Wireless communication device and wireless communication system

Abstract

A wireless communication device according to the present invention has a control unit and a transmission unit. The control unit selects a first index for indicating modulation schemes for a plurality of frequency bands from among a plurality of indices. The first index indicates that a first frequency band of the plurality of frequency bands corresponds to a first modulation scheme and indicates that a second frequency band of the plurality of frequency bands that is different from the first frequency band corresponds to a second modulation scheme. The transmission unit transmits the first index selected by the control unit to a first wireless communication device.

Description

Wireless communication device and wireless communication system

[0001] The present invention relates to a wireless communication device and a wireless communication system.

[0002] Currently, the 3rd Generation Partnership Project (3GPP: 3RD GENERATION PARTNERSHIP PROJECT (registered trademark)), an international standardization project, is currently requiring networks to support services with diverse requirements. In order to support such diverse services, for example, in the communication standards (Non-Patent Documents 1 to 10) of fifth-generation mobile communications (5G or NR (New radio)), standards are being developed assuming support for many use cases classified as eMBB (Enhanced Mobile Broadband), massive MTC (Machine Type Communications), and URLLC (Ultra-Reliable and Low Latency Communications).

[0003] The currently used fifth generation mobile communication system (hereinafter referred to as 5G) uses a maximum width of 500 MHz in the 3.7 GHz band and 4.5 GHz band, and a maximum width of 2 GHz in the 28 GHz band.

[0004] Furthermore, a technology is being considered that utilizes radio waves in the ultra-high frequency band of 100 GHz or more (sub-terahertz waves, terahertz waves, etc.) in a continuous bandwidth of several tens of GHz (Non-Patent Document 11).

[0005] 3GPP TS 38.211 V18.1.03GPP TS 38.212 V18.1.03GPP TS 38.213 V18.1.03GPP TS 38.214 V18.1.03GPP TS 38.215 V18.1.03GPP TS 38.300 V18.0.03GPP TS 38.321 V18.0.03GPP TS 38.322 V18.0.03GPP TS 38.323 V18.0.03GPP TS 38.331 V18.0.0Recommendation ITU-R M.2160-0 (11 / 2023)

[0006] However, radio waves in high frequency bands are easily affected by the transmission characteristics and reception characteristics of the device being used, propagation loss of the propagation path, etc. Therefore, for example, when communication is performed using a wide bandwidth and high frequency band, the communication quality is easily affected by the characteristics of the device and the propagation path, and differences in communication quality within a single bandwidth are likely to occur, making it difficult to utilize radio resources according to the communication quality for each frequency.

[0007] On the other hand, in wide-band communications, it is possible to divide a wide-band frequency band into smaller parts and change the modulation method, but it is necessary to specify the modulation method according to the number of divisions. Therefore, a control signal corresponding to the number of divisions is transmitted. As a result, the number of signals required to specify the modulation method increases, which may cause communication congestion. Note that although the example of a high-frequency band has been used in the explanation, the same problem may occur in other frequencies as well.

[0008] The disclosed technology has been made in view of the above, and aims to reduce the number of signals when multiple modulation methods are used within a predetermined frequency band.

[0009] In one aspect, a wireless communication device includes a control unit that selects a first index from a plurality of indexes, and a transmission unit that transmits the first index to a first wireless communication device, wherein the first index indicates that a first frequency band corresponds to a first modulation method and a second frequency band corresponds to a second modulation method.

[0010] When multiple modulation methods are used within a given frequency band, the number of signals can be reduced.

[0011] FIG. 1 is a diagram showing an example of a wireless communication system according to a first embodiment. FIG. 2 is a diagram showing an example of a functional block configuration of a base station. FIG. 3 is a diagram showing an example of a functional block configuration of a terminal. FIG. 4 is a diagram showing an example of a table indicating the relationship between indexes and combinations of modulation schemes for multiple frequency bands. FIG. 5 is a diagram showing an example of a sequence of a wireless communication system according to the first embodiment. FIG. 6 is a diagram showing an example of a sequence of a wireless communication system according to the first embodiment. FIG. 7 is a diagram showing an example of a sequence of a wireless communication system according to the first embodiment. FIG. 8 is a diagram showing an example of a sequence of a wireless communication system according to a second embodiment. FIG. 9 is a diagram showing an example of a wireless communication system according to a third embodiment. FIG. 10 is a diagram showing an example of a sequence of a wireless communication system according to the third embodiment. FIG. 11 is a diagram showing an example of a hardware configuration of a base station. FIG. 12 is a diagram showing an example of a hardware configuration of a terminal.

[0012] (Embodiment 1) A wireless communication system 1 according to embodiment 1 will be described with reference to Fig. 1. Fig. 1 is a diagram illustrating an example of the wireless communication system 1 according to embodiment 1. The wireless communication system 1 includes a base station 100, a terminal 200, a server 300, and a core network 400. The base station 100 forms a cell C10, and the terminal 200 is present in the cell C10. The base station 100 can communicate with the terminal 200 in the cell C10. The base station 100 can also communicate with the server 300 via the core network 400.

[0013] The base station 100 may be, for example, a small radio base station such as a macro radio base station or a pico radio base station (including a micro radio base station, a femto radio base station, etc.), or may be a radio base station of various scales, and may be referred to as a radio communication device, a communication device, a transmitting device, etc. Furthermore, the terminal 200 may be a radio terminal such as a mobile phone, a smartphone, a personal digital assistant (PDA), a personal computer, a vehicle, or any other device or equipment (such as a sensor device) having a radio communication function, and may be referred to as a radio communication device, a communication device, a receiving device, a mobile station, etc. Next, the base station 100 will be described using FIG. 2 . FIG. 2 is a diagram showing an example of a functional block configuration of the base station 100. The base station 100 includes a transmitting unit 110, a receiving unit 120, a control unit 130, and a storage unit 140.

[0014] The transmitting unit 110 transmits signals to the terminal 200. Specifically, the transmitting unit 110 can transmit downlink signals such as a random access procedure signal, a Radio Resource Control (RRC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, a signal in the physical layer, a downlink data signal, and a downlink control signal. The transmitting unit 110 can also transmit signals to the server 300 via the core network 400.

[0015] The receiving unit 120 receives uplink signals, such as a random access procedure signal, signals in the RRC layer, the PDCP layer, the MAC layer, the RLC layer, and the physical layer, an uplink data signal, and an uplink control signal, transmitted from the terminal 200. The receiving unit 120 can also receive signals from the server 300 via the core network 400.

[0016] The control unit 130 controls the base station 100. Specifically, the control unit 130 can control the establishment of an RRC connection with the terminal 200, the modulation of signals to be transmitted to the terminal 200, the demodulation of signals received from the terminal 200, the signal processing of signals received by the receiving unit 120, the creation of transmission blocks (TBs), and the mapping of the transmission blocks to radio resources.

[0017] The storage unit 140 can store, for example, a plurality of combinations of modulation methods for each of a plurality of frequency bands and a plurality of indexes corresponding to the combinations.

[0018] Next, the terminal 200 will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of a functional block configuration of the terminal 200. The terminal 200 has a transmitting unit 210, a receiving unit 220, a control unit 230, and a storage unit 240.

[0019] The transmitter 210 transmits signals to the base station 100. Specifically, the transmitter 210 can transmit uplink signals such as a random access procedure signal, signals in the RRC layer, the PDCP layer, the MAC layer, the RLC layer, and the physical layer, uplink data signals, and uplink control signals.

[0020] The receiving unit 220 receives downlink signals transmitted from the base station 100, such as random access procedure signals, signals in the RRC layer, PDCP layer, MAC layer, RLC layer, and physical layer, downlink data signals, and downlink control signals.

[0021] The control unit 230 controls the terminal 200. Specifically, the control unit 230 can control the establishment of an RRC connection with the base station 100, modulation of signals to be transmitted to the base station 100, demodulation of signals received from the base station 100, signal processing of signals received by the receiving unit 220, creation of transmission blocks (TBs), mapping of the transmission blocks to radio resources, and the like.

[0022] The storage unit 240 can store, for example, combinations of modulation methods for each of a plurality of frequency bands and indices corresponding to the combinations.

[0023] The combinations of modulation schemes for a plurality of frequency bands and the indexes corresponding to the combinations stored in the storage unit 140 of the base station 100 and the storage unit 240 of the terminal 200 will be described with reference to FIG.

[0024] FIG. 4 is a diagram showing an example of a table showing the relationship between combinations of modulation methods for each of a plurality of frequency bands and indexes. In FIG. 4, 16QAM (Quadrature Amplitude Modulation) is represented as 16, 64QAM as 64, and QPSK (Quadrature Phase-Shift Keying) as Q. In addition to the modulation methods shown in FIG. 4, for example, 1024QAM, 256QAM, 64QAM, and BPSK (Binary Phase-Shift Keying) may also be used. FIG. 4 shows an example in which one band is divided into 10 frequency bands. In FIG. 4, index No. In the first combination corresponding to index No. 1, frequency bands #1, #2, and #10 correspond to 64QAM, and frequency bands #3 to #9 correspond to 16QAM. In the second combination corresponding to index No. 2, frequency bands #1 to #5 and #7 to #10 correspond to 16QAM, and frequency band #6 corresponds to QPSK. In the third combination corresponding to index No. 3, frequency bands #1 to #4 and #8 to #10 correspond to 16QAM, and frequency bands #5 to #7 correspond to QPSK. In the fourth combination corresponding to index No. 4, frequency bands #1 to #3, #9, and #10 correspond to 16QAM, and frequency bands #4 to #8 correspond to QPSK. In the second combination corresponding to index No. 2, frequency bands #1 to #5 and #7 to #10 correspond to 16QAM, and frequency bands #6 to #7 correspond to QPSK. In the fifth combination corresponding to 5, frequency band #1 corresponds to 16QAM, and frequency bands #2 to #10 correspond to QPSK.

[0025] 4, index No. 1 is an example of a first index, and index No. 2 is an example of a second index. Also, frequency band #1 is an example of a first frequency band, and frequency band #2 is an example of a second frequency band.

[0026] Next, an example of a process for controlling a modulation method used for communication in the first embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram showing an example of a sequence of the wireless communication system 1 in the first embodiment.

[0027] The control unit 130 of the base station 100 selects a combination to be used for communication from among the multiple combinations stored in the storage unit 140 (step S10). The transmission unit 110 of the base station 100 transmits a signal including information on an index corresponding to the combination to be used for communication to the terminal 200 (step S11).

[0028] The signal including the index information is, for example, downlink control information, and may be a signal in any layer of the RRC layer, PDCP layer, MAC layer, RLC layer, or physical layer. The index information may be notified using DCI or MCS.

[0029] The control unit 130 of the base station 100 modulates the signal to be transmitted to the terminal 200 using a modulation method corresponding to the combination to be used for communication selected by the control unit 130 of the base station 100, and the transmitting unit 110 of the base station 100 transmits the signal modulated by the control unit 130 of the base station 100 to the terminal 200 (step S12).

[0030] The modulation method may be any modulation method such as QPSK, 16QAM, 64QAM, 256QAM, or 1024QAM.

[0031] By controlling in this way, it is possible to set a modulation method for each of the multiple frequency bands divided within the bandwidth, and it is also possible to reduce the number of signals or the amount of information compared to when using multiple frequency bands separately.

[0032] Next, a method for controlling the modulation scheme when terminal 200 in the first embodiment transmits a signal to base station 100 will be described with reference to Fig. 6. Fig. 6 is a diagram showing an example of a sequence of wireless communication system 1 in the first embodiment. Note that in Fig. 6, the same steps as in Fig. 5 are given the same reference numerals, and descriptions thereof will be omitted.

[0033] The receiver 220 of the terminal 200 receives from the base station 100 a signal including index information corresponding to the combination of modulation methods to be used for communication selected by the controller 130 of the base station 100 (step S11). The controller 230 of the terminal 200 controls the signal to be transmitted to the base station 100 so as to be modulated using the combination of modulation methods for each of the multiple frequency bands indicated by the received index. The transmitter 210 of the terminal 200 then transmits the modulated signal to the base station 100 (step S13).

[0034] By controlling in this way, it is possible to set a modulation method for each of the multiple frequency bands divided within the bandwidth, and it is also possible to reduce the number of signals or the amount of information compared to when using multiple frequency bands separately.

[0035] Furthermore, the control unit 130 of the base station 100 can also select a combination to be used for communication according to information on the quality of communication received from the terminal 200, for example, CSI (Channel State Information). An example will be described with reference to Fig. 7 in which the base station 100 selects a combination of modulation schemes to be used for communication from a plurality of combinations according to the information on the quality of communication received from the terminal 200, and controls the modulation scheme when the base station 100 transmits a signal to the terminal 200. Fig. 7 is a diagram showing an example of a sequence of the wireless communication system 1 according to the first embodiment. Note that in Fig. 7, the same steps as in Fig. 5 are denoted by the same reference numerals, and description thereof will be omitted.

[0036] The control unit 230 of the terminal 200 measures the quality of communication between the base station 100 and the terminal 200 (step S14). Measurement of communication quality includes, for example, measurement of CSI-RS (Reference Signal) or SSB (Synchronization Signal Block). The transmission unit 210 of the terminal 200 transmits information about the measurement result to the base station 100 (step S15). The control unit 130 of the base station 100 selects a combination of modulation schemes to be used for communication from multiple combinations according to the information about the measurement result (step S16). The subsequent steps are the same as those in FIG. 5.

[0037] It is also possible for terminal 200 to transmit a signal to base station 100 using the selected combination according to the information on the measurement results. In this case, after step S16, similar to Fig. 6, control unit 230 of terminal 200 controls modulation of the signal to be transmitted to base station 100 using the combination of modulation methods for the multiple frequency bands indicated by the received index. Then, transmission unit 210 of terminal 200 transmits the signal modulated by control unit 230 of terminal 200 to base station 100.

[0038] By controlling in this way, it is possible to control the modulation method for each of the multiple frequency bands obtained by dividing the band in accordance with the quality of communication between the base station 100 and the terminal 200. Furthermore, the number of signals or the amount of information can be reduced compared to when a modulation method is set for each of the multiple frequency bands.

[0039] As described above, in the first embodiment, the base station 100 selects a combination of modulation schemes to be used for communication from a plurality of combinations and notifies an index corresponding to the selected combination. By controlling in this manner, for example, it is possible to perform modulation schemes for each of a plurality of frequencies within a bandwidth with a small number of signals. Furthermore, for example, when communicating high-frequency band radio waves over a wide bandwidth, it is possible to appropriately control the modulation schemes of signals while suppressing an increase in the number of signals or the amount of information. (Embodiment 2) In the first embodiment, an example was described in which the base station 100 and the terminal 200 select a combination of modulation schemes to be used for communication from a plurality of combinations and notify an index corresponding to the selected combination. In the second embodiment, an example is described in which the base station 100 generates a combination of modulation schemes and uses the generated combination for communication. In the second embodiment, the base station 100 and the terminal 200 are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0040] An example in which the base station 100 in the second embodiment generates a plurality of combinations of modulation schemes for a plurality of frequency bands and indices corresponding to the combinations, and transmits them to the terminal 200 will be described with reference to Fig. 8. Fig. 8 is a diagram showing an example of a sequence of the wireless communication system 1 in the second embodiment.

[0041] The transmitter 210 of the terminal 200 transmits the reception characteristics of the terminal 200 to the base station 100 (step S20). The terminal 200 can ascertain its own reception characteristics in advance. For example, the reception characteristics can be determined in advance by recording the reception characteristics obtained by measuring the amplitude and phase for each frequency before the terminal 200 is shipped, the reception characteristics calculated from the reception characteristics of the antenna and RF circuit used by the terminal 200, or the reception characteristics of a terminal of the same model as the terminal 200. The control unit 130 of the base station 100 generates a combination of modulation methods for each of a plurality of frequency bands and an index corresponding to the combination, based on, for example, at least one of the transmission characteristics of the base station 100, the reception characteristics of the terminal 200, and the propagation loss for each frequency of the propagation path (step S21). Here, the base station 100 can ascertain in advance the transmission characteristics of its own terminal and the propagation loss for each frequency of the propagation path. The transmission characteristics can be known in advance, for example, by recording the transmission characteristics obtained by measuring the amplitude and phase for each frequency before shipping the base station, the transmission characteristics calculated from the transmission characteristics of the antenna and RF circuit used by the base station 100, or the transmission characteristics of base stations of the same type as the base station 100. Furthermore, the propagation loss for each frequency of the propagation path can be known in advance, for example, by transmitting signals for each frequency from points around the base station when installing the base station and measuring the signals. The transmitter 110 of the base station 100 transmits information regarding the generated combinations and indexes corresponding to each combination to the terminal 200 (step S22). For example, in step S22, the transmitter 110 of the base station 100 transmits information from the table described in FIG. 4.

[0042] Note that the values ​​referenced when generating combinations of modulation schemes corresponding to each of the multiple frequency bands can be changed as appropriate. In the second embodiment, multiple combinations of modulation schemes for the multiple frequency bands are generated using the transmission characteristics of the base station 100, the reception characteristics of the terminal 200, and the propagation loss for each frequency band, but it is also possible to generate multiple combinations of modulation schemes for the multiple frequency bands using at least one of, for example, the reception characteristics of the base station 100, the transmission characteristics of the terminal 200, and the propagation loss for each frequency of the propagation path.

[0043] 8, the reception characteristics of terminal 200 are referenced, and therefore transmission unit 210 of terminal 200 transmits the reception characteristics of terminal 200 to base station 100 (step S20). However, if control unit 130 of base station 100 references the transmission characteristics of terminal 200, transmission unit 210 of terminal 200 transmits the transmission characteristics of terminal 200 in step S20. If control unit 130 of base station 100 does not reference the reception characteristics or transmission characteristics of terminal 200, step S20 is not necessary. In that case, control unit 130 of terminal 100 generates a combination of modulation schemes corresponding to each of a plurality of frequency bands according to the required values, without receiving a signal from terminal 200.

[0044] Here, an example of generating a plurality of combinations of modulation methods for a plurality of frequency bands and indexes corresponding to the combinations in step S21 will be described.

[0045] In the second embodiment, the control unit 130 of the base station 100 calculates the communication quality for each frequency based on at least one of the transmission characteristics of the base station 100, the reception characteristics of the terminal 200, and the propagation loss for each frequency of the propagation path, and determines a modulation scheme for each of the multiple frequency bands according to the calculated communication quality for each frequency. As an example of a method for allocating modulation schemes to each frequency band, a modulation scheme that can transmit a large number of bits at one time is used for frequency bands with high communication quality, and a modulation scheme that is less susceptible to noise and interference is used for frequency bands with low communication quality. For example, QPSK is less susceptible to noise and interference, but the number of bits that can be transmitted at one time is small, so it is used for frequency bands with low communication quality. Meanwhile, 256QAM can transmit a large number of bits at one time, but is more susceptible to noise and interference, so it is used for frequency bands with high communication quality. In this way, a modulation scheme is determined and combined according to the communication quality for each frequency band.

[0046] Here, the control unit 130 of the base station 100 can also determine the bandwidth for each frequency band. The bandwidth of the frequency band may be a bandwidth set in advance, or may be determined in accordance with the communication quality for each frequency calculated by the control unit 130 of the base station 100. If the bandwidth of the frequency band is set in advance, the transmission unit 110 of the base station 100 transmits a modulation method corresponding to each of the multiple frequency bands in step S22. If the bandwidth is determined in accordance with the communication quality for each frequency, the transmission unit 110 of the base station 100 transmits the bandwidth for each of the multiple frequency bands and the corresponding modulation method in step S22.

[0047] When determining a combination of modulation schemes according to the communication quality for each frequency band, multiple combinations may be generated, for example, by preparing multiple combinations according to CSI measurement results, assuming multiple propagation path environments, or by other various combination generation methods.

[0048] Furthermore, when grasping the communication quality, it is not only possible to calculate based on the values ​​of the transmission characteristics of the base station 100, the reception characteristics of the terminal 200, and the propagation loss of the propagation path for each frequency, but also to grasp the communication quality for each frequency by transmitting and receiving a measurement signal between the base station 100 and the terminal 200. It is also possible to generate a combination of multiple frequency bands and modulation methods for each frequency band according to the measured communication quality for each frequency.

[0049] In the second embodiment, it is assumed that a signal is transmitted from base station 100 to terminal 200, but it is also possible to generate a plurality of combinations of modulation schemes for a plurality of frequency bands suitable for transmitting a signal from terminal 200 to base station 100, and indices corresponding to the combinations. In this case, it is preferable to refer to at least one of the reception characteristics of base station 100, the propagation characteristics of the propagation path, and the transmission characteristics of terminal 200, but the value to be referred to can be changed as appropriate.

[0050] By controlling in this way, the modulation method can be determined for each frequency band, and the modulation method can be defined according to the communication quality for each frequency band. Furthermore, when changing the modulation method for each frequency band, the number of signals or the amount of information can be reduced compared to when a modulation method is set for each of multiple frequency bands.

[0051] As described above, in the second embodiment, the base station 100 generates a combination of modulation schemes for each of a plurality of frequency bands and an index corresponding to the combination based on at least one of the transmission characteristics of the base station 100, the reception characteristics of the terminal 200, and the propagation loss of the propagation path for each frequency. By controlling in this manner, it is possible to generate a combination that is suited to the terminal, the base station, and the transmission path that uses the modulation scheme for each frequency band for communication, for example, when performing communication over a wide bandwidth. Furthermore, as in the first embodiment, the combination of modulation schemes for each frequency band is notified using an index. By controlling in this manner, it is possible to perform modulation schemes for each of a plurality of frequencies within a band with fewer signals. Furthermore, for example, when communicating radio waves in a high frequency band over a wide bandwidth, it is possible to appropriately control the modulation scheme of a signal while suppressing an increase in the number of signals or the amount of information. (Embodiment 3) In the first embodiment, an example was described in which the base station 100 and the terminal 200 select a combination of modulation schemes to use for communication from a plurality of combinations and notify an index corresponding to the selected combination. Furthermore, in the second embodiment, an example was described in which the base station 100 generates a combination of modulation schemes and uses the generated combination for communication. In the third embodiment, an example will be described in which the base station 100 generates a plurality of combinations of modulation schemes for a plurality of terminals and uses the generated combinations for communication.

[0052] A wireless communication system 2 according to a third embodiment will be described with reference to FIG. 9 . FIG. 9 is a diagram illustrating an example of the wireless communication system 2 according to the third embodiment. The wireless communication system 2 includes a base station 100, a terminal 200A, a terminal 200B, a server 300, and a core network 400. The base station 100 forms a cell C10, and the terminals 200A and 200B are present in the cell C10. The base station 100 can communicate with the terminal 200 in the cell C10. The base station 100 can also communicate with the server 300 via the core network 400. The base station 100, the server 300, and the core network 400 are similar to those in the wireless communication system 1 illustrated in FIG. 1 , and therefore are denoted by the same reference numerals and will not be described again. The configurations of the terminals 200A and 200B are the same as those of the terminal 200 illustrated in FIG. 3 . Hereinafter, the functional blocks of terminal 200A will be described as a transmitting unit 210A, a receiving unit 220A, a control unit 230A, and a memory unit 240A, and the functional blocks of terminal 200B will be described as a transmitting unit 210B, a receiving unit 220B, a control unit 230B, and a memory unit 240B.

[0053] A method for generating a plurality of combinations of modulation schemes for a plurality of frequency bands and indexes corresponding to the combinations in accordance with information on communication quality from a plurality of terminals and notifying the plurality of terminals of the combinations will be described with reference to Fig. 10. Fig. 10 is a diagram showing an example of a sequence of a wireless communication system 2 according to the third embodiment.

[0054] Transmitter 210A of terminal 200A measures the quality of communication between terminal 200A and base station 100, and transmits information related to the measurement result to base station 100 (step S40). Transmitter 210B of terminal 200B measures the quality of communication between terminal 200B and base station 100, and transmits information related to the measurement result to base station 100 (step S41). Measurement of communication quality includes, for example, measurement of CSI-RS or SSB, as in the first embodiment.

[0055] The control unit 130 of the base station 100 generates a plurality of combinations of modulation schemes for a plurality of frequency bands and indexes corresponding to the combinations, based on information relating to the measurement results received by the receiving unit 120 of the base station 100 from the terminal 200A and the terminal 200B (step S42). The transmitting unit 110 of the base station 100 transmits information relating to the generated plurality of combinations and the indexes corresponding to each combination to the terminal 200A and the terminal 200B (steps S43 and S44). Alternatively, the transmitting unit 110 of the base station 100 multicasts information relating to the generated plurality of combinations and the indexes corresponding to each combination (steps S43 and S44).

[0056] An example of generating a plurality of combinations of modulation methods for a plurality of frequency bands and indexes corresponding to the combinations in step S42 will be described.

[0057] The control unit 130 of the base station 100 determines the modulation method for each frequency band for the multiple terminals based on information about the measurement results received from the terminals 200A and 200B. Here, as in the second embodiment, it is considered to use a modulation method that can transmit a large number of bits at one time in frequency bands with high communication quality, and to use a modulation method that is less susceptible to the effects of noise and interference in frequency bands with low communication quality.

[0058] It is also possible to determine the modulation scheme for each frequency band for multiple terminals by referring to other values ​​instead of information related to the measurement results from terminal 200A and terminal 200B. For example, the modulation scheme for each frequency band may be determined based on at least one of the transmission characteristics of base station 100 and the propagation loss of the propagation path. In this case, steps S40 and S41 in Fig. 10 are not necessary.

[0059] Here, similarly to the second embodiment, the control unit 130 of the base station 100 can also determine the bandwidth for each frequency band. The bandwidth of the frequency band may be a bandwidth set in advance, or may be determined based on measurement results from the terminals 200A and 200B. If the bandwidth of the frequency band is set in advance, the transmission unit 110 of the base station 100 transmits the modulation scheme corresponding to each of the multiple frequency bands in steps S43 and S44. If the bandwidth is determined based on measurement results from the terminals 200A and 200B, the transmission unit 110 of the base station 100 transmits the bandwidth for each of the multiple frequency bands and the corresponding modulation scheme in steps S43 and S44.

[0060] After transmitting or multicasting the generated multiple combinations and the indexes corresponding to each combination to terminal 200A and terminal 200B, base station 100 can transmit signals to terminal 200A and terminal 200B or multicast signals to terminal 200A and terminal 200B in the same manner as the sequences of FIG. 5 and FIG. 7 in the first embodiment. Terminal 200A and terminal 200B can also transmit signals to base station 100 in the same manner as FIG. 6 in the first embodiment. Control unit 130 of base station 100 can also determine a combination to be used for communication for each terminal. Control unit 130 of base station 100 can also determine a combination to be used for communication common to multiple terminals.

[0061] When determining the combination to be used for communication for each terminal, the control unit 130 of the base station 100 selects the combination to be used for communication from among multiple combinations, and the transmission unit 110 of the base station 100 transmits an index corresponding to the combination to be used for communication to the terminal 200A or the terminal 200B.

[0062] When determining a combination to be used for communication common to multiple terminals, the control unit 130 of the base station 100 selects a combination to be used for communication from multiple combinations, and the transmission unit 110 of the base station 100 transmits or multicasts an index corresponding to the combination to be used for communication to the terminal 200A and the terminal 200B.

[0063] By controlling in this way, it is possible to determine the modulation method for each of the multiple frequency bands into which the band is divided, and it is also possible to reduce the number of signals or the amount of information compared to when using multiple frequency bands separately.

[0064] As described above, in the third embodiment, the base station 100 generates a plurality of combinations of modulation schemes for a plurality of frequency bands that are common to the terminals 200A and 200B. By controlling in this manner, it is possible to appropriately control the modulation scheme for each frequency band, for example, when performing communication over a wide bandwidth. Furthermore, as in the first embodiment, the combination of modulation schemes for each frequency band is notified using an index. By controlling in this manner, it is possible to perform modulation schemes for each of a plurality of frequencies within a band with a small number of signals. Furthermore, for example, when performing communication over a wide bandwidth using radio waves in a high frequency band, it is possible to appropriately control the modulation scheme for signals while suppressing an increase in the number of signals or the amount of information. Hardware configuration of each device in each embodiment

[0065] The hardware configuration of each device in the wireless communication system of each embodiment will be described with reference to FIGS.

[0066] Fig. 11 is a diagram showing an example of the hardware configuration of the base station 100. As shown in Fig. 11, the base station 100 has, as hardware components, for example, a radio frequency (RF) circuit 520 including an antenna 510, a central processing unit (CPU) 530, a memory 540, a digital signal processor (DSP) 550, and a network interface (IF) 560. The antenna 510 transmits and receives signals when communicating with the terminal 200. The RF circuit 520 performs processing such as signal conversion between the antenna 510 and the CPU 530. The CPU 530 processes data and controls other components. The memory 540 includes at least one of a RAM (Random Access Memory) such as an SDRAM (Synchronous Dynamic Random Access Memory), a ROM (Read Only Memory), and a flash memory, and stores programs, control information, and data signals. The DSP 550 performs arithmetic operations on data for filtering, analysis, and transmission. The network IF 560 is connected when communicating with the terminal 200, other base stations, and a core network.

[0067] The correspondence between the functional block configuration of base station 100 shown in Fig. 2 and the hardware configuration of base station 100 shown in Fig. 10 will be described. The transmitter 110 and receiver 120 are realized by an antenna 510, an RF circuit 520, and a network IF 560. The controller 130 is realized by a CPU 530 and a DSP 550. The storage unit 140 is realized by a memory 540.

[0068] Fig. 12 is a diagram showing an example of the hardware configuration of terminal 200. As shown in Fig. 12, terminal 200 has, as hardware components, for example, an RF circuit 620 equipped with an antenna 610, a CPU 630, and a memory 640. Antenna 610 transmits and receives signals when communicating with base station 100. RF circuit 620 performs processing such as signal conversion between antenna 610 and CPU 630. CPU 630 processes data and controls other components. Memory 640 stores programs, control information, and data signals.

[0069] The correspondence between the functional block configuration of terminal 200 shown in Fig. 3 and the hardware configuration of terminal 200 shown in Fig. 12 will be described. Transmitting unit 210 and receiving unit 220 are realized by antenna 610 and RF circuit 620. Control unit 230 is realized by CPU 630. Storage unit 240 is realized by memory 640.

[0070] In each embodiment, examples of a base station, a communication device, and a terminal are described, but the disclosed technology is not limited to these, and can be applied to various devices, such as electronic devices mounted on automobiles, trains, airplanes, and artificial satellites, electronic devices transported by drones, etc., robots, AV equipment, home appliances, office equipment, vending machines, and other household equipment.

[0071] Furthermore, although the embodiments have been described using fifth-generation mobile communications as an example, the application of the disclosed technology is not limited to this. For example, the disclosed technology may be applied to mobile communications of different generations, such as sixth and seventh generations.

[0072] 1, 2 Wireless communication system 100 Base station 200 Terminal 300 Server 400 Core network C10 Cell 110 Transmitter 120 Receiver 130 Control unit 140 Memory unit 210 Transmitter 220 Receiver 230 Control unit 240 Memory unit 200A Terminal 200B Terminal 210A Transmitter 220A Receiver 230A Control unit 240A Memory unit 210B Transmitter 220B Receiver 230B Control unit 240B Memory unit 510 Antenna 520 RF circuit 530 CPU 540 Memory 550 DSP 560 Network IF 610 Antenna 620 RF circuit 630 CPU 640 Memory

Claims

1. A wireless communication device comprising: a control unit that selects a first index from a plurality of indexes; and a transmission unit that transmits the first index to a first wireless communication device, wherein the first index indicates that a first frequency band corresponds to a first modulation method and a second frequency band corresponds to a second modulation method.

2. The wireless communication device according to claim 1, wherein the first modulation method and the second modulation method are different modulation methods.

3. The wireless communication device according to claim 1, characterized in that the transmitter transmits the first index to a second wireless communication device different from the first wireless communication device.

4. The wireless communication device described in claim 1, characterized in that the control unit modulates a first signal using a modulation method for each frequency band indicated by the first index, and the transmission unit transmits the first signal modulated by the control unit to the first wireless communication device.

5. The wireless communication device according to claim 1, characterized in that the wireless communication device has a receiving unit that receives a second signal from the first wireless communication device, and the control unit causes the receiving unit to demodulate the second signal in accordance with a modulation method for each frequency band indicated by the first index.

6. The wireless communication device according to claim 1, characterized in that the wireless communication device has a receiving unit that receives a third signal from the first wireless communication device, the third signal having first information regarding the quality of communication between the wireless communication device and the first wireless communication device, and the first index is selected in accordance with the first information.

7. The wireless communication device described in claim 1, characterized in that the control unit generates a first combination indicated by the first index and a second combination indicated by a second index from among the multiple indexes, wherein the first combination is such that the first frequency band corresponds to the first modulation method and the second frequency band corresponds to the second modulation method, and the second combination is such that the first frequency band corresponds to a third modulation method and the second frequency band corresponds to a fourth modulation method.

8. The wireless communication device according to claim 7, characterized in that the control unit generates the first combination and the second combination depending on the transmission characteristics of the wireless communication device and the propagation loss of the propagation path.

9. The wireless communication device according to claim 7, characterized in that the control unit generates the first combination and the second combination depending on the reception characteristics of the wireless communication device and the propagation loss of the propagation path.

10. The wireless communication device according to claim 7, characterized in that the wireless communication device has a receiving unit that receives a third signal from the first wireless communication device and a fourth signal from the second wireless communication device, the third signal having first information regarding the quality of communication between the wireless communication device and the first wireless communication device, and the fourth signal having second information regarding the quality of communication between the wireless communication device and the second wireless communication device, and the control unit generates the first combination and the second combination depending on the first information and the second information.

11. The wireless communication device according to claim 10, characterized in that the transmitting unit transmits information regarding the first combination and the second combination to the second wireless communication device different from the first wireless communication device.

12. A wireless communication device comprising: a storage unit that stores a plurality of indexes; and a receiving unit that receives a first index from a first wireless communication device, wherein the first index indicates that a first frequency band corresponds to a first modulation method and a second frequency band corresponds to a second modulation method.

13. A wireless communication system comprising: a first wireless communication device that selects a first index from a plurality of indexes and transmits the first index; and a second wireless communication device that receives the first index, wherein the first index indicates that a first frequency band corresponds to a first modulation method and a second frequency band corresponds to a second modulation method.

Images