiment 4. In embodiment 4, an example of a configuration focusing on the UL of the wireless base station 1 in embodiment 1 will be described with reference to Figs.

[0215] Fig. 12 is a diagram showing an example of the configuration of a wireless communication system according to embodiment 4. In the wireless base station 1 shown in Fig. 1, the slave station device 12 includes a slave station processing device 60 and an FH transmitter 70, and the master station device 11 includes an FH receiver 80 and a master station processing device 90.

[0216] As in the first to third embodiments, the number of radio base stations 1 and the number of UEs 2 may each be equal to or greater than 2. In the master station device 11, the master station processing device 20 for DL ​​and the master station processing device 90 for UL may be configured as physically different devices, or may be realized in the same physical device.

[0217] Similarly, the DL FH transmitter 30 and the UL FH receiver 80 may be configured as physically different devices, or may be implemented in the same physical device. Also, the FH transmitter 30 and the FH receiver 80 may be integrated, for example, as an FH transmission / reception device or an FH communication device shared by both the DL and the UL.

[0218] Similarly, in the slave station device 12, the DL FH receiver 40 and the UL FH transmitter 70 may be configured as physically different devices, or may be realized in the same physical device. Also, the FH receiver 40 and the FH transmitter 70 may be integrated, for example, as an FH transmission / reception device or an FH communication device shared by DL and UL.

[0219] Furthermore, the DL child station processing device 50 and the UL child station processing device 60 may be configured as physically different devices, or may be realized within the same physical device.

[0220] In the master station device 11, at least one of the DL master station processing device 20 and the UL master station processing device 90 may be configured by a logical slice.

[0221] Similarly, in the slave station equipment 12, at least one of the DL slave station processing device 50 and the UL slave station processing device 60 may be configured by a logical slice.

[0222] At least one of the master station device 11 and the slave station device 12 may be configured by a logical slice.

[0223] <Slave station device 12> FIG. 13 is a block diagram showing an example of the configuration of a slave station processing device 60 provided in the slave station equipment 12, and FIG. 14 is a block diagram showing an example of the configuration of an FH transmitter 70 provided in the slave station equipment 12.

[0224] (slave station processing device 60) As illustrated in FIG. 13, the slave station processing device 60 includes, for example, an RF unit 601, an A / D (analog to digital) conversion unit 602, slave station signal processing units 603-1 and 603-2, and a multiplexing unit 604.

[0225] The child station signal processing units 603-1 and 603-2 may be written as child station signal processing units 603#1 and 603#2, respectively. When there is no need to distinguish between the child station signal processing units 603-1 and 603-2, they may be written as child station signal processing units 603. The number of child station signal processing units 603 provided in the child station processing device 60 is not limited to two, and may be three or more. For example, N child station signal processing units 603 corresponding to the number N of service types may be written as child station signal processing units 603#j (j=1 to N).

[0226] The child station signal processing unit 603#1 and the child station signal processing unit 603#2 may be realized by physically different devices, or may be realized by being divided into logical slices, for example.

[0227] The RF unit 601, for example, has an antenna, receives an UL radio signal transmitted from the UE 2 via the antenna, and performs RF reception processing such as down-conversion processing and low-noise amplification processing on the received radio signal.

[0228] The A / D conversion unit 602 converts, for example, the output (analog signal) of the RF unit 601 into a digital signal.

[0229] The slave station signal processing units 603-1 and 603-2 have different functional division configurations. For example, the slave station signal processing unit 603-1 includes a CP removal+FFT unit 6031 and a beamforming unit 6032 due to the functional division point in the master station signal processing unit 902-1 (see FIG. 16) corresponding to the service type #1.

[0230] In contrast, the child station signal processing unit 603-2 is equipped with, for example, a CP removal+FFT unit 6031, a beamforming unit 6032, an RE (resource element) demapping unit 6033, a layer demapping unit 6034, a demodulation unit 6035, a descrambling unit 6036, a decoding unit 6037, a MAC unit 6038, and an RLC unit 6039, due to the functional division point in the parent station signal processing unit 902-2 corresponding to service type #2.

[0231] In the child station signal processing unit 603-1, the CP removal+FFT unit 6031 and the beamforming unit 6032 form a lower physical layer (Low-PHY) block 6002, for example.

[0232] The CP removal+FFT unit 6031 of the child station signal processing unit 603-1 performs FFT and CP removal on the output of the A / D conversion unit 602, for example.

[0233] The beam forming unit 6032 of the slave station signal processing unit 603-1 performs, for example, a process of forming a receiving beam on the output of the CP removal+FFT unit 6031.

[0234] On the other hand, in the slave station signal processing unit 603-2, the functional units 6031 to 6039 form, for example, a High-PHY block 6001. In addition, in the slave station signal processing unit 603-2, the FFT+CP unit 6031 and the beamforming unit 6032 form a Low-PHY block 6002, for example.

[0235] The Low-PHY block 6002 may be separate for the child station signal processing units 603-1 and 603-2 or may be shared. In the case of sharing, the processes of the different child station signal processing units 603 may be executed in parallel in one Low-PHY block 6002. Also, control information related to UE transmission for demodulating and decoding a user data signal in the radio base station is transmitted from the radio base station 1 to the UE 2 (not shown). For example, the radio base station 1 notifies the UE 2 of the control information by a PDCCH. The UE 2 transmits a user data signal to the radio base station 1 by a physical uplink shared channel (PUSCH) based on the control information received by the PDCCH.

[0236] In the child station signal processing unit 603-2, the CP removal+FFT unit 6031 performs FFT and CP removal on the output of the A / D conversion unit 602, for example, and the beam forming unit 6032 performs reception beam formation processing on the output of the CP removal+FFT unit 6031, for example.

[0237] Furthermore, in the child station signal processing unit 603-2, the RE demapping unit 6033 demaps the UL signal mapped to radio resources (for example, REs).

[0238] The layer demapping unit 6034, for example, demaps the UL signal mapped for each layer at the output of the RE demapping unit 6033. Note that since the layer demapping unit 6034 is used for MIMO transmission, it may be omitted when MIMO transmission is not applied.

[0239] The demodulation unit 6035 demodulates the output of the layer demapping unit 6034, for example, by a demodulation method corresponding to a modulation method such as QPSK, 16QAM, 64QAM, or 256QAM.

[0240] The descrambling unit 6036 performs a descrambling process on the output of the demodulation unit 6035, for example, to remove the scrambling.

[0241] The decoding unit 6037 decodes, for example, the output of the descrambling unit 6036 .

[0242] The MAC unit 6038 generates an RLC PDU from the MAC PDU of the UL signal, for example, and outputs the RLC PDU to the RLC unit 6039 .

[0243] The multiplexing unit 604, for example, multiplexes the outputs of the different slave station signal processing units 603-1 and 603-2, and transmits the multiplexed signal to the FH transmitter 70 (see FIG. 14). As a non-limiting example, the multiplexing method used by the multiplexing unit 604 may be TDM, FDM, CDM, or WDM.

[0244] In the multiplexing unit 604, information for identifying the output signal of the slave station signal processing unit 603#j (for example, signal ID#j) may be added. For example, a signal ID may be added to each output signal of the slave station signal processing unit 603#j. Also, for example, time slot information in the case of TDM, frequency information in the case of FDM, code information in the case of CDM, and wavelength information in the case of WDM may each play the role of a signal ID.

[0245] Also, the multiplexing unit 604 may be omitted. For example, the outputs of the different slave station signal processing units 603#1 and 603#2 may be input to the FH transmitter 70 in a physically separate manner.

[0246] In addition, the child station signal processing unit 603#1 and the child station signal processing unit 603#2 may be realized by physically different devices, or may be realized by being logically divided within the same device using, for example, virtualization technology.

[0247] The number of the child station signal processing units 603#j may be two or more, and may be changed dynamically or adaptively in the case of logical division. For example, as described above, when the service type supported by the wireless base station 1 changes, the number of slices #j corresponding to the child station signal processing units 603#j may be increased or decreased in accordance with an increase or decrease in the number of slices #j corresponding to the child station signal processing units 603#j.

[0248] Furthermore, one or both of the RF unit 601 and the A / D conversion unit 602 illustrated in FIG. 13 may be provided individually for the different child station signal processing units 603#j.

[0249] (FH transmitter 70) Next, an example of the configuration of FH transmitter 70 according to the fourth embodiment will be described with reference to FIG.

[0250] As shown in FIG. 14, FH transmitter 70 includes, for example, a demultiplexer 701, FH transmission processors 702-1 and 702-2, a multiplexer 703, a transmitter 704, a controller 705, a training data unit 706, and a transmitter 707.

[0251] FH transmission processing units 702-1 and 702-2 may be written as FH transmission processing units 702#1 and 702#2, respectively. Furthermore, when there is no need to distinguish between FH transmission processing units 702-1 and 702-2, they may be written as FH transmission processing units 702. The number of FH transmission processing units 702 provided in FH transmitter 70 is not limited to two, and may be three or more. For example, N FH transmission processing units 702 corresponding to the number N of service types may be written as FH transmission processing units 702#j (j=1 to N).

[0252] The FH transmission processing unit 702#1 and the FH transmission processing unit 702#2 may be realized by physically different devices, or may be realized, for example, by being divided into software or hardware circuits within the same device.

[0253] The demultiplexer 701 demultiplexes the UL multiplexed signal received from the local station processor 60 according to service type #j, for example, based on the signal ID described above, and outputs the signals to the corresponding FH transmission processors 702#j. The demultiplexer 701 also demultiplexes control information multiplexed in the UL signal received from FH13, for example, and outputs the control information to the controller 705. The control information may include, for example, information on the MCS used in the MAC unit 6038.

[0254] When the multiplexing unit 604 is omitted in the slave station processing device 60, the demultiplexing unit 701 may also be omitted. For example, the outputs of the different slave station signal processing units 603#1 and 603#2 may be physically separated and input to the FH transmission processing units 702#1 and 702#2, respectively.

[0255] The control unit 705 decodes the control information input from the demultiplexing unit 701 and outputs the decoded control information to the FH transmission processing unit 702#j.

[0256] Each of the FH transmission processing units 702#j includes, for example, an encoding unit 7021 and a modulation unit 7022.

[0257] The encoding unit 7021 decodes the output of the demodulation unit 4031 in accordance with control information from the control unit 705, for example.

[0258] The modulation unit 7022 modulates the output of the encoding unit 7021 in accordance with control information from the control unit 705, for example.

[0259] The multiplexing unit 703, for example, multiplexes the outputs of a plurality of different FH transmission processing units 702#j and outputs the multiplexed signals to the transmission unit 704. The signals multiplexed in the multiplexing unit 703 may be considered to correspond to signals addressed to a plurality of different master station signal processing units in the master station processing device 90 (for example, master station signal processing units 902#1 and 902#2 described later in FIG. 16).

[0260] As a non-limiting example, TDM, FDM, CDM, or WDM may be applied as the multiplexing method in the multiplexing unit 703. In the multiplexing unit 703, information for identifying the output signal of the FH transmission processing unit 702#j (e.g., signal ID#j) may be added. For example, a signal ID may be added to each output signal of the FH transmission processing unit 702#j. Also, for example, time slot information in the case of TDM, frequency information in the case of FDM, code information in the case of CDM, and wavelength information in the case of WDM may each play the role of a signal ID.

[0261] The transmitting unit 704 performs transmission processing on the output of the multiplexing unit 703 according to a wired transmission means (or a wired interface) such as a UTP cable, an STP cable, or an optical fiber cable, and transmits the processed signal to the FH 13 .

[0262] The training data section 706 , like the above-described training data section 406 , generates a known signal (for example, a training signal) for measuring the transmission quality of FH13, and outputs the signal to the transmitting section 707 .

[0263] The transmitter 707 transmits, for example, a known signal to the FH 13 connected to the master station device 11 (for example, the FH receiver 80). The known signal transmitted to the FH 13 is received, for example, by the receiver 801 (see FIG. 15) of the FH receiver 80 in the master station device 11.

[0264] In addition, measurement of FH13 transmission quality using a known signal may be performed by transmitting a known signal from FH receiver 80 to FH transmitter 70, measuring the FH13 transmission quality in FH transmitter 70, and feeding back the measurement results to FH receiver 80.

[0265] Furthermore, control section 705, training data section 706, and transmission section 707 may be common to control section 405, training data section 406, and transmission section 407, respectively, illustrated in Fig. 4. In other words, a transmission system for known signals and a control system for FH transmission quality may be shared between DL and UL.

[0266] In addition, one or both of the functions of the training data unit 706 and the transmission unit 707 may be included in the control unit 705. The control unit 705, the training data unit 706, and some or all of the transmission unit 707 may be provided outside the FH transmitter 70, as long as they are provided in the slave station device 12.

[0267] <Master station device 11> Next, an example of a configuration focusing on the UL of the master station device 11 will be described with reference to FIG. 15 and FIG.

[0268] (FH receiver 80) Fig. 15 is a block diagram showing an example of the configuration of FH receiver 80 provided in master station device 11. As shown in Fig. 15, FH receiver 80 includes, for example, a receiving unit 801, a separating unit 802, FH reception processing units 803-1 and 803-2, a multiplexing unit 804, a receiving unit 805, a measuring unit 806, and a control unit 807.

[0269] FH reception processing units 803-1 and 803-2 may be written as FH reception processing units 803#1 and 803#2, respectively. Furthermore, when there is no need to distinguish between FH reception processing units 803-1 and 803-2, they may be written as FH reception processing units 803. The number of FH reception processing units 803 provided in FH receiver 80 is not limited to two, and may be three or more. For example, N FH reception processing units 803 corresponding to the number N of service types may be written as FH reception processing units 803#j (j=1 to N).

[0270] The FH reception processing section 803#1 and the FH reception processing section 803#2 may be realized by physically different devices, or may be realized, for example, by being divided into software or hardware circuits within the same device.

[0271] The receiver 801 receives the UL signal from the slave station equipment 12 via the FH 13, performs reception processing according to the wired transmission means (or wired interface) such as a UTP cable, an STP cable, or an optical fiber cable, and outputs the processed signal to the separator 802.

[0272] The separator 802 separates signals corresponding to the different slave station signal processors 603#j from the output of the receiver 801, for example, based on the signal ID described above, and outputs the separated signals to the FH receiver 803#j.

[0273] The receiver 805 receives, for example, a known signal (for example, a training signal) transmitted from the FH transmitter 70 of the slave station device 12 and propagated through FH 13, and outputs the signal to the measurement unit 806.

[0274] The measurement section 806 measures the reception quality of the known signal input from the reception section 805, and outputs the quality measurement result to, for example, the control section 807.

[0275] Based on the quality measurement results by the measurement unit 806, the control unit 807 determines FH transmission parameters (e.g., one or more of the code type, coding rate, and modulation multi-level number) #j corresponding to each of the child station signal processing units 603#j, and outputs them to the FH reception processing units 803#1 and 803#2.

[0276] The control unit 807 may, for example, encode and modulate control information addressed to the slave station device 12 and transmit the encoded control information to the control unit 705 of the FH transmitter 70. The control information may include, for example, the determined FH transmission parameters. Additionally or alternatively, the control information may include a quality measurement result by the measurement unit 806.

[0277] Each FH reception processing unit 803#j includes a demodulation unit 8031 ​​and a decoding unit 8032.

[0278] The demodulation section 8031 ​​demodulates the output of the separation section 802, for example, in accordance with control information (for example, FH transmission parameter #j) from the control section 807.

[0279] The decoder 8032 decodes the output of the demodulator 8031 ​​in accordance with, for example, control information (for example, FH transmission parameter #j) from the controller 807.

[0280] The multiplexing unit 804, for example, multiplexes the outputs of a plurality of different FH reception processing units 803#j and outputs the multiplexed signals to the master station processing device 90. The signals multiplexed in the multiplexing unit 804 may be considered to correspond to signals addressed to a plurality of different slave station signal processing units in the master station processing device 90 (for example, master station signal processing units 902#1 and 902#2 in FIG. 16).

[0281] As a non-limiting example, the multiplexing method used in the multiplexing unit 804 may be TDM, FDM, CDM, or WDM. In the multiplexing unit 804, information for identifying the output signal of the FH reception processing unit 803#j (e.g., signal ID#j) may be added. For example, a signal ID may be added to each output signal of the FH transmission unit#j. Also, for example, the signal ID may be time slot information in the case of TDM, frequency information in the case of FDM, or wavelength information in the case of WDM.

[0282] Also, the multiplexing unit 804 may be omitted. For example, the outputs of the different FH reception processing units 803#1 and 803#2 may be input to the master station processor 90 in a physically separate manner.

[0283] Furthermore, the receiver 805, the measurement unit 806, and the control unit 807 may be common to the receiver 305, the measurement unit 306, and the control unit 307 illustrated in Fig. 3. In other words, the measurement system using a known signal and the control system for the FH transmission quality may be shared between DL and UL.

[0284] (Master station processor 90) Next, an example of the configuration of the master station processing device 90 will be described with reference to Fig. 16. As illustrated in Fig. 16, the master station processing device 90 includes, for example, a separation unit 901, master station signal processing units 902-1 and 902-2, a service class multiplex unit 903, and an FH quality calculation unit 904.

[0285] The master station signal processing units 902-1 and 902-2 may be written as master station signal processing units 902#1 and 902#2, respectively. When the master station signal processing units 902-1 and 902-2 are not to be distinguished from each other, they may be written as master station signal processing units 902. The number of master station signal processing units 902 provided in the master station processing device 90 is not limited to two, and may be three or more. For example, assuming that the number of service types is N (N is an integer equal to or greater than two), the N master station signal processing units 902 may be written as master station signal processing units 902#j (j=1 to N).

[0286] 16, the master station signal processing unit 902#1 includes, for example, an RE (resource element) demapping unit 9021, a layer demapping unit 9022, a demodulation unit 9023, a descrambling unit 9024, and a decoding unit 9025. These functional units 9021 to 9024 form a High-PHY block 9001.

[0287] The master station signal processing unit 902#1 also includes, for example, a MAC unit 9026, an RLC unit 9027, a PDCP unit 9028, and an SDAP unit 9029.

[0288] The above-mentioned functional units 9021 to 9029, together with the functional units 6031 and 6032 in the child station signal processing unit 603#1, are non-limiting examples of a plurality of base station functional units (related to UL) included in the wireless base station 1.

[0289] The RE demapping unit 9021, for example, demaps the UL signal corresponding to the service type #1 separated in the separation unit 901 from a predetermined radio resource (for example, RE).

[0290] The layer demapping unit 9022, for example, demaps the UL signal mapped for each layer at the output of the RE demapping unit 9021. Note that since the layer demapping unit 9022 is used for MIMO transmission, it may be omitted when MIMO transmission is not applied.

[0291] The demodulation unit 9023 demodulates the output of the layer demapping unit 9022, for example, using a demodulation method corresponding to a modulation method such as QPSK, 16QAM, 64QAM, or 256QAM.

[0292] The descrambling unit 9024 performs a descrambling process for removing the scrambling from the output of the demodulation unit 9023, for example.

[0293] The decoding unit 9025, for example, decodes the output of the descrambling unit 9024.

[0294] The MAC unit 9026 generates an RLC PDU from the MAC PDU and outputs a transport block. The MAC unit 9026 also performs, for example, retransmission control using HARQ, determination of UE2 to which UL communication opportunities are assigned using scheduling, and determination of MCS for UL wireless transmission, and transmits control information to UE2 via a physical downlink control channel (PDCCH).

[0295] Here, the MCS may be determined based on, for example, the CQI fed back from UE 2, the communication quality required for each service type, and the FH transmission quality information input from FH quality calculation section 904.

[0296] The RLC section 9027 performs processes such as error detection and retransmission control using ARQ on the output of the MAC section 9026, and outputs a PDCP PDU.

[0297] The PDCP section 9028 performs processing on the output of the RLC section 9027 , such as decrypting encrypted user data and decompressing the header, and outputs an SDAP PDU to an SDAP section 9029 .

[0298] The SDAP unit 9029, for example, performs mapping between a QoS flow and a radio bearer, removes the SDAP header from the output of the PDCP unit 9028, and transmits the result to the upper core network.

[0299] An FH quality calculation section (or FH quality determination section) 904 determines FH transmission quality information based on information on the FH transmission quality measured by a measurement section 806 in the FH receiver 80 and fed back to the master station processor 90 .

[0300] The FH transmission quality information is input, for example, to the MAC unit 9026 in at least one master station signal processing unit 902#1. Additionally, the FH transmission quality information may also be input to the MAC unit 9026 in another master station signal processing unit 902#j (for example, j=2) different from the master station signal processing unit 902#1.

[0301] The MAC unit 9026 calculates the transmission quality of the UL propagation path that integrates the FH propagation path and the wireless propagation path, for example, based on the wireless quality information indicated by the CQI fed back from the UE 2 and the FH transmission quality information. Then, the MAC unit 9026 determines the MCS so that the transmission quality when data is propagated through the integrated propagation path satisfies the required quality according to the service type.

[0302] As a non-limiting example, the MAC unit 9026 combines the SNR of the UL radio transmission section and the SNR of the UL FH transmission section. Based on the combined SNR, the MAC unit 9026 determines an MCS suitable for the integrated UL propagation path including the radio transmission section and the FH transmission section.

[0303] Also in the fourth embodiment, when quality degradation in FH transmission is permitted, an MCS capable of compensating for the permitted signal quality degradation in FH transmission may be selected in determining the MCS (in other words, in controlling the wireless transmission method).

[0304] Then, the MAC unit 9026 outputs to the High-PHY block 9001 control information such as information on the determined MCS and information on resources (eg, resource elements (RE)) or layers used for UL wireless transmission.

[0305] 16, the master station signal processing unit 902#2 includes, for example, a PDCP unit 9028 and an SDAP unit 9029. The functions of the PDCP unit 9028 and the SDAP unit 9029 may be the same as or similar to those in the master station signal processing unit 902#1.

[0306] In other words, the master station signal processing unit 902#2 does not include an RE demapping unit 9021, a layer demapping unit 9022, a demodulation unit 9023, a descrambling unit 9024, a decoding unit 9025, a MAC unit 9026, and an RLC unit 9027. Functional units equivalent to these functional units 9021 to 9027 are arranged in the slave station processing device 60 (slave station signal processing unit 603#2) as illustrated in FIG.

[0307] Therefore, with respect to the UL, the master station signal processing unit 902#2 has a different functional division configuration from the master station signal processing unit 902#1. In other words, with respect to the UL, the functional division points regarding the base station functions of the master station signal processing unit 902#1 and the master station signal processing unit 902#2 are different from each other.

[0308] Next, in Fig. 16, the service class multiplexing unit 903 multiplexes UL signals for each service type, which are outputs from the parent station signal processing units 902#1 and 902#2, and transmits the multiplexed signals to a higher-level core network (for example, EPC or 5GC). Note that the location of the service class multiplexing unit 903 is not limited to the location shown in Fig. 16. For example, the service class multiplexing unit 903 may be arranged before a PDCP unit 9028 or an SDAP unit 9029, which will be described later.

[0309] Note that the separator 901 may be omitted if the multiplexer 804 is omitted in the FH receiver 80 illustrated in Fig. 15. For example, the outputs of different FH reception processors 803-1 and 803-2 may be physically separated and input to master station signal processors 902-1 and 902-2, respectively.

[0310] In addition, the master station signal processing unit 902-1 and the master station signal processing unit 902-2 may be realized by physically different devices, or may be realized by logically divided slices within the same device using, for example, virtualization technology.

[0311] Also, the number of UL parent station signal processors 902 may be two or more as described above, and may be changed dynamically or adaptively in the case of logical division. For example, when the service type supported by the wireless base station 1 changes, a configuration suitable for the service type can be realized by increasing or decreasing the number of slices in response to the change.

[0312] For example, in the radio base station 1, slices suitable for the service type supported in the UL, such as a slice for eMBB, a slice for URLLC, or a slice for mMTC, can be added or deleted as necessary. Therefore, a UL base station configuration suitable for the service type can be flexibly realized.

[0313] Regarding the UL, at least one of the master station processing device 90 and the slave station processing device 60 may be configured by a logical slice.

[0314] (Example of operation) An example of operation focusing on the UL in embodiment 4 corresponds to, for example, an operation in which the flow of "user data" in the sequence diagram illustrated in FIG. 6 in embodiment 1 is reversed and the master station processing device 20, FH transmitter 30, FH receiver 40, and slave station processing device 50 are replaced with the master station processing device 90, FH receiver 80, FH transmitter 70, and slave station processing device 60, respectively.

[0315] As described above, according to the fourth embodiment, it is possible to obtain the same operational effects as those of the first embodiment with respect to UL.

[0316] The measurement section 806 of the FH receiver 80 may include the function of the FH quality calculation section 904 (see FIG. 16) of the master station processing device 90. In that case, the master station processing device 90 does not need to be provided with the FH quality calculation section 904.

[0317] Furthermore, the FH quality calculation unit 904 of the master station processing device 90 and the control unit 807 of the FH receiver 80 may be integrated into a single control unit. For example, the functions of one of the FH quality calculation unit 904 and the control unit 807 may be included in the other of the FH quality calculation unit 904 and the control unit 807. Furthermore, the measurement unit 806 of the FH receiver 80 may be included in the control unit 807.

[0318] In other words, the functions of the FH quality calculation unit 904 , the measurement unit 806 , and the control unit 807 may be provided in the master station device 11 .

[0319] (Embodiment 5) The UL configuration corresponding to the second embodiment corresponds to a configuration in which the FH quality calculation unit 904 in the master station processor 90 illustrated in Fig. 16 is replaced with a functional unit equivalent to the target quality setting unit 205 illustrated in Fig. 7 of the second embodiment. Also, in the FH receiver 80 illustrated in Fig. 15, the measurement unit 806 does not need to feed back FH transmission quality information, which is the measurement result of the known signal, to the FH quality calculation unit 904.

[0320] In the fifth embodiment, the UL configurations of the slave station processing device 60 and the FH transmitter 70 in the slave station device 12 may be the same as or similar to the configurations exemplified in FIG. 13 and FIG. 14, respectively.

[0321] In addition, in the fifth embodiment, an example of operation focusing on UL corresponds to, for example, an operation in which the flow of "user data" in the sequence diagram illustrated in FIG. 9 of the second embodiment is reversed, and the master station processing device 20, FH transmitter 30, FH receiver 40, and slave station processing device 50 are respectively replaced with the master station processing device 90, FH receiver 80, FH transmitter 70, and slave station processing device 60.

[0322] According to the fifth embodiment, it is possible to obtain the same effect as that of the second embodiment with respect to UL.

[0323] (Embodiment 6) The UL configuration corresponding to the third embodiment corresponds to a configuration in which functional units equivalent to the Ack / Nack calculation unit 408 and the transmission unit 407 illustrated in FIG. 10 of the third embodiment are added to the FH receiver 80 of the parent station device 11 illustrated in FIG. 15.

[0324] In the sixth embodiment, the UL configurations of the master station processing device 90 of the master station device 11, the slave station processing device 60 of the slave station device 12, and the FH transmitter 70 may be the same as or similar to the configurations illustrated in FIGS. 16, 13, and 14, respectively.

[0325] In the sixth embodiment, for example, Ack / Nack statistical information on the UL signal is obtained in the FH receiver 80. The Ack / Nack statistical information is transmitted to, for example, the control unit 807 of the FH receiver 80 and the FH quality calculation unit 904 of the master station processing device 90. As a result, the transmission parameters of the UL radio section and the FH transmission section are controlled based on the Ack / Nack statistical information.

[0326] According to the sixth embodiment, it is possible to obtain the same effect as that of the third embodiment with respect to UL.

[0327] (others) In the above-mentioned first to sixth embodiments, the description has been given focusing on the one-to-one connection relationship between the master station equipment 11 and the slave station equipment 12, but the connection relationship between the master station equipment 11 and the slave station equipment 12 may be a one-to-many relationship.

[0328] When signals of different service types are multiplexed in the FH transmitter 30 (or 70) and the FH receiver 40 (or 80), the number of known signal patterns for FH transmission quality measurement may be prepared equal to the number of multiplexes (the number of service types). In this case, it is expected that the accuracy of FH transmission quality measurement for each service type will be improved.

[0329] The notation "... unit" used in the above-mentioned first to sixth embodiments may be replaced with other notations such as "... circuit", "... device", "... unit", or "... module" when referring to a physical element. In contrast, when referring to a logical element, the notation "... unit" may be replaced with, for example, "slice" as described above.

[0330] The term "functional division point" used in the above-mentioned first to sixth embodiments may also be called "split," "option," or "split option."

[0331] For example, Non-Patent Document 2 specifies splits A to E. Furthermore, as an example of the "split option", for example, as described in Non-Patent Document 3, the following split options 1 to 8 can be given.

[0332] (1) Split Option 1: Between RRC (radio resource control) and PDCP (2) Split Option 2: Between PDCP and RLC (High-RLC) (3) Split Option 3: Between High-RLC and Low-RLC (4) Split Option 4: Between RLC (Low-RLC) and MAC (High-MAC) (5) Split Option 5: Between High-MAC and Low-MAC (6) Split Option 6: Between MAC (Low-MAC) and PHY (High-PHY) (7) Split Option 7: Between High-PHY and Low-PHY (8) Split Option 8: Between PHY (Low-PHY) and RF

[0333] As shown in the above division options 1 to 8, in the first to sixth embodiments, each of the RLC section and the MAC section may be functionally divided (or classified) into a higher section (High) and a lower section (Low).

[0334] The functional division configuration between the parent station signal processing unit 202#1 and the child station signal processing unit 502#1 for DL, and the functional division configuration between the parent station signal processing unit 902#1 and the child station signal processing unit 603#1 for UL, illustrated in embodiments 1 to 6, correspond to "split D" or "split option 7".

[0335] In contrast, the functional division configuration between the parent station signal processing unit 202#2 and the child station signal processing unit 502#2 for DL, and the functional division configuration between the parent station signal processing unit 902#2 and the child station signal processing unit 603#2 for UL, illustrated in embodiments 1 to 6, correspond to "split B" or "split option 2".

[0336] The functional division configuration between the parent station signal processing unit (202 / 902) #j and the child station signal processing unit (502 / 603) #j may adopt any of the splits (or split options) A to E (or split options 1 to 8) as long as it is a combination of different splits (or split options).

[0337] Any one of the splits A to E (or split options 1 to 8) may be further split (or classified) as a "sub-split" (or a "sub-option"). The "sub-split" (or the "sub-option") may be included in combination candidates of different functional split configurations.

[0338] In the first to sixth embodiments, the case where there is one functional division point (the functional division configuration has two, the master station device 11 and the slave station device 12) has been described, but there may be two or more functional division points. For example, a plurality of base station functional units may be divided and arranged into three, a CU, a DU, and a RU (radio unit), by two functional division points.

[0339] In this case, for example, the connection between the CU and the DU corresponds to FH 13. For example, based on information indicating the transmission quality of FH 13 between the CU and the DU, the transmission quality (for example, transmission parameters) between the CU-DU and between the DU-RU may be individually controlled so that the transmission quality of the integrated propagation path of the CU-DU-RU satisfies the required quality.

[0340] The present disclosure can be realized by software, hardware, or software in cooperation with hardware. Each functional block used in the description of the above embodiment may be realized partially or entirely as an LSI, which is an integrated circuit, and each process described in the above embodiment may be controlled partially or entirely by one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of one chip so as to include some or all of the functional blocks. The LSI may have input and output of data. Depending on the degree of integration, the LSI may be called an IC, a system LSI, a super LSI, or an ultra LSI.

[0341] The integrated circuit method is not limited to LSI, and may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. After LSI manufacturing, a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. The present disclosure may be realized as digital processing or analog processing.

[0342] Furthermore, if a new integrated circuit technology that can replace LSI appears due to the progress of semiconductor technology or a derivative technology, it is possible to integrate the functional blocks using that technology. The application of biotechnology is also a possibility.

[0343] <Summary of this disclosure> A parent station device according to one non-limiting embodiment of the present disclosure is connected to a child station device via a fronthaul, and includes a first base station signal processing unit having a first functional division configuration for a plurality of base station function units for a first service type, and a second base station processing unit having a second functional division configuration for the plurality of base station function units for a second service type.

[0344] Here, a master station device according to a non-limiting embodiment of the present disclosure may include a control unit that determines a transmission method for the fronthaul, separately for the first base station signal processing unit and the second base station processing unit.

[0345] In addition, in a non-limiting embodiment of the present disclosure, the control unit may determine a transmission method for the fronthaul and a wireless transmission method for the slave station device based on information indicating a transmission quality of the fronthaul.

[0346] In one non-limiting embodiment of the present disclosure, the information indicating the transmission quality of the fronthaul may be based on the results of quality measurements of a known signal between the master station device and the slave station device that transmitted the fronthaul.

[0347] In one non-limiting embodiment of the present disclosure, the known signal may be transmitted from the slave station device to the master station device via the fronthaul, and the master station device may be provided with a measurement unit that measures the quality of the known signal.

[0348] In one non-limiting embodiment of the present disclosure, the known signal may be transmitted from the parent station device to the child station device via the fronthaul, and the information indicating the transmission quality of the fronthaul may be feedback information of the result of the child station device measuring the quality of the known signal.

[0349] In one non-limiting embodiment of the present disclosure, the information indicating the transmission quality of the fronthaul may be based on an error determination result of the data transmitted through the fronthaul.

[0350] In one non-limiting embodiment of the present disclosure, the control unit may determine a transmission method for the fronthaul and a wireless transmission method for the slave station device based on information regarding a specified target quality.

[0351] A slave station device according to one non-limiting embodiment of the present disclosure is connected to a master station device via a fronthaul, and includes a first base station signal processing unit having a first functional division configuration for a plurality of base station function units for a first service type, and a second base station processing unit having a second functional division configuration for the plurality of base station function units for a second service type.

[0352] A slave station device according to a non-limiting embodiment of the present disclosure may include a transmission unit that transmits a known signal to the master station device between the master station device and the slave station device.

[0353] In one non-limiting embodiment of the present disclosure, the slave station device may feed back to the master station device the quality measurement results at the slave station device of a signal transmitted by the master station device and known between the master station device and the slave station device.

[0354] A communication control method according to a non-limiting embodiment of the present disclosure includes a parent station device connected to a child station device via a fronthaul, which acquires information indicating a transmission quality of the fronthaul, and determines a transmission method of the fronthaul based on the information indicating the transmission quality of the fronthaul, separately for a first base station signal processing unit having a first functional division configuration for a plurality of base station function units for a first service type, and a second base station processing unit having a second functional division configuration for the plurality of base station function units for a second service type.

[0355] A communication control method according to one non-limiting embodiment of the present disclosure, in which a slave station device connected to a master station device via a fronthaul transmits a signal for the master station device to measure the transmission quality of the fronthaul, and determines a transmission method of the fronthaul based on information indicating the transmission quality of the fronthaul, separately for a first base station signal processing unit having a first functional division configuration for a plurality of base station function units for a first service type, and a second base station processing unit having a second functional division configuration for the plurality of base station function units for a second service type. [Industrial Applicability]

[0356] The present disclosure is suitable for, for example, a base station for wireless communication. [Explanation of symbols]

[0357] 1. Radio base station 2. UE 11 Master station device 12 Slave station device 13 FH 20,90 Master station processing device 202-1, 202-2, 902-1, 902-2 Parent station signal processing unit 204,904 FH quality calculation section 30,70 FH transmitter 306,806 Measuring part 40,80 FH receiver 406,706 Training Data Section 407,707 Transmitter 50,60 Slave station processing device 502-1, 502-2, 603-1, 603-2 Slave station signal processing section

Claims

1. A communication system including a slave station device and a master station device connected to the slave station device via a fronthaul, The master station device includes: a first base station signal processing unit having a first functional division configuration relating to a plurality of base station function units for a first service type; a second base station signal processing unit having a second functional division configuration related to the plurality of base station function units for a second service type; a control unit that controls a transmission method of the fronthaul of the first base station signal processing unit in accordance with the first functional division configuration, and controls a transmission method of the fronthaul of the second base station signal processing unit in accordance with the second functional division configuration; Equipped with the control unit, when the first functional division configuration includes an upper physical layer and the second functional division configuration does not include an upper physical layer, performs control to apply fronthaul transmission with lower redundancy than a transmission method of the second base station signal processing unit to a transmission method of the first base station signal processing unit in fronthaul transmission to the slave station device, The slave station device a first slave station device side base station signal processing unit having a first functional division configuration relating to a plurality of base station function units for the first service type; a second slave station device side base station signal processing unit having a second functional division configuration related to the plurality of base station function units for the second service type; a slave station device side control unit that controls a transmission method of the fronthaul of the first base station signal processing unit in accordance with the first functional division configuration, and controls a transmission method of the fronthaul of the second base station signal processing unit in accordance with the second functional division configuration; Equipped with Communication systems.

2. The control unit is determining a transmission method for the fronthaul and a wireless transmission method for the slave station device based on information indicating a transmission quality of the fronthaul; The communication system according to claim 1 .

3. The information indicating the transmission quality of the fronthaul is based on a result of a quality measurement of a known signal between the master station device and the slave station device that has transmitted the fronthaul. The communication system according to claim 2.

4. the known signal is transmitted from the slave station device to the master station device via the fronthaul, and the master station device is provided with a measurement unit that measures quality of the known signal. The communication system according to claim 3.

5. the known signal is transmitted from the master station device to the slave station device via the fronthaul, and the information indicating the transmission quality of the fronthaul is feedback information indicating a result of measurement of the quality of the known signal by the slave station device. The communication system according to claim 3.

6. The information indicating the transmission quality of the fronthaul is based on an error determination result of the data transmitted through the fronthaul. The communication system according to claim 2.

7. The control unit is determining a transmission method for the fronthaul and a wireless transmission method for the slave station device based on information about a specified target quality; The communication system according to claim 1 .

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