Wireless communication device and wireless communication method

Abstract

This wireless communication device comprises: an extraction circuit (10) that extracts a clock signal from a transmission data signal which is 1-bit modulated and transmitted by a band-limited transmission system; and an arithmetic circuit (20) that executes an exclusive OR operation on the clock signal and the transmission data signal, and Manchester encodes the transmission data signal.

Description

Wireless communication device and wireless communication method

[0001] TECHNICAL FIELD The technology described herein relates to a wireless communication device and a wireless communication method.

[0002] A direct digital RF (Radio Frequency) wireless transmitter converts a 1-bit bandpass delta-sigma modulated signal into a rectangular wave, extracts a high-order image, and generates an RF transmission signal.

[0003] FIG. 1 is a block diagram showing a schematic configuration of an optical fiber transmission direct digital RF radio transmitter 6. As shown in FIG.

[0004] 1 includes a DSP (Digital Signal Processor) 61, multiple E / O (Electrical / Optical) converters 62, multiple O / E (Optical / Electrical) converters 63, multiple square wave circuits 64, multiple BPFs (Band Pass Filters) 65, multiple HPAs (High Power Amplifiers) 66, and multiple antennas 67. The O / E converters 63, square wave circuits 64, BPFs 65, and HPAs 66, which are enclosed by dashed lines, function as a transmission module per element.

[0005] The DSP 61 performs 1-bit delta-sigma modulation on the transmission data. The E / O converters 62 convert the transmission data processed by the DSP 61 from electrical signals to optical signals, and transmit the optical signals to the O / E converters 63 via the optical fiber 60 that transmits the OOK (On-Off-Keying) modulated 1-bit data. The O / E converters 63 convert the optical signals received via the optical fiber 60 into electrical signals. The square wave circuit 64 converts the electrical signals into square waves. The BPF 65 extracts signals of a specific frequency band from the square wave output by the square wave circuit 64. The HPA 66 amplifies the power of the signal that has passed through the BPF 65 and outputs the transmission signal. The antenna 67 then transmits the transmission signal. The square wave circuit 64 may be omitted from the RF wireless transmitter 6, and the BPF 65 and HPA 66 may be provided immediately after the O / E converter 63.

[0006] Normally, RF transmission signals exceeding half the clock frequency for 1-bit conversion cannot be used, but by converting them to square waves, the power level of high-order images is improved, making them usable as RF transmission waves (see non-patent document 1).

[0007] A Manchester-encoded signal is known as a technique for enhancing high-order image signals. Figure 2(a) is a block diagram illustrating an RZ (Return to Zero) signal generation circuit, Figure 2(b) is a block diagram illustrating a Manchester-encoded signal generation circuit, and Figure 2(c) is a timing chart of an NRZ (Non Return to Zero) signal, an RZ signal, and a Manchester-encoded signal.

[0008] In the RZ signal generation circuit shown in Fig. 2(a), an NRZ signal and a CLK signal are input to an AND (logical product) operation circuit, and an RZ signal is output. In the NRZ signal generation circuit shown in Fig. 2(b), an NRZ signal and a CLK signal are input to an XOR (exclusive OR) operation circuit, and a Manchester-encoded signal is output. In this way, a Manchester-encoded signal can be generated by replacing the AND operation circuit of the NRZ signal to RZ signal conversion circuit with an XOR operation circuit.

[0009] In the timing chart shown in FIG. 2(c), the Manchester encoded signal outputs "10" at the timing indicated by reference symbol A1, and outputs "01" at the timing indicated by reference symbol A2.

[0010] Manchester encoding can suppress CLK components, including harmonics, when data does not have a DC component. In addition, the number of pulse edges is doubled compared to RZ, which strengthens higher-order image signals (see Non-Patent Document 1).

[0011] Kenji Suematsu, Mizuki Motoyoshi, and Taku Kameda, "Direct Digital RF Technology," Transactions of the Institute of Electronics, Information and Communications Technology, Vol. J102-C, No. 11, pp. 297-304, November 2019. Junhao Zhang and Noriharu Suematsu, "Image Enhancement Technique Using Manchester Coding and RF Tripler for 1-bit Bandpass Delta Sigma Direct Digital RF Transmitter," IEEE, VOLUME 11, 2023, July 2023.

[0012] Manchester encoding allows the generation of a higher-speed RF signal than a transmitter using 1-bit modulation at the same bit rate. However, for example, in the DSP 61 of the RF wireless transmitter 6 shown in Figure 1, after Manchester encoding, in order to pass the signal through a bandwidth-limited transmission system such as an optical fiber 60, Manchester encoding (see Figure 2(b)) requires the use of a clock frequency that is approximately half that of the normal case (see Figure 2(a)). Note that while 1-bit modulation has the advantage of requiring only half the bit rate (computation speed), there is no significant difference in the upper limit of the transmittable RF frequency.

[0013] For example, an optical fiber transmission system using 10GbE (10Gbps Ethernet) Small Form-factor Pluggable (SFP+) modules guarantees a transmission bandwidth of up to 10Gbps (up to 5GHz). Since there's no need to guarantee transmission above 5GHz, the low-pass characteristics are typically set to 5GHz (even if a bandwidth above 5GHz is achieved, it's meaningless since it's not used for 10GbE data transmission). Incidentally, an optical fiber transmission system using 100GbE QSFP (Quad Small Form-factor Pluggable) 28 modules (25 or 28Gbps with 4 wavelength division multiplexing (WDM)) guarantees a transmission bandwidth of up to 25 or 28Gbps (up to 12.5 or 14GHz).

[0014] In one aspect, the technology described in this specification aims to realize a transmission system that can extract, as an RF transmission signal, an image signal generated in a frequency band exceeding the band limit even through a band-limited transmission system.

[0015] In one aspect, a wireless communication device includes an extraction circuit that transmits a 1-bit modulated transmission data signal through a band-limited transmission system, and then extracts a clock signal from the transmission data signal after transmission, and an arithmetic circuit that performs an exclusive OR operation on the clock signal and the transmission data signal to Manchester encode the transmission data signal.

[0016] As one aspect, it is possible to realize a transmission system that can extract, as an RF transmission signal, an image signal generated in a frequency band exceeding the band limit even if the image signal passes through a band-limited transmission system.

[0017] 1 is a block diagram schematically showing the configuration of a conventional optical fiber transmission direct digital RF radio transmitter; (a) is a block diagram illustrating an RZ signal generation circuit, (b) is a block diagram illustrating a Manchester encoding generation circuit, and (c) is a timing chart of an NRZ signal, an RZ signal, and a Manchester encoded signal; (c) is a graph showing the relationship between normalized frequency and the envelope of power spectral density; (d) is a diagram explaining a 1-bit signal of NRZ code and a 1-bit signal using Manchester code; (e) is a block diagram schematically showing an example of the circuit configuration of a wireless communication device in an embodiment; (f) is a block diagram schematically showing an example of the configuration of a DBF (Digital Beam Forming) transmitter in an embodiment; (f) is a block diagram schematically showing an example of the circuit configuration of a wireless communication device in a first modified example; (f) is a block diagram schematically showing an example of the circuit configuration of a wireless communication device in a second modified example; and (f) is a block diagram schematically showing an example of the circuit configuration of a wireless communication device in a third modified example.

[0018] Hereinafter, embodiments will be described with reference to the drawings. However, the embodiments described below are merely examples, and are not intended to exclude various modifications and applications of techniques not explicitly stated in the embodiments. In other words, the present embodiments can be implemented with various modifications within the scope of the spirit thereof.

[0019] Furthermore, each drawing does not necessarily include only the components shown in the drawing, but may include other components. In the drawings below, parts with the same reference numerals indicate the same or similar parts unless otherwise specified.

[0020] [A] Embodiment FIG. 3 is a graph showing the relationship between normalized frequency and the envelope of the power spectral density.

[0021] 3, the solid curve represents an NRZ signal, the dashed-dotted curve represents an RZ signal attenuated by 50%, and the dashed-two-dot curve represents a Manchester-encoded signal. The bandwidth of the transmission path indicated by symbol B1 is 0 to 0.5 fs (fs: clock frequency).

[0022] In this embodiment, a normal 1-bit modulated transmission data signal (see the signal indicated by the solid arrow in Figure 3) is transmitted through a transmission system with a band limit, and then a clock is extracted from the transmitted data, and the clock and data are XORed to create a Manchester-encoded signal, thereby extracting a high RF transmission signal (the band limit is 1 / 2 at a frequency normalized by the clock frequency in Figure 3).

[0023] FIG. 4 is a diagram for explaining a 1-bit signal using an NRZ code and a 1-bit signal using a Manchester code.

[0024] In the code C1, the DSP 61 that performs 1-bit bandpass delta-sigma modulation outputs an NRZ signal.

[0025] In code C2, a DSP 101 that performs 1-bit bandpass delta-sigma modulation passes an NRZ signal through a band-limited transmission system, and then inputs the NRZ signal and CLK (fs) to an XOR operation circuit 102. The XOR operation circuit 102 then outputs a Manchester-encoded signal (MAN).

[0026] As shown by symbol C3, the NRZ signal is "1" from the rising edge of one clock to the rising edge of the next clock, and thereafter becomes "0." On the other hand, the Manchester encoded signal is "1" while one clock is rising, then becomes "0" and becomes "1" when the rising edge of the next clock has finished.

[0027] Manchester encoding can increase the power level of not only signals around fs but also image signals around 3 fs, making it suitable for direct digital RF transmitters that use high-order images, for example.

[0028] FIG. 5 is a block diagram schematically illustrating an example of the circuit configuration of the wireless communication device 1 according to the embodiment.

[0029] The wireless communication device 1 shown in FIG. 5 may be applied to a terrestrial system or a satellite system. Examples of terrestrial system applications include massive multi-input multi-output (mMIMO) and distributed MIMO. As described below with reference to FIG. 6 , mMIMO allows an indoor unit (IDU) installed inside a building to be connected to an outdoor unit (ODU) installed outdoors with an antenna using lightweight, easy-to-handle optical fiber. mMIMO allows the ODU to be miniaturized. Distributed MIMO allows distributed antennas (DAs) installed in various locations to be connected to a control base station (macro-cell base station (MBS)) using optical fiber, which is more advantageous for long-distance transmission than coaxial cable. Distributed MIMO allows the DA to be miniaturized. In a satellite system, a DSP unit installed inside the satellite body and an antenna module unit installed on the surface of the satellite housing in a position where the Earth can be seen can be connected using lightweight optical fiber.

[0030] The wireless communication device 1 shown in FIG. 5 includes a CDR 10 (Clock Data Recovery), a Manchester encoding circuit 20, a square wave circuit 31, a BPF 32, and a PA 33.

[0031] The CDR 10 is an example of an extraction circuit and includes an injection locking oscillator (ILO) 11 and a delay flip-flop (DFF) 12. The ILO 11 inputs an NRZ signal from the DSP 61 to an optical fiber 100 transmission system, then receives a band-limited 1-bit delta-sigma modulated signal from the optical fiber 100 transmission system, and outputs a clock (CLK) signal. The DFF 12 receives a data signal, which is a band-limited 1-bit delta-sigma modulated signal from the optical fiber 100 transmission system, and the CLK signal from the ILO 11, delays the data signal, and outputs it.

[0032] The Manchester encoding circuit 20 is an example of an arithmetic circuit, and includes an XOR arithmetic circuit 21. The XOR arithmetic circuit 21 performs an exclusive OR operation on the data signal and the clock signal, and inputs the operation result to the rectangular wave circuit 31.

[0033] The squaring circuit 31 converts the input signal into a square wave. The BPF 32 extracts (filters) an RF signal in a predetermined frequency band (for example, a frequency component higher than the frequency of the clock signal) from the signal converted into a square wave. The PA 33 is an example of an amplifier, and amplifies and outputs the RF signal that has passed through the BPF 32. Note that the squaring circuit 31 may be omitted from the wireless communication device 1, and the BPF 32 and PA 33 may be provided immediately after the Manchester encoding circuit 20 (the same applies to FIGS. 7 to 9 described below).

[0034] FIG. 6 is a block diagram schematically illustrating an example of the configuration of the DBF transmitter 4 according to the embodiment.

[0035] The DBF transmitter 4 shown in FIG. 6 includes an IDU 41 and an ODU 42, and the IDU 41 and the ODU 42 are connected via a coaxial power feed cable 100a of, for example, several tens of meters or less.

[0036] The IDU 41 includes a DSP 411 and multiple DACs (Digital / Analog Converters) 412. The DSP 411 receives signals from an aggregation base station (not shown) located, for example, several kilometers away, and performs various processes on the received signals. The DAC 412 converts the digital signals output by the DSP 411 into analog signals and transmits them to the ODU 42 via the coaxial feed cable 100a.

[0037] The ODU 42 includes a plurality of TX modules 421 and a plurality of antennas 422. Each TX module 421 corresponds to the wireless communication device 1 shown in Fig. 5 and transmits an output signal via an antenna 422. The interval between each antenna 422 may be approximately half the wavelength of the transmission signal.

[0038] FIG. 7 is a block diagram schematically illustrating an example of the circuit configuration of a wireless communication device 1a in the first modified example.

[0039] The wireless communication device 1 a shown in FIG. 7 includes a CDR 10 , a Manchester encoding circuit 20 a , two square wave circuits 31 , two BPFs 32 and two PAs 33 .

[0040] The CDR 10 receives a 25 Gbps data signal as input from, for example, a PPG (Pulse Pattern Generator) module or a QSFP module (MDL). The ILO 11 receives an NRZ signal from the DSP 61 into the optical fiber 100 transmission system, then receives a band-limited 1-bit delta-sigma modulated signal from the optical fiber 100 transmission system, and outputs a CLK signal. The DFF 12 receives a two-channel data signal, which is a band-limited 1-bit delta-sigma modulated signal from the optical fiber 100 transmission system, and the CLK signal from the ILO 11, delays the data signal, and outputs it.

[0041] The Manchester encoding circuit 20a includes an S / P (Serial / Parallel) converter 22, a 2-divider 23, and two XOR circuits 21. The S / P converter 22 divides two channels of data signals into one channel of a 12.5 Gbps data signal. The 2-divider 23 distributes the CLK signal from the ILO 11 to the two XOR circuits 21. The two XOR circuits 21 perform exclusive OR operations on the data signal and clock signal, and input the operation results to the corresponding rectangular wave forming circuits 31 for the ANT#1 or ANT#2 systems. Note that the input line from the S / P converter 22 to the XOR circuit 21 at the bottom of the drawing is not connected to the input line from the ILO 11 to the 2-divider 23.

[0042] In each of the ANT#1 system and ANT#2 system, the square wave circuit 31 converts the input signal into a square wave, the BPF 32 extracts (filters) an RF signal of a predetermined frequency band (e.g., a frequency component higher than the frequency of the clock signal) from the signal converted into a square wave, and the PA 33 amplifies the RF signal that has passed through the BPF 32 and outputs it.

[0043] 7, the Manchester encoding circuit 20a includes two XOR operation circuits 21, but this is not limiting. The Manchester encoding circuit 20a may include n (n is an integer equal to or greater than 2) XOR operation circuits 21. In this case, the S / P converter 22 divides the data signal into n parts and inputs them to the XOR operation circuits 21, and an n-divider is provided instead of the 2-divider 23, and the n-divided CLK signal is input to the XOR operation circuits 21. The output from the XOR operation circuit 21 is processed by a set of a rectangular wave circuit 31, a BPF 32, and a PA 33 for each of the ANT#1 to #n systems, and a radio signal (RF) is output.

[0044] FIG. 8 is a block diagram schematically illustrating an example of a circuit configuration of a wireless communication device 1b in the second modified example.

[0045] The wireless communication device 1b shown in FIG. 8 includes a CDR 10a, a Manchester encoding circuit 20b, a square wave circuit 31, a BPF 32, and a PA 33.

[0046] The CDR 10a inputs, for example, a four-wavelength multiplexed (WDM) NRZ signal from the DSP 61 to an optical fiber 100 transmission system, and then accepts the input of the O / E output (for example, ROSA (Receiver Optical Subassembly) output) of the optical fiber 100 transmission system. Note that instead of one WDM optical fiber 100, transmission over four non-WDM optical fibers 100 may be used. However, synchronization must be achieved in the fiber transmitter, and the optical fibers 100 must be of equal length.

[0047] The CDR 10a includes an ILO 11 and four DFFs 12. After inputting an NRZ signal from the DSP 61 to the optical fiber 100 transmission system, the ILO 11 receives a band-limited 1-bit delta-sigma modulated signal from the optical fiber 100 transmission system and outputs a CLK signal. The ILO 11 generates a CLK signal based on one of the four data signals (Data4 in the example shown in FIG. 8 ). The four DFFs 12 receive the corresponding data signals (Data1 to Data4), which are band-limited 1-bit delta-sigma modulated signals from the optical fiber 100 transmission system, and the CLK signal from the ILO 11, delaying and outputting the data signals.

[0048] The Manchester encoding circuit 20b includes four XOR operation circuits 21. Each of the four XOR operation circuits 21 performs an exclusive OR operation on the data signal input from the corresponding DFF 12 and the clock signal input from the ILO 11, and inputs the operation results to the corresponding rectangular wave forming circuits 31 of the ANT#1 to #4 systems.

[0049] In each of the ANT #1 to #4 systems, a square wave circuit 31 converts the input signal into a square wave, a BPF 32 extracts (filters) an RF signal of a predetermined frequency band (for example, a frequency component higher than the frequency of the clock signal) from the signal converted into a square wave, and a PA 33 amplifies the RF signal that has passed through the BPF 32 and outputs it.

[0050] In this way, when a plurality of ANT systems are operated in parallel, the CLK signal can be extracted from one data signal and used in common, thereby achieving synchronization between the antennas.

[0051] 8, the CDR 10a includes four DFFs 12, and the Manchester encoding circuit 20b includes four XOR operation circuits 21, but this is not limiting. The CDR 10a may include m (m is an integer equal to or greater than 2) DFFs 12, and the Manchester encoding circuit 20b may include m XOR operation circuits 21. In this case, outputs from the m XOR operation circuits 21 are processed in sets of rectangular wave circuits 31, BPFs 32, and PAs 33 for each of the ANT#1 to #m systems, and radio signals (RF) are output.

[0052] FIG. 9 is a block diagram schematically illustrating an example of the circuit configuration of a wireless communication device 1c according to the third modified example.

[0053] The wireless communication device 1c shown in FIG. 9 includes a CDR 10a, a Manchester encoding circuit 20a, a square wave circuit 31, a BPF 32, and a PA 33.

[0054] The CDR 10a receives, for example, an input of an O / E output (e.g., a ROSA output) of a four-wavelength multiplexed (WDM) optical fiber 100 transmission system. Note that instead of a single WDM optical fiber 100, transmission over four non-WDM optical fibers 100 may be used. However, synchronization must be achieved in the fiber transmitter, and the optical fibers 100 must be of equal length.

[0055] The CDR 10a includes an ILO 11 and four DFFs 12. After inputting an NRZ signal from the DSP 61 to the optical fiber 100 transmission system, the ILO 11 receives a band-limited 1-bit delta-sigma modulated signal from the optical fiber 100 transmission system and outputs a CLK signal. The ILO 11 generates a CLK signal based on one of four data signals (Data4 in the example shown in FIG. 9 ). The four DFFs 12 receive the corresponding data signals (Data1 to Data4), which are band-limited 1-bit delta-sigma modulated signals from the optical fiber 100 transmission system, and the CLK signal from the ILO 11, delaying and outputting the data signals.

[0056] Each Manchester encoding circuit 20a includes an S / P converter 22, a 2-frequency divider 23, and two XOR operation circuits 21, similar to the wireless communication device 1a shown in Fig. 7. The S / P converter 22 divides two channels of data signals into one channel of a 12.5 Gbps data signal. The 2-frequency divider 23 distributes the CLK signal from the ILO 11 to the two XOR operation circuits 21. The two XOR operation circuits 21 perform exclusive OR operations on the data signal and clock signal, and input the operation results to the corresponding ANT-system rectangular wave forming circuits 31.

[0057] In each of the ANT #1 to #8 systems, a square wave circuit 31 converts the input signal into a square wave, a BPF 32 extracts (filters) an RF signal of a predetermined frequency band (for example, a frequency component higher than the frequency of the clock signal) from the signal converted into a square wave, and a PA 33 amplifies the RF signal that has passed through the BPF 32 and outputs it.

[0058] 9, the CDR 10a includes four DFFs 12, but this is not limiting. The CDR 10a may include m DFFs 12 (m is an integer equal to or greater than 2). In this case, m Manchester encoding circuits 20a, 2m squaring circuits 31, 2m BPFs 32, and 2m PAs 33 are provided. The outputs from the m DFFs 12 are processed in the Manchester encoding circuits 20a, squaring circuits 31, BPFs 32, and PAs 33 of each of the ANT #1 to #2m systems, and radio signals (RF) are output.

[0059] The Manchester encoding circuit 20a may also include n (n is an integer equal to or greater than 2) XOR operation circuits 21. In this case, the S / P converter 22 divides the data signal into n parts and inputs them to each XOR operation circuit 21, and an n-divider is provided instead of the 2-divider 23, and the n-divided CLK signal is input to the XOR operation circuits 21. The output from the XOR operation circuit 21 is processed in a set of a rectangular wave circuit 31, a BPF 32, and a PA 33 for each of the ANT#1 to #m×n systems, and a radio signal (RF) is output.

[0060] According to the above-described embodiment, it is possible to realize a transmission system that can extract, as an RF transmission signal, an image signal generated in a frequency band exceeding the band limit even if the image signal passes through a transmission system with a band limit.

[0061] [B] Others The disclosed technology is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the embodiments. The configurations and processes of the embodiments can be selected or combined as needed.

[0062] In the above-described embodiment, the data signal input to the CDR 10, 10a is transmitted through the optical fiber 100, but this is not limiting. The data signal input to the CDR 10, 10a may be transmitted through various transmission paths with bandwidth limitations, such as a coaxial cable.

[0063] 1, 1a, 1b, 1c: Wireless communication device 100, 60: Optical fiber 100a: Coaxial power supply cable 10, 10a: CDR 11: ILO 12: DFF 20, 20a, 20b: Manchester encoding circuit 21, 102: XOR operation circuit 22: S / P converter 23: 2 frequency divider 31: Square wave circuit 32, 65: BPF 33: PA 4: DBF transmitter 41: IDU 411: DSP 412: DAC 42: ODU 421: TX module 422: Antenna 6: RF wireless transmitter 61, 101: DSP 62: E / O converter 63: O / E converter 64: Square wave circuit 66: HPA 67 : Antenna

Claims

1. A wireless communication device comprising: an extraction circuit that extracts a clock signal from a transmission data signal that has been 1-bit modulated and transmitted through a band-limited transmission system; and an arithmetic circuit that performs an exclusive OR operation on the clock signal and the transmission data signal, thereby Manchester-encoding the transmission data signal.

2. The wireless communication device according to claim 1, wherein the arithmetic circuit divides the clock signal into n (n is an integer of 2 or more) and divides the transmission data signal into n, performs the n parallel exclusive OR operations, and outputs the n Manchester-encoded transmission data signals.

3. The wireless communication device according to claim 1, wherein the extraction circuit extracts the clock signal from one of m transmission data signals (m is an integer of 2 or greater), and the arithmetic circuit performs m parallel exclusive OR operations on the clock signal and the m transmission data signals, and outputs the m Manchester-encoded transmission data signals.

4. The wireless communication device according to claim 1, wherein the extraction circuit extracts the clock signal from one of m (m is an integer of 2 or more) of the transmission data signals, and the arithmetic circuit divides the clock signal into n (n is an integer of 2 or more) and also divides the transmission data signal into n, performs the m x n parallel exclusive OR operation, and outputs the Manchester-encoded m x n transmission data signals.

5. A wireless communication device according to any one of claims 1 to 4, further comprising: a bandpass filter that filters out an RF (Radio Frequency) signal having a frequency component higher than the frequency of the clock signal from the Manchester-encoded signal; and an amplifier that amplifies the RF signal filtered by the bandpass filter.

6. A wireless communication device according to any one of claims 1 to 4, wherein the extraction circuit comprises: an ILO (Injection Locking Oscillator) that extracts the clock signal from the transmission data signal and inputs it to the arithmetic circuit; and a DFF (Delay Flip Flop) that receives the transmission data signal and the clock signal output from the ILO, delays the transmission data signal, and inputs it to the arithmetic circuit.

7. The wireless communication device according to any one of claims 1 to 4, wherein the transmission system is an optical fiber.

8. A wireless communication method using a wireless communication device, wherein the wireless communication device performs the following processes: transmits a 1-bit modulated transmission data signal through a band-limited transmission system, extracts a clock signal from the transmitted transmission data signal, performs an exclusive OR operation on the clock signal and the transmission data signal, and Manchester encodes the transmission data signal.

9. The wireless communication method according to claim 8, wherein the wireless communication device performs the following process: divide the clock signal into n (n is an integer of 2 or more), divide the transmission data signal into n, perform the n parallel exclusive OR operations, and output the n Manchester-encoded transmission data signals.

10. The wireless communication method according to claim 8, wherein the wireless communication device performs the following process: extracting the clock signal from one of m (m is an integer of 2 or more) of the transmission data signals; performing m parallel exclusive OR operations on the clock signal and the m transmission data signals; and outputting the m Manchester-encoded transmission data signals.

11. The wireless communication method according to claim 8, wherein the wireless communication device performs the following processing: extracting the clock signal from one of m (m is an integer of 2 or more) of the transmission data signals; dividing the clock signal into n (n is an integer of 2 or more) and dividing the transmission data signal into n; performing the m×n parallel exclusive OR operation; and outputting the Manchester-encoded m×n transmission data signals.

12. A wireless communication method according to any one of claims 8 to 11, wherein the wireless communication device performs the following processes: filtering an RF (Radio Frequency) signal having a frequency component higher than the frequency of the clock signal from the Manchester-encoded signal; and amplifying the filtered RF signal.

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