Communication device, and communication method

Abstract

To provide a communication device capable of improving wireless communication performance.SOLUTION: The communication device includes: a receiving circuit that receives information regarding at least one of a first center frequency of a first frequency band at which a transmitter transmits a signal and a second center frequency of a second frequency band at which a receiver receives a signal; and a control circuit that controls transmission in the first frequency band or reception in the second frequency band based on the information.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a communication device and a communication method. [Background technology]

[0002] Cellular wireless communications, including 5G NR (New Radio access technology), are currently underway. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Kosuke Yamazaki, Takeo Ozeki, Yoshiaki Amano, Takahide Murakami, Hiroyuki Shinbo, and Yoji Kishi, "PROPOSAL FOR A USER-CENTRIC RAN ARCHITECTURE TOWARDS BEYOND 5G," IEICE Technical Report, vol. 121, no. 189, SAT2021-43, pp. 4-10, October 2021. Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is room for improvement in how wireless communication performance can be improved.

[0005] Non-limiting embodiments of the present disclosure contribute to providing a communication device and a communication method that can improve the performance of wireless communication. [Means for solving the problem]

[0006] A communication device according to one embodiment of the present disclosure includes a receiving circuit that receives information regarding at least one of a first central frequency of a first frequency band at which a transmitter transmits a signal and a second central frequency of a second frequency band at which a receiver receives the signal, and a control circuit that controls transmission in the first frequency band or reception in the second frequency band based on the information.

[0007] 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. [Effects of the Invention]

[0008] According to an embodiment of the present disclosure, the performance of wireless communication can be improved.

[0009] Further advantages and benefits of certain aspects of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, but not necessarily all of them may be provided to obtain one or more identical features. [Brief explanation of the drawings]

[0010] [Figure 1] A diagram showing an example of transmission and reception processing divided into sub-bands. [Figure 2] Block diagram showing an example of the configuration of a portion of a base station [Figure 3] Block diagram showing an example of the configuration of a part of a terminal [Figure 4] Block diagram showing an example of the configuration of a base station [Figure 5] Block diagram showing an example of a terminal configuration DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0012] Microwave and millimeter wave band radio waves are used in cellular wireless communications including 5G NR. In 6G systems (sixth generation mobile communication systems), the use of terahertz (or sub-terahertz) band radio waves above 100 GHz is also being considered. For example, Non-Patent Document 1 proposes a system that uses terahertz waves for communication near terminals.

[0013] In the terahertz band, it is expected that wireless signals will be transmitted and received using a wide RF (Radio Frequency) frequency bandwidth.

[0014] For example, due to limitations in the transmission circuit, a transmitter may generate signals by dividing the RF frequency band for transmitting signals into multiple frequency bands (hereinafter referred to as "subbands" or, for example, referred to as transmission subbands). In this case, LO (Local Oscillator) leakage (e.g., interference due to contamination by a local oscillator signal) may occur at the center frequency (e.g., referred to as the transmission center frequency) of each transmission subband, which may degrade the reception performance of those frequencies.

[0015] Furthermore, for example, a receiver may divide an RF frequency band for receiving signals into multiple subbands (also referred to as reception subbands) and perform signal reception processing. In this case, due to the influence of a DC (direct current) offset or the like of a receiving circuit corresponding to each reception subband, reception performance may be degraded near the DC of the signal after down-converting the RF signal of each subband (for example, near the center frequency of each reception subband (also referred to as reception center frequency)).

[0016] FIG. 1 shows an example of a process for dividing an RF frequency band into sub-bands on both the transmitting and receiving sides.

[0017] In the example of FIG. 1, the transmitter generates two 2.4 GHz-bandwidth RF signals (transmission RF signals) in parallel. The total bandwidth of the RF signals in the two sub-bands (transmission sub-bands) is 4.8 GHz. That is, the transmitter generates a 4.8 GHz-bandwidth signal by dividing it into two sub-bands. Also, in the example of FIG. 1, the receiver divides the received 4.8 GHz-bandwidth RF signal (reception RF signal) into three 1.6 GHz-bandwidth sub-bands (reception sub-bands) and receives and processes the RF signals corresponding to each sub-band in parallel.

[0018] Note that whether or not a frequency band is divided into subbands and the method for doing so may depend on the implementation of the transmitter and receiver. Figure 1 shows an example of a subband division method, and the number of subbands is not limited to the example in Figure 1. For example, the number of subbands may be the same between a transmitter and a receiver, or may be different. Also, the number of subbands may be one (i.e., no subband division may be performed).

[0019] As described above, the reception quality of frequency resources (e.g., subcarriers) corresponding to the center frequency of each subband of the transmitted RF signal may be degraded due to the influence of LO leakage, etc. Furthermore, the reception quality of subcarriers corresponding to the center frequency of each subband of the received RF signal may be degraded due to the influence of DC offset, etc.

[0020] Generally, channel estimates are interpolated or averaged among neighboring subcarriers, so the degradation of reception quality at the center frequency also affects neighboring subcarriers of the center frequency. Therefore, processing to improve reception quality at the center frequency is expected.

[0021] As mentioned above, whether or not to divide a frequency band into subbands and how to do so may depend on the implementation of the transmitter and receiver. For example, if the transmitter and receiver do not know each other's center frequencies, they may not be able to perform processing to improve reception quality at the center frequencies. There has been insufficient discussion about how to share information about the center frequencies of each transmitter and receiver between the transmitter and receiver.

[0022] In a non-limiting embodiment of the present disclosure, a method for improving reception quality according to the center frequency of each subband of a transmitter / receiver will be described. For example, communication devices such as a transmitter and a receiver transmit or receive signals while avoiding at least one of the center frequency (transmission center frequency) of the frequency band used by the transmitter for transmission (signal generation) and the center frequency (reception center frequency) of the frequency band used by the receiver for reception.

[0023] [Communication System Overview] A communication system according to one embodiment of the present disclosure includes at least one base station 100 (or gNB, access point) and a terminal 200 (or mobile station, user terminal, UE (User Equipment), STA (Station)).

[0024] In the following, an example of data transmission from base station 100 to terminal 200 (i.e., data transmission in downlink) will be described as an example. However, this is not limited to downlink, and may be applied to, for example, uplink data transmission (data transfer) from terminal 200 to base station 100.

[0025] 2 is a block diagram showing an example of the configuration of a portion of a base station 100 (e.g., corresponding to a communication device). In the base station 100 shown in FIG. 2, a communication unit (e.g., corresponding to a receiving circuit) receives information regarding at least one of a first central frequency of a first frequency band at which a transmitter (the base station 100 in the downlink and the terminal 200 in the uplink) transmits a signal and a second central frequency of a second frequency band at which a receiver (the terminal 200 in the downlink and the base station 100 in the uplink) receives a signal. A control unit (e.g., corresponding to a control circuit) controls transmission in the first frequency band or reception in the second frequency band based on the information.

[0026] 3 is a block diagram showing an example of the configuration of a portion of terminal 200 (e.g., corresponding to a communication device). In terminal 200 shown in FIG. 3, a communication unit (e.g., corresponding to a receiving circuit) receives information on at least one of a first central frequency of a first frequency band at which a transmitter (base station 100 in the downlink and terminal 200 in the uplink) transmits a signal and a second central frequency of a second frequency band at which a receiver (terminal 200 in the downlink and base station 100 in the uplink) receives a signal. A control unit (e.g., corresponding to a control circuit) controls transmission in the first frequency band or reception in the second frequency band based on the information.

[0027] [Base station configuration example] FIG. 4 is a block diagram showing an example of the configuration of base station 100 according to this embodiment.

[0028] 4, a transmitting side baseband processing unit 102 to a BPF (Band Pass Filter) 107 constitute a "transmitting unit" that performs transmission processing of signals. The base station 100 also includes a control unit 101 that controls the transmission processing of the transmitting unit.

[0029] 4 may include subband processing systems corresponding to a plurality of subbands (e.g., n subbands). Each subband processing system may include, for example, a transmitting baseband processing unit 102, a DA conversion unit 103, an LPF (Low Pass Filter) 104, an LO 105, an up-converter (UPC) 106, and a BPF 107.

[0030] Base station 100 also includes a "receiving unit" that performs signal reception processing. The receiving unit may include, for example, a receiving-side RF processing unit that processes a received RF signal, and a receiving-side baseband processing unit that performs baseband processing on a signal after the receiving RF processing (a signal from terminal 200). Note that in base station 100, the receiving unit may receive a signal by dividing it into multiple subbands, similar to the transmitting unit. For example, the receiving unit may include a subband processing system corresponding to multiple subbands.

[0031] In FIG. 4, each component (circuit) is shown divided into processing systems for each subband, but the circuit configuration is not limited to this. For example, the transmitting side baseband processing unit 102, the DA conversion unit 103, the LPF 104, and some or all of the other circuit units may be shared between subbands.

[0032] Also, for example, at least one of the control unit 101 and the transmitting-side baseband processing unit 102 shown in Fig. 4 may be included in the control unit shown in Fig. 2. Also, at least one of the DA conversion units 103 to BPF 107 shown in Fig. 4 may be included in the communication unit shown in Fig. 2.

[0033] 4, information received from terminal 200 is input to control unit 101 from a receiving unit (for example, a receiving-side baseband processing unit). The information from terminal 200 may include, for example, information related to the receiving central frequency of a receiving subband in terminal 200. For example, based on the information from terminal 200, control unit 101 determines resources to which data is to be mapped, and instructs each transmitting-side baseband processing unit 102 (for example, a resource mapping unit 123 described later) to perform resource mapping. Furthermore, control unit 101 instructs each transmitting-side baseband processing unit 102 (for example, a control information generating unit 121 described later) to generate control information.

[0034] Each transmitting-side baseband processing unit 102 performs baseband processing on transmission data in accordance with instructions from the control unit 101. The transmitting-side baseband processing unit 102 may include, for example, a control information generating unit 121, an encoding / modulating unit 122, and a resource mapping unit 123.

[0035] The control information generating unit 121 generates control information in accordance with an instruction from the control unit 101, and outputs the control information to at least one of the coding and modulation unit 122 and the resource mapping unit 123. The control information may include, for example, information regarding the transmission center frequency of the corresponding subband.

[0036] The coding and modulation unit 122 performs coding and modulation on the transmission data and control information input from the control information generation unit 121 , for example, and outputs the modulated signal to the resource mapping unit 123 .

[0037] The resource mapping unit 123 maps the signal input from the coding and modulation unit 122 and the control information input from the control information generation unit 121 to radio resources, for example, in accordance with a resource mapping instruction from the control unit 101, and outputs the mapped signal to the DA conversion unit 103. For example, the resource mapping unit 123 may map the signal to a resource of a subband corresponding to the transmitting-side baseband processing unit 102.

[0038] The DA conversion unit 103 converts, for example, a baseband signal (digital signal) input from the transmitting-side baseband processing unit 102 (for example, the resource mapping unit 123 ) into an analog signal, and outputs the analog signal to the LPF 104 .

[0039] The LPF 104 performs processing to remove frequency components above a certain frequency band (or processing to pass desired low-frequency components) from the analog signal input from the DA conversion unit 103, for example, and outputs the signal to the UPC .

[0040] The LO 105 generates an LO signal and outputs it to the UPC 106. Here, the frequency of the LO signal differs for each subband.

[0041] The UPC 106 uses the LO signal input from the LO 105 to up-convert the frequency of the signal input from the LPF 104 to a transmission frequency, and outputs the up-converted signal to the BPF 107 .

[0042] The BPF 107 performs processing to remove frequency components outside a specific band (or processing to pass specific band components) from the signal input from the UPC 106, and outputs an RF signal. Here, the specific band differs for each subband.

[0043] [Device configuration example] FIG. 5 is a block diagram showing an example of the configuration of terminal 200 according to this embodiment.

[0044] 5, BPF 201 to receiving-side baseband processing section 206 constitute a "receiving section" that performs signal receiving processing. Terminal 200 also includes control section 207 that controls the receiving processing for the receiving section.

[0045] 5 may include subband processing systems corresponding to a plurality of subbands (e.g., m subbands). Each subband processing system may include, for example, a BPF 201, an LO 202, a down-converter (DNC) 203, an LPF 204, an AD conversion unit 205, and a receiving-side baseband processing unit 206.

[0046] Terminal 200 also includes a "transmitter" that performs transmission processing of a signal. The transmitter may include, for example, a transmitter baseband processor that performs baseband processing on a signal including transmission data or control information (information to be notified to base station 100), and a transmitter RF processor that performs transmission RF processing on the signal after baseband processing. The control information may include, for example, information related to the reception center frequency of a reception subband in terminal 200 (for example, information related to the center frequency, or information related to a reception signal at the center frequency).

[0047] Note that, in terminal 200, the transmitter may generate signals by dividing into multiple subbands, similar to the receiver. For example, the transmitter may include subband processing systems corresponding to multiple subbands.

[0048] In FIG. 5, each component (circuit) is shown divided into processing systems for each subband, but the circuit configuration is not limited to this. For example, the receiving side baseband processing unit 206, the AD conversion unit 205, the LPF 204, and some or all of the other circuit units may be shared between subbands.

[0049] Also, for example, at least one of the receiving-side baseband processing unit 206 and the control unit 207 shown in Fig. 5 may be included in the control unit shown in Fig. 3. Also, at least one of the BPF 201 to the AD conversion unit 205 shown in Fig. 5 may be included in the communication unit shown in Fig. 3, for example.

[0050] 5, BPF 201 performs processing to remove frequency components outside a specific band from the received RF signal (or processing to extract specific frequency band components), and outputs the processed signal to DNC 203. Here, the extracted frequency band differs for each subband.

[0051] The LO 202 generates an LO signal and outputs it to the DNC 203. Here, the frequency of the LO signal differs for each subband.

[0052] The DNC 203 down-converts the signal input from the BPF 201 using the LO signal input from the LO 202 , and outputs the result to the LPF 204 .

[0053] The LPF 204 performs processing to remove frequency components above a certain frequency band (or processing to pass desired low-frequency components) from the analog signal input from the DNC 203 , for example, and outputs the signal to the AD conversion unit 205 .

[0054] The AD conversion unit 205 converts, for example, the analog signal input from the LPF 204 into a baseband signal (digital signal), and outputs the baseband signal to the receiving-side baseband processing unit 206 (for example, the resource demapping unit 261).

[0055] Each receiving baseband processing unit 206 performs baseband processing on a received signal from the base station 100 (a signal input from the AD conversion unit 205) in accordance with an instruction from the control unit 207. The receiving baseband processing unit 206 may include, for example, a resource demapping unit 261, a demodulation and decoding unit 262, and a control information detection unit 263.

[0056] The resource demapping unit 261 extracts a data signal and a control signal from the signal input from the AD conversion unit 205 in accordance with a resource demapping instruction from the control unit 207. The resource demapping unit 261 outputs the extracted data signal to the demodulation and decoding unit 262 and outputs the control signal to the control information detection unit 263. For example, the resource demapping unit 261 may extract a signal of a resource of a subband corresponding to the receiving-side baseband processing unit 206.

[0057] The demodulation and decoding unit 262 demodulates and decodes the data signal input from the resource demapping unit 261, and extracts received data and control information. The demodulation and decoding unit 262 outputs the extracted control information to the control unit 207.

[0058] The control information detector 263 extracts control information from the control signal input from the resource demapping unit 261 and outputs the control information to the controller 207. The control information may include, for example, information regarding the transmission central frequency of the transmission subband in the base station 100.

[0059] The control unit 207 determines a resource demapping method based on control information input from the receiving-side baseband processing unit 206 (for example, the demodulation and decoding unit 262 or the control information detection unit 263), and instructs the determined method to the resource demapping unit 261. The control unit 207 also determines information to be notified to the base station 100, and outputs the notified information to a transmitting unit (for example, the transmitting-side baseband processing unit).

[0060] [Example of Operation of Base Station 100 and Terminal 200] Next, an example of the operation of base station 100 and terminal 200 will be described.

[0061] Operation examples 1 and 2 will be explained below.

[0062] [Example 1] In operation example 1, base station 100 and terminal 200 do not transmit or receive signals in frequency resources (e.g., subcarriers) corresponding to at least one of the transmission central frequency and the reception central frequency. For example, base station 100 and terminal 200 transmit or receive signals in frequency resources different from the frequency resources (e.g., subcarriers) corresponding to at least one of the transmission central frequency and the reception central frequency.

[0063] <Example of operation 1-1> In operation example 1-1, terminal 200 on the receiving side notifies base station 100 on the transmitting side of information relating to the receiving center frequency of each receiving subband.

[0064] Base station 100 does not map a signal (e.g., data or RS (Reference Signal)) to a frequency resource (e.g., subcarrier) corresponding to the reception central frequency notified by terminal 200. For example, base station 100 maps data or RS to a frequency resource different from the frequency resource corresponding to the reception central frequency notified by terminal 200. In this way, base station 100 (e.g., transmitter) receives information about the reception central frequency from terminal 200 (receiver) and controls signal transmission in a frequency resource different from the reception central frequency.

[0065] An example of the operation of base station 100 and terminal 200 in operation example 1-1 will be described below.

[0066] (ST101) Terminal 200 notifies base station 100 of information related to the reception central frequency of each reception subband of terminal 200. A signal used to notify the information related to the reception central frequency may be, for example, an uplink physical layer signal (e.g., UCI: Uplink Control Information, CSI: Channel State Information), a higher layer signal (e.g., RRC: Radio Resource Control, MAC: Media Access Control), or another signal. Furthermore, a resource used to notify the information related to the reception central frequency may be, for example, a PRACH (Physical Random Access CHannel), a PUCCH (Physical Uplink Control CHannel), a PUSCH (Physical Uplink Shared CHannel), or another channel.

[0067] (ST102) Base station 100 identifies the center frequency of each reception subband at terminal 200 based on the signal received from terminal 200 .

[0068] (ST103) Base station 100 maps the downlink data signal and RS for terminal 200 to a frequency resource (e.g., a subcarrier) other than the frequency resource corresponding to the reception central frequency (or near the reception central frequency) identified in the processing of (ST102), and transmits the signal and RS to terminal 200.

[0069] (ST104) The terminal 200 receives a data signal and an RS from the base station 100 .

[0070] As described above, terminal 200 notifies base station 100 of information related to the reception central frequency of terminal 200, and base station 100 transmits data without using frequency resources near the reception central frequency of terminal 200. As a result, even if the transmission subband configuration and the reception subband configuration are different, as shown in FIG. 1, for example, base station 100 identifies frequency resources near the reception central frequency of terminal 200 and transmits signals avoiding these frequency resources, which allows terminal 200 to receive data while reducing the influence of DC offset and the like that may occur near the reception central frequency, for example, thereby improving reception quality.

[0071] Although the above has described downlink data transmission, operation example 1-1 may also be applied to uplink data transmission. For example, in the process of (ST103), base station 100, which is the uplink receiving side, may transmit a grant signal (including, for example, information capable of identifying a reception central frequency) for scheduling uplink data transmission to terminal 200, which is the uplink transmitting side. Also, for example, in the process of (ST104), terminal 200 may transmit an uplink data signal and an RS based on the grant signal. In this case, terminal 200 may map the uplink data signal and the RS to a frequency resource different from the frequency resource corresponding to the reception central frequency (or near the reception central frequency) of each reception subband of base station 100.

[0072] <Example of operation 1-2> In operation example 1-2, base station 100 on the transmitting side notifies terminal 200 on the receiving side of information relating to the transmission center frequency of each transmission subband.

[0073] Terminal 200 does not use frequency resources (e.g., subcarriers) corresponding to the transmission central frequency notified by base station 100 for reception processing (e.g., channel estimation, etc.). For example, terminal 200 uses frequency resources different from the frequency resources corresponding to the transmission central frequency for reception processing. In this way, terminal 200 (e.g., receiver) receives information regarding the transmission central frequency from base station 100 (transmitter) and controls signal reception in frequency resources different from the transmission central frequency.

[0074] Hereinafter, an operation example of the base station 100 and the terminal 200 in the operation example 1-2 will be described.

[0075] (ST201) Base station 100 notifies terminal 200 of information related to the transmission central frequency of each transmission subband of base station 100. A signal used to notify the information related to the transmission central frequency may be, for example, a downlink physical layer signal (e.g., DCI: Downlink Control Information), a higher layer signal, or another signal. Furthermore, a resource used to notify the information related to the transmission central frequency may be a PDCCH (Physical Downlink Control CHannel), a PDSCH (Physical Downlink Shared CHannel), or another channel.

[0076] (ST202) Base station 100 maps the downlink data signal and RS for terminal 200 to a frequency resource (e.g., a subcarrier) other than the frequency resource corresponding to the transmission center frequency (or near the transmission center frequency) of each transmission subband of base station 100, and transmits the signal to terminal 200.

[0077] (ST203) Terminal 200 receives a data signal and an RS from base station 100. At this time, terminal 200 performs reception processing (e.g., channel estimation) without using frequency resources (e.g., subcarriers) corresponding to the transmission central frequency (or near the transmission central frequency) notified in the processing of (ST201).

[0078] As described above, base station 100 notifies terminal 200 of information related to the transmission central frequency of base station 100, and terminal 200 receives data without using frequency resources near the transmission central frequency of base station 100. As a result, even if the transmission subband configuration and the reception subband configuration are different, for example, as shown in Fig. 1, the terminal identifies frequency resources near the transmission central frequency of base station 100 and receives signals while avoiding these frequency resources, thereby reducing the effects of LO leakage or DC offset that may occur near the transmission central frequency and allowing data to be received, thereby improving reception quality.

[0079] Although the above has described downlink data transmission, operation example 1-2 may also be applied to uplink data transmission. For example, in the process of (ST202), base station 100, which is the uplink receiving side, may transmit a grant signal for scheduling uplink data transmission to terminal 200. Also, for example, in the process of (ST203), terminal 200 may transmit an uplink data signal and an RS based on the grant signal. At this time, terminal 200 may notify base station 100 of information related to the transmission central frequency of the transmission subband of terminal 200. Base station 100 may perform reception processing without using frequency resources corresponding to the transmission central frequency (or near the transmission central frequency) of each transmission subband of terminal 200.

[0080] <Combination of Operation Example 1-1 and Operation Example 1-2> For example, in operation example 1-1, information on the reception central frequency may be reported from terminal 200 to base station 100, and information on the transmission central frequency may be reported from base station 100 to terminal 200. In this case, in the process of (ST103), base station 100 may map the data signal and RS to a frequency resource different from the frequency resource corresponding to both the reception central frequency and the transmission central frequency. Furthermore, terminal 200 may perform reception processing without using the frequency resource corresponding to both the transmission central frequency and the reception central frequency. Note that this is not limited to downlink transmission, and similarly, in the case of uplink transmission, information on the reception central frequency may be reported from base station 100 to terminal 200, and information on the transmission central frequency may be reported from terminal 200 to base station 100.

[0081] Furthermore, in operation example 1-2, information regarding the transmission central frequency may be reported from base station 100 to terminal 200, and information regarding the reception central frequency may be reported from terminal 200 to base station 100. In this case, in the process of (ST202), base station 100 may map the data signal and RS to a frequency resource different from the frequency resource corresponding to both the transmission central frequency and the reception central frequency. Furthermore, terminal 200 may perform reception processing without using the frequency resource corresponding to both the transmission central frequency and the reception central frequency. Note that information regarding the reception central frequency may be reported from base station 100 to terminal 200 not only in downlink transmission but also in uplink transmission.

[0082] <Information about frequency resources to be notified> In the first operation example, the information notified as the frequency resource corresponding to the center frequency may be, for example, a subcarrier index, an RB (Resource Block) index, or an index representing another frequency unit. Alternatively, for example, a subband division method may be notified instead of the information regarding the frequency resource. This may result in the center frequency being implicitly notified.

[0083] <Notification of inter-subband guard band resources> In the first operational example, information regarding resources of guard bands between transmission subbands may be notified from the transmitting side to the receiving side. Also, information regarding resources of guard bands between reception subbands may be notified from the receiving side to the transmitting side. This makes it possible to prevent degradation of reception quality due to the guard bands. Also, for example, base station 100 and terminal 200 may identify the subband division (or subband configuration) of the communication partner based on information regarding the guard band resources of the communication partner, and identify the center frequency of each subband. That is, the center frequency may be implicitly notified by the information regarding the guard band resources.

[0084] [Example 2] In the second operational example, the receiver notifies (or feeds back) to the transmitter information about a received signal at (or near) the transmission central frequency of the transmitter. The transmitter corrects its transmission circuit based on the information about the received signal notified by the receiver.

[0085] For example, in downlink transmission, terminal 200 on the receiving side notifies base station 100 on the transmitting side of information about received signals near the transmission center frequency of each transmission subband of base station 100. Base station 100 corrects its transmission circuit based on the notified information about the received signals.

[0086] An example of the operation of base station 100 and terminal 200 in operation example 2 will be described below.

[0087] (ST301) Base station 100 notifies terminal 200 of information related to the transmission central frequency of each transmission subband of base station 100. The signal used to notify the information related to the transmission central frequency may be, for example, a downlink physical layer signal, a higher layer signal, or another signal. Furthermore, the resource used to notify the information related to the transmission central frequency may be, for example, a PDCCH, a PDSCH, or another channel.

[0088] (ST302) Base station 100 transmits a data signal and an RS to terminal 200. Terminal 200 receives the data signal and the RS from base station 100.

[0089] (ST303) Of the data signals received in the process of (ST302), terminal 200 notifies (feeds back) information on the received signal at the transmission center frequency (e.g., subcarrier) notified in the process of (ST301) to base station 100. The information notified to base station 100 may include, for example, any of the following information or other information: Information indicating the reception quality (e.g., BLER (Block Error Rate) or SINR (Signal to Interference and Noise Ratio)) for the subcarrier (e.g., the degree of degradation of reception quality) Information about interference on the subcarrier (for example, the magnitude (absolute or relative value) of interference signals such as LO leakage) Information about the correction amount of the transmitter circuit (e.g., estimated DC offset in the transmitter circuit)

[0090] (ST304) Base station 100 corrects the transmission circuit based on the information received in the processing of (ST303). Correction of the transmission circuit may include, for example, correction processing to suppress LO leakage at the transmission center frequency, or correction processing to correct DC offset. Base station 100 then transmits a data signal or RS to terminal 200 using the corrected transmission circuit. At this time, base station 100 may map a signal to frequency resources corresponding to the transmission center frequencies of each transmission subband, and transmit the signal.

[0091] As described above, base station 100 transmits a data signal at the transmission central frequency of the corrected transmission circuit, and terminal 200 can receive the data signal while reducing the influence of LO leakage or DC offset that may occur near the transmission central frequency, thereby improving reception quality. Furthermore, according to Operation Example 2, data can be mapped near the transmission central frequency, and therefore resource utilization efficiency is improved compared to Operation Example 1.

[0092] Although the above describes downlink data transmission, operation example 2 may also be applied to uplink data transmission. For example, terminal 200, which is the uplink transmitter, may transmit information related to the transmission center frequency of a transmission subband to base station 100, which is the uplink receiver, and base station 100 may notify (feed back) information related to a received signal at the notified transmission center frequency (e.g., subcarrier) to terminal 200. Terminal 200 may correct its transmission circuit based on the received information.

[0093] As described above, in this embodiment, base station 100 and terminal 200 receive information regarding at least one of the transmitter's transmission central frequency and the receiver's reception central frequency, and control transmission in the transmission frequency band or reception in the reception frequency band based on the received information. As a result, even if, for example, whether or not a frequency band is divided into subbands and how that is done depends on the implementation of the transmitter and receiver, base station 100 and terminal 200 can identify the central frequency of the frequency band (e.g., subband) of the communication partner and control signal transmission and reception, thereby improving reception quality on the receiving side. Therefore, according to this embodiment, wireless communication performance can be improved.

[0094] The embodiments of the present disclosure have been described above.

[0095] In the above-described embodiment, if a subcarrier previously specified (or set) as a frequency resource for transmitting an RS overlaps (or collides) with a transmission central frequency or a reception central frequency, base station 100 or terminal 200 may stop transmitting the RS. Alternatively, base station 100 or terminal 200 may transmit the RS in a different frequency resource (i.e., shift the transmission subcarrier of the RS). Shifting the frequency resource for transmitting the RS does not reduce the number of received RSs, improving reception quality.

[0096] The radio frequency is also sometimes called the carrier frequency.

[0097] Although the microwave band, millimeter wave band, and terahertz band (or sub-terahertz band) have been described as examples of radio frequency bands, the present invention is not limited to these, and the frequency bands used for transmission or reception at base station 100 and terminal 200 may be other frequency bands or a combination of these frequency bands.

[0098] Furthermore, the notation "··· part" in the above-described embodiments may be replaced with other notations such as "··· circuitry," "··· device," "··· unit," or "··· module."

[0099] (control signal) In the above embodiment, the control signal may be a PDCCH that transmits DCI of the physical layer, or may be a higher layer signal (for example, MAC or RRC). Also, the above data signal may include a higher layer signal.

[0100] Furthermore, the PDCCH in the above operation example may be transmitted in a common search space or a UE specific search space.

[0101] (base station) In the above-described embodiments, the base station may be a TRP (Transmission Reception Point), a cluster head, an access point, an RRH (Remote Radio Head), an eNodeB (eNB), a gNodeB (gNB), a BS (Base Station), a BTS (Base Transceiver Station), a parent device, a gateway, etc. In addition, in sidelink communication, a terminal may act in place of a base station.

[0102] (uplink / downlink) Although the above embodiment has been described taking the downlink as an example, it can also be applied to the uplink PUSCH. For example, the PDCCH in the above operation example may be a PUCCH.

[0103] (Data channel / Control channel) In the above embodiments, the PDSCH or PUSCH resources may be allocated by the PDCCH or may be resources configured by a higher layer signal.

[0104] (reference signal) In the above embodiments, the reference signal (RS) is a signal known to both the base station and the mobile station, and may also be called an RS (Reference Signal) or a pilot signal. The reference signal may be a DMRS, a CSI-RS (Channel State Information - Reference Signal), a TRS (Tracking Reference Signal), a PTRS (Phase Tracking Reference Signal), an SRS (Sounding Reference Signal), or a CRS (Cell-specific Reference Signal).

[0105] (time interval) In the above embodiments, the unit of time resource is not limited to one or a combination of slots and symbols, but may be, for example, a time resource unit such as a frame, a superframe, a subframe, a slot, a time slot subslot, a minislot, or a symbol, an OFDM (Orthogonal Frequency Division Multiplexing) symbol, or an SC-FDMA (Single Carrier-Frequency Division Multiplexing) symbol, or another time resource unit. Furthermore, the number of symbols included in one slot is not limited to the number of symbols exemplified in the above embodiments, and may be another number of symbols.

[0106] (Applicable to side links) The above-described embodiment may also be applied to communication using a sidelink used for V2X (Vehicle to Everything) or terminal-to-terminal communication. In this case, the PDCCH may be a PSCCH (Physical Sidelink Control Channel), the PUSCH / PDSCH may be a PSSCH (Physical Sidelink Shared Channel), and the PUCCH may be a PSFCH (Physical Sidelink Feedback Channel).

[0107] (licensed band / unlicensed band) The above-described embodiments may also be applied to communications in licensed and unlicensed spectrum (unlicensed spectrum, shared spectrum). In the case of unlicensed spectrum, a channel access procedure (Listen Before Talk (LBT), carrier sense, Channel Clear Assessment (CCA)) may be performed before each signal transmission.

[0108] The present disclosure can be realized by software, hardware, or software linked to hardware. Each functional block used in the description of the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit, and each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data input and output. Depending on the degree of integration, the LSI may be called an IC, system LSI, super LSI, or ultra LSI.

[0109] The integrated circuit method is not limited to LSI, but may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, a field programmable gate array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI, may be used. The present disclosure may be realized as digital processing or analog processing.

[0110] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology can be used to integrate functional blocks. The application of biotechnology is also a possibility.

[0111] The present disclosure may be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) that has a communications function. The communications apparatus may include a wireless transceiver and processing / control circuitry. The wireless transceiver may include a receiver and a transmitter, or both functions. The wireless transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0112] Communications equipment is not limited to portable or mobile equipment, but also includes non-portable or fixed equipment, devices, and systems of any kind, such as smart home devices (such as appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0113] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0114] A communications device also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications device.

[0115] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0116] A communication device according to one embodiment of the present disclosure includes a receiving circuit that receives information regarding at least one of a first central frequency of a first frequency band at which a transmitter transmits a signal and a second central frequency of a second frequency band at which a receiver receives the signal, and a control circuit that controls transmission in the first frequency band or reception in the second frequency band based on the information.

[0117] In one embodiment of the present disclosure, the communication device is the transmitter, the receiving circuit receives information about the second central frequency from the receiver, and the control circuit controls transmission of the signal on a frequency resource different from the second central frequency.

[0118] In one embodiment of the present disclosure, the communication device is the receiver, the receiving circuit receives information about the first central frequency from the transmitter, and the control circuit controls reception of the signal on a frequency resource different from the first central frequency.

[0119] In one embodiment of the present disclosure, the communication device is the transmitter, the receiving circuit receives information about a received signal at the first central frequency from the receiver, and the control circuit corrects the transmitting circuit of the transmitter based on the information about the received signal.

[0120] In one embodiment of the present disclosure, the information about the received signal includes a reception quality at the first central frequency, a value indicating interference at the first central frequency, or a correction amount for the transmission circuit.

[0121] In a communication method according to one embodiment of the present disclosure, a communication device receives information regarding at least one of a first central frequency of a first frequency band at which a transmitter transmits a signal and a second central frequency of a second frequency band at which a receiver receives the signal, and controls transmission in the first frequency band or reception in the second frequency band based on the information. [Industrial Applicability]

[0122] One aspect of the present disclosure is useful in wireless communication systems. [Explanation of symbols]

[0123] 100 base stations 101,207 Control section 102 Transmitting side baseband processing unit 103 DA conversion section 104,204 LPF 105,202 LO 106 UPC 107,201 BPF 121 Control information generation unit 122 Encoding and Modulation Section 123 Resource Mapping Unit 203 DNC 205 AD conversion section 206 Receiving side baseband processing unit 261 Resource Demapping Unit 262 Demodulation and Decoding Unit 263 Control Information Detector

Claims

1. a receiver circuit for receiving information relating to at least one of a first center frequency of a first frequency band at which a transmitter transmits a signal and a second center frequency of a second frequency band at which a receiver receives the signal; a control circuit that controls transmission in the first frequency band or reception in the second frequency band based on the information; A communication device comprising:

2. the communication device is the transmitter, the receiving circuit receives information about the second center frequency from the receiver; the control circuit controls transmission of the signal on a frequency resource different from the second central frequency. The communication device according to claim 1 .

3. the communication device is the receiver, the receiving circuit receives information about the first center frequency from the transmitter; the control circuit controls reception of the signal on a frequency resource different from the first central frequency. The communication device according to claim 1 .

4. the communication device is the transmitter, the receiving circuit receives from the receiver information relating to a received signal at the first center frequency; the control circuit corrects a transmission circuit of the transmitter based on information about the received signal; The communication device according to claim 1 .

5. the information about the received signal includes a reception quality at the first central frequency, a value indicating interference at the first central frequency, or a correction amount of the transmission circuit; The communication device according to claim 4.

6. The communication device receiving information regarding at least one of a first center frequency of a first frequency band at which a transmitter transmits a signal and a second center frequency of a second frequency band at which a receiver receives the signal; controlling transmission in the first frequency band or reception in the second frequency band based on the information; Communication method.

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