Transmitting device, receiving device, communication system, and communication method

Abstract

To provide a transmitting device 1, receiving device, communication system, and communication method capable of simplifying a device configuration necessary to transmit an out-phasing signal.SOLUTION: A transmitting device 1 according to the present disclosure includes: a digital baseband unit DBB that separates a baseband signal into in-phase and quadrature components and outputs them; a quadrature out-phasing signal generator 111 that separates the in-phase component into constant-amplitude signals having first and second phases, and separates the quadrature component into constant-amplitude signals having phases displaced 90 degrees from the first and second phases; a quadrature modulator 112 that quadrature modulates a set of constant-amplitude signals and generates an out-phasing signal; and a time division combining unit 12 that time-division combines a plurality of out-phasing signals and generates a time-division combined signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transmitting device, a receiving device, a communication system, and a communication method. [Background technology]

[0002] Patent documents 1 and 2 disclose an optical wireless transmission system that supplies radio waves at low cost to areas in the access network of a mobile network where radio waves from outdoor base stations have difficulty reaching, such as underground shopping malls and inside buildings. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-304194 [Patent Document 2] Special Publication No. 2008-507164 Summary of the Invention [Problem to be solved by the invention]

[0004] In an optical wireless transmission system in which high-frequency wireless signals generated in the parent device are transmitted directly to the child device via optical fiber, a digital-to-analog converter is not required on the child device side, which is expected to reduce the cost of the child device, increase its efficiency, and make it easier to install.

[0005] On the other hand, in the optical wireless transmission method using outphasing signals, which is a related technology, multiple transmission paths are required to transmit one signal, which requires wavelength multiplexing or the use of multiple optical modules and optical fibers. In either case, this leads to an increase in costs for optical modules and optical fiber wiring. Patent Documents 1 and 2 do not disclose any means capable of solving the above problems.

[0006] The present disclosure has been made to solve such problems, and aims to provide a transmitting device, a receiving device, a communication system, and a communication method that can simplify the device configuration required for transmitting outphasing signals. [Means for solving the problem]

[0007] A transmitting device according to one aspect of the present disclosure includes: a digital baseband unit that separates a baseband signal into an in-phase component and a quadrature component and outputs the separated components; an outphasing signal generator that generates first and second outphasing signals based on the in-phase component and the quadrature component; a time division synthesis unit that synthesizes the first and second outphasing signals in a time division manner to generate a time division synthesis signal; It is a transmitting device.

[0008] A receiving device according to one aspect of the present disclosure includes: a radio signal conversion unit that converts the time division synthesized signal transmitted from the transmitting device into a radio signal; an antenna for radiating the wireless signal, It is a receiving device.

[0009] A communication system according to an embodiment of the present disclosure includes: A communication system including a transmitter and a receiver connected to the transmitter by an optical fiber module, The transmitting device: a digital baseband unit that separates a baseband signal into an in-phase component and a quadrature component and outputs the separated components; an outphasing signal generator that generates first and second outphasing signals based on the in-phase component and the quadrature component; a time division multiplexing unit that time-division multiplexes the first and second outphasing signals; It is a communication system.

[0010] A communication method according to one aspect of the present disclosure includes: generating a plurality of outphasing signals based on the input signal; time-division combining the generated plurality of outphasing signals; The time-division synthesized signal is transmitted from the transmitting side to the receiving side, The signal transmitted from the transmitter is received by the receiver. It is a method of communication. [Effects of the Invention]

[0011] The present disclosure makes it possible to provide a transmitting device, a receiving device, a communication system, and a communication method that can simplify the device configuration required for transmitting an outphasing signal. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a block diagram showing a configuration of a communication system 1001 according to a first embodiment. [Figure 2] 1 is a vector diagram showing the relationship between a desired signal IF(t), a first outphasing signal OP1(t), and a second outphasing signal; [Figure 3] 1 is a graph showing the time waveforms of rectangular outphasing signals S1(t) and S2(t), a composite signal S12(t), and a clock signal CK(t). [Figure 4] FIG. 10 is a block diagram showing a configuration of a communication system 1002 according to another embodiment. [Figure 5] FIG. 10 is a block diagram showing a configuration of a communication system 1003 according to another embodiment. [Figure 6] FIG. 10 is a block diagram showing a configuration of a communication system 1004 according to another embodiment. [Figure 7] FIG. 10 is a block diagram showing the configuration of a communication system 1005 according to another embodiment. [Figure 8] 1 is a block diagram showing a configuration of a transmitting device 1 in a communication system 1005. FIG. [Figure 9] 10 is a block diagram showing a configuration of a receiving device 2 in a communication system 1005. FIG. [Figure 10]10 is a block diagram showing a configuration of a receiving device 2 in a communication system 1005. FIG. [Figure 11] FIG. 10 is a block diagram showing a configuration of a communication system 1006 according to another embodiment. [Figure 12] FIG. 10 is a block diagram showing a configuration of a communication system 1007 according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] (First embodiment) <Communication system configuration> DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A communication system according to a first embodiment of the present disclosure will be described in detail below with reference to the drawings. Fig. 1 is a block diagram showing the configuration of a communication system 1001 according to the first embodiment. The communication system 1001 is made up of a transmitting device 1, a receiving device 2, and an optical fiber module 3 that connects the transmitting device 1 and the receiving device 2. The transmitting device 1 includes a digital baseband unit DBB, an outphasing signal generating unit 11, and a time division combining unit 12.

[0014] The digital baseband unit DBB generates two orthogonal radio signals I and Q. Here, the quadrature radio signals I and Q are modulated signals generated by quadrature modulating a signal desired to be transmitted (hereinafter referred to as a desired signal IF), and are signals with a phase difference of 90 degrees. The signal desired to be transmitted may be called a baseband signal, and the quadrature radio signals I and Q may be called the in-phase and quadrature components of the baseband signal, respectively. In other words, the baseband signal is separated into the in-phase and quadrature components and output.

[0015] The outphasing signal generation unit 11 generates first and second outphasing signals based on the orthogonal radio signals I and Q. The outphasing signal generation unit 11 includes a quadrature outphasing signal generator 111 and first and second quadrature modulators 112a and 112b. Hereinafter, the quadrature modulators 112a and 112b will be simply referred to as quadrature modulator 112 unless there is a particular need to distinguish them.

[0016] The quadrature outphasing signal generator 111 generates a first set of quadrature outphasing signals I1 and Q1 and a second set of quadrature outphasing signals I2 and Q2 from the quadrature radio signals I and Q. where the quadrature outphasing signals I1 and I2 are Q 1 is the quadrature radio signal I and Q is separated into two signals with different phases, and is called an orthogonal outphasing signal. I 2 and Q2 are quadrature radio signals I and This signal is obtained by separating Q into two signals with different phases. Furthermore, the difference in phase between the quadrature outphasing signals I1 and Q1, and the difference in phase between the quadrature outphasing signals I2 and Q2 are both 90 degrees.

[0017] The quadrature modulator 112 converts the input quadrature outphasing signals into a set of quadrature outphasing signals at an intermediate frequency f IF The output signal Sqmod of the quadrature modulator is expressed by the following equation 1. Sqmod = cosω IF t·I in + sinω IF t·Q in ...(Formula 1) where ω IF is the intermediate frequency f IF is the angular frequency obtained by multiplying by 2π, and I in and Q in is a set of quadrature signals input to the quadrature modulator 112.

[0018] The quadrature modulator 112 quadrature-modulates the first pair of quadrature outphasing signals I1 and Q1 based on the above equation 1 to generate an outphasing signal OP1. Furthermore, the quadrature modulator 112 quadrature-modulates the second pair of quadrature outphasing signals I2 and Q2 based on the above equation 1 to generate an outphasing signal OP2.

[0019] As described above, the outphasing signal generation unit 11 of this embodiment separates the orthogonal radio signals I and Q into orthogonal outphasing signals I1, I2, Q1, and Q2, and generates outphasing signals OP1 and OP2 by orthogonally modulating these signals. However, the means by which the outphasing signal generating unit 11 generates the outphasing signals OP1 and OP2 based on the orthogonal radio signals I and Q is not limited to the above method, and for example, the outphasing signals OP1 and OP2 may be generated by an arithmetic circuit that directly generates the signals represented by the mathematical formulas shown on the right-hand sides of Equation 12 and Equation 14 described below.

[0020] The time-division synthesis unit 12 includes first and second rectangular converters 121a and 121b, and a switch circuit 122. Hereinafter, the rectangular converters 121a and 121b will be simply referred to as rectangular converter 121 unless there is a particular need to distinguish them.

[0021] The rectangularizer 121 rectangularizes the input signal by, for example, zero comparison. More specifically, the rectangularizer 121 rectangularizes the outphasing signals OP1 and OP2 by zero comparison, and outputs rectangular outphasing signals S1 and S2.

[0022] The switch circuit 122 combines the two input signals in a time-division manner. More specifically, the switch circuit 122 outputs the rectangular signals S1 and S2 alternately at a predetermined cycle to perform time division synthesis, and generates a synthesis signal S 12 Generate.

[0023] The optical fiber module 3 is composed of an electrical-optical converter E / O that converts an electrical signal into an optical signal, an optical fiber 31, and an optical-electrical converter O / E that converts the optical signal into an electrical signal. The electro-optical converter E / O converts the composite signal S output from the transmitter 1 into 12 is converted into an optical signal and then transmitted to the optical / electrical converter O / E via an optical fiber 31. The optical-to-electrical converter O / E converts the optical signal received from the electrical-to-optical converter E / O into an electrical signal, i.e., a composite signal S 12 and outputs it to the receiving device 2.

[0024] The receiver 2 includes a mixer circuit 21 , a power amplifier AMP, a band-pass filter BPF, and an antenna 22 . The mixer circuit 21 is a mixer that outputs a composite signal S 12 and an LO signal output from a local oscillator (not shown). In other words, the composite signal S output from the optical-electrical converter O / E is 12 More specifically, the mixer circuit 21 converts the frequency of the composite signal S 12 The frequency of the synthesized signal S 12 The mixer circuit 21 converts the frequency of the frequency-converted composite signal S into a frequency that is expressed as the sum or difference of the original frequency of the LO signal and the frequency of the LO signal. 12 is output to the power amplifier AMP.

[0025] The power amplifier AMP amplifies the composite signal S output from the mixer circuit 21. 12 The power amplifier AMP amplifies the amplified composite signal S 12 is output to the band pass filter BPF. The band-pass filter BPF removes frequency components included in a predetermined frequency band and generates a radio signal. For example, the band-pass filter BPF removes the frequency components included in the synthesized signal S 12 The band pass filter BPF removes harmonic components resulting from square wave formation and signal amplification from the wavelength components contained in the signal, and generates a radio signal. The band pass filter BPF outputs the radio signal to the antenna 22. The antenna 22 emits the radio signal output from the band-pass filter BPF into the air as a radio wave.

[0026] With this configuration, the communication system 1001 according to this embodiment can time-division combine multiple outphasing signals and transmit them in a single system. This eliminates the need to connect the transmitter 1 and receiver 2 with multiple optical fiber modules 3, simplifying the device configuration.

[0027] <Communication system operation> Hereinafter, the operation of the communication system according to this embodiment, that is, the communication method according to this embodiment will be described in detail with reference to FIG.

[0028] First, in the transmitting device 1, the digital baseband unit DBB generates orthogonal radio signals I(t) and Q(t). Here, the orthogonal radio signals I(t) and Q(t) are expressed as in the following equations 2 and 3 using an amplitude signal A(t) and a phase signal θ(t). I(t) = A(t) cosθ(t) ...(Formula 2) Q(t) = A(t) sinθ(t) ...(Formula 3)

[0029] However, the amplitude signal A(t) and the phase signal θ(t) in the above equations 2 and 3 are expressed as in the following equations 4 and 5.

[0030]

number

[0031]

number

[0032] Next, in the outphasing signal generating unit 11, the orthogonal outphasing signal generator 111 generates a first set of orthogonal outphasing signals I1(t) and Q1(t) and a second set of orthogonal outphasing signals I2(t) and Q2(t) from the orthogonal radio signals I(t) and Q(t) so as to satisfy the following equations 6 to 9. I1(t) = cos(θ(t) + θ amp (t)) ...(Formula 6) Q1(t) = sin(θ(t) + θ amp (t)) ...(Formula 7) I2(t) = cos(θ(t) - θ amp (t)) ...(Formula 8) Q2(t) = sin(θ(t) - θ amp (t)) ...(Formula 9) However, θ in the above formula amp (t) is a phase signal expressed by the following equation 10. θ amp (t) = arccos(A(t) / 2) ...(Equation 10)

[0033] Next, the first quadrature modulator 112a quadrature modulates the first pair of quadrature outphasing signals I1(t) and Q1(t) and outputs an outphasing signal OP1(t). Furthermore, the second quadrature modulator 112b quadrature-modulates the second pair of quadrature outphasing signals I2(t) and Q2(t) and outputs an outphasing signal OP2(t).

[0034] Here, the outphasing signal OP1(t) output by the first quadrature modulator 112a is expressed as follows in the above-mentioned equation 1: in Substituting the quadrature outphasing signal I1(t) into the quadrature signal Q in The outphasing signal OP1(t) is a signal with a constant amplitude, as shown in the following equation 11. OP1(t) = cosω IF t·I1 + sinω IF t·Q1 ...(Formula 11) Furthermore, when the above formula 11 is transformed, it is expressed as the following formula 12. OP1(t)= cos(ω IF t - θ(t) - θ amp (t)) ...(Equation 12)

[0035] The output signal OP2(t) of the second quadrature modulator 112b is expressed as the quadrature signal I in Substituting the quadrature outphasing signal I2(t) into Q in is obtained by substituting the quadrature outphasing signal Q2(t) into Equation 13 and Equation 14 below, which are signals with constant amplitude. OP2(t) = cosω IF t·I2+ sinω IF t·Q2 ...(Equation 13) OP2(t) = cos(ω IF t - θ(t) + θ amp (t)) ...(Formula 14)

[0036] Considering equations 10, 12, and 14, the sum of the outphasing signals OP1(t) and OP2(t) corresponds to the desired signal IF(t) shown in equation 15 below. IF(t) = A(t) cos(ω IF t - θ(t)) ...(Formula 15) The right side of the above equation is the amplitude signal A(t), the phase signal θ(t), and the carrier frequency is the intermediate frequency f IF This is a general formula for a radio signal, and corresponds to the formula obtained by substituting the orthogonal signals I(t) and Q(t) for the orthogonal signals Iin and Qin, respectively, in the relational formula for the input and output of the quadrature modulator described in formula (1).

[0037] The relationships in the above equations can also be explained using a vector diagram as shown in Figure 2. That is, the desired signal IF(t) can be represented as a vector with magnitude A(t) and phase θ(t), and the outphasing signal OP1(t) has phase θ(t)-θ amp (t), and the outphasing signal OP2(t) can be expressed as a unit vector with phase θ(t)+θ amp (t) can be expressed as a unit vector.

[0038] Next, the first and second rectangularizers 121a and 121b respectively acquire the outphasing signals OP1(t) and OP2(t) and output rectangular outphasing signals S1(t) and S2(t). More specifically, the rectangularizer 121 outputs a signal with an amplitude value of 1 when the amplitude values ​​of the outphasing signals OP1(t) and OP2(t) are greater than zero, and outputs a signal with an amplitude value of −1 when the amplitude values ​​are less than zero, thereby outputting the rectangular outphasing signals S1(t) and S2(t). In other words, the rectangularized signals S1(t) and S2(t) are digital signals with amplitude values ​​of 1 or −1. When the amplitude values ​​of the outphasing signals OP1(t) and OP2(t) are zero, they are made to correspond to either a signal with an amplitude value of 1 or a signal with an amplitude value of −1, but it does not matter which one they are made to correspond to.

[0039] Here, rectangular outphasing signals S1(t) and S2(t), which are output signals from the first and second rectangularizers 121a and 121b, are expressed by the following equations 16 and 17. S1(t) = OP1(t) + Rec(OP1(t)) ...(Equation 16) S2(t) = OP2(t) + Rec(OP2(t)) ...(Formula 17) The function Rec(t) is a signal distortion component generated by the rectangularization process, and corresponds to the difference between the output signal and the input signal of the rectangularization device.

[0040] Here, the sum S of the rectangular outphasing signals S1(t) and S2(t) is DES(t) is expressed by the following equation 18. S DES (t) = S1(t) + S2(t) = OP1(t) + OP2(t) + Rec(OP1(t)) + Rec(OP2(t)) ...(Formula 18)

[0041] Considering that the sum of the outphasing signals OP1(t) and OP2(t) is equal to the desired signal IF(t), the above equation 18 can be transformed into the following equation 19. According to equation 19, S DES (t) includes the desired signal IF(t) as a component. S DES (t) = IF(t) + Rec(OP1(t)) + Rec(OP2(t)) ...(Formula 19)

[0042] Next, the switch circuit 122 time-division combines the rectangular outphasing signals S1(t) and S2(t) to generate a combined signal S 12 Specifically, the input signals S1(t) and S2(t) are switched and output in accordance with the H / L level of a clock signal CK output from a clock signal oscillator (not shown).

[0043] FIG. 3 shows the rectangular outphasing signals S1(t) and S2(t), the composite signal S 12 10 is a graph showing the time waveforms of the clock signal CK(t) and the clock signal CK(t). 3, when the amplitude value of the clock signal is 1, the switch circuit 122 outputs the rectangular outphasing signal S1(t), and when the amplitude value of the clock signal is -1, the switch circuit 122 outputs the waveform of the rectangular outphasing signal S2(t). By alternately outputting the rectangular outphasing signals S1(t) and S2(t) at a predetermined cycle in this way, the composite signal S 12 Generate (t).

[0044] The composite signal S obtained from the switch circuit 122 12 (t) is expressed as the following equation 20. S 12(t) = S1(t) {CK(t)+1} / 2 + S2(t) {-CK(t)+1} / 2 ...(Formula 20) Furthermore, by modifying the above equation 20, the output signal S 12 (t) is expressed as the following equation 21. S 12 (t) = [S1(t) + S2(t) + {S1(t) - S2(t)}·CK(t)] / 2 ...(Formula 21) Also, considering Equation 18, the output signal S 12 (t) is expressed as the following equation 22. S 12 (t) = [S DES (t) + {S1(t) - S2(t)}·CK(t)] / 2 ...(Formula 22)

[0045] From the above equation 22, the composite signal S 12 (t) is the S shown in Equation 18 and Equation 19. DES (t) is included in the composite signal S 12 Among the signal components contained in (t), S DES Signal components other than (t) are unwanted signal components. Here, if the frequency of the clock signal CK(t) is sufficiently high, the frequency band occupied by the unwanted signal components is S DES (t) frequency band is significantly higher.

[0046] Next, the optical fiber module 3 receives the composite signal S output from the switch circuit 122. 12 (t) is transmitted to the receiving device 2. More specifically, the composite signal S output by the switch circuit 122 12 The electrical-to-optical converter E / O converts the received optical signal into an optical signal, which is then transmitted to the optical-to-electrical converter O / E via the optical fiber 31. The optical-to-electrical converter O / E then converts the received optical signal into an electrical signal, i.e., the composite signal S 12 (t) and output to the receiving device 2.

[0047] Next, the mixer circuit 21 receives the composite signal S from the optical-to-electrical converter O / E. 12(t) is obtained and frequency-converted by the mixer circuit 21. 12 (t) represents the frequency of the desired signal IF(t) as f IF , the frequency of the external LO signal is f LO Then, f IF +f LO and f IF -f LO The frequency components are included. The final frequency of the radio signal emitted is f DES Then, the frequency of the external LO signal, f LO is f DES -f IF , or f DES +f IF It is recommended to set it to .

[0048] Next, the power amplifier AMP outputs the frequency-converted composite signal S 12 (t) is amplified. Then, the bandpass filter BPF amplifies the amplified composite signal S 12 Remove unnecessary frequency components from (t). The band-pass filter BPF is a filter that filters the above-mentioned frequency component f IF +f LO and f IF -f LO Either one of the above is selected, and frequency components other than the selected frequency component are removed as unnecessary frequency components.

[0049] Furthermore, as mentioned above, when the frequency of the clock signal CK(t) is sufficiently high, the frequency band occupied by the unnecessary signal components is S DES Therefore, when the frequency of the clock signal CK(t) is sufficiently high, the bandpass filter BPF can sufficiently remove unwanted signal components.

[0050] Finally, the radio signal output from the band-pass filter BPF is radiated by the antenna 22, completing the series of operations.

[0051] As described above, the communication system 1001 according to this embodiment transmits an outphasing signal by time division synthesis, and therefore can transmit the outphasing signal in a single system. Therefore, the communication system 1001 according to this embodiment can simplify the device configuration required for transmitting the outphasing signal.

[0052] (Other embodiments) 4 is a block diagram showing the configuration of a communication system 1002 according to another embodiment. The communication system 1002 differs from the communication system 1001 according to the first embodiment in that the receiving device 2 does not include the mixer circuit 21. In the communication system 1002, the composite signal S 12 is radiated from the antenna via the power amplifier AMP and the bandpass filter BPF. That is, the frequency of the radio signal radiated from the antenna 22 corresponds to the intermediate frequency set when the rectangular outphasing signals S1 and S2 were generated. With this configuration, the communication system 1002 can simplify the configuration of the receiving device 2.

[0053] 5 is a block diagram showing the configuration of a communication system 1003 according to another embodiment. The communication system 1003 differs from the communication system 1001 according to the first embodiment in that the receiving device 2 is equipped with a signal regeneration unit 23. The signal reproducing unit 23 includes a switch circuit 231 and an adder 232. The switch circuit 231 outputs the composite signal S 12 into rectangular outphasing signals S1 and S2. The adder 232 combines the separated rectangular outphasing signals S1 and S2 to produce a signal S DES is output to the mixer circuit 21. With this configuration, it is possible to suppress the generation of unnecessary signal components due to time-division synthesis.

[0054] 6 is a block diagram showing the configuration of a communication system 1004 according to another embodiment. The communication system 1004 differs from the communication system 1001 according to the first embodiment in that the receiving device 2 does not include the mixer circuit 21 and includes a signal regeneration unit 23. In the communication system 1004, the output signal of the signal regeneration unit 23 is radiated from the antenna 22 via a power amplifier AMP and a bandpass filter BPF. That is, the frequency of the radio signal radiated from the antenna corresponds to the intermediate frequency of the rectangular outphasing signals S1 and S2, as in the case of the communication system 1002. With this configuration, the communication system 1004 can simplify the configuration of the receiving device 2 compared to the communication system 1003.

[0055] 7 is a block diagram showing the configuration of a communication system 1005 according to another embodiment. The communication system 1005 is an application example of the communication system 1001 or 1002. The communication system 1005 is an example in which massive MIMO (Multiple Input and Multiple Output) transmission is applied to the communication system 1001 or 1002. In other words, the communication system 1005 is an example in which multiple time-division synthesized signals are wavelength-multiplexed and transmitted.

[0056] FIG. 8 is a block diagram showing the configuration of the transmitting device 1 in the communication system 1005. As shown in FIG. Unlike the communication systems 1001 and 1002, the transmitting device 1 in the communication system 1005 includes n outphasing signal generating units 11 and n time division synthesizing units 12 in a single device, where n is an integer greater than 2. Moreover, unlike the case of the communication system 1002, the transmitting device 1 is connected to a converter WDM-E / O that can wavelength division multiplex and transmit a plurality of signals. In the transmitting device 1 of the communication system 1005, first, the digital baseband unit DBB outputs n pairs of orthogonal radio signals I and Q. Next, the n outphasing signal generators 11 and the time division combiner 12 generate n systems of combined signals S12 , i.e., the composite signal S 12 -1~S 12 The transmitting device 1 in the communication system 1005 generates these n-channel composite signals S 12 -1~S 12 The WDM-E / O converter outputs n-channel composite signals S 12 -1~S 12 -n is converted into an optical signal, wavelength division multiplexed, and transmitted to the receiving device 2 via an optical fiber.

[0057] 9 and 10 are block diagrams showing the configuration of the receiving device 2 in the communication system 1005. FIG. FIG. 9 shows a configuration of a receiving device 2 that includes a mixer circuit 21, and FIG. 10 shows a configuration of a receiving device 2 that does not include a mixer circuit 21, but either configuration will do. 9, the receiving device 2 of the communication system 1005 includes n mixer circuits 21, power amplifiers AMP, band-pass filters BPF, and an antenna 22. Also, in the case of FIG. 10, the receiving device 2 includes n power amplifiers AMP, band-pass filters BPF, and an antenna 22. Furthermore, the receiving device 2 in the communication system 1005 is connected to a converter WDM-O / E that can demultiplex a wavelength-multiplexed optical signal and convert it into an electrical signal.

[0058] The WDM-O / E converter separates the wavelength-multiplexed optical signals received from the WDM-E / O converter, and converts the separated optical signals into electrical signals, i.e., n-system combined signals S 12 -1~S 12 Then, the receiving device 2 converts the composite signal S 12 -1~S 12 The signals 22-1 to 22-n are converted into radio signals and radiated from a plurality of antennas 22-1 to 22-n.

[0059] Such a configuration makes it possible to perform beamforming for any number of users. Furthermore, by wavelength-multiplexing and transmitting n-system signals, the number of optical fibers can be reduced, thereby reducing costs.

[0060] 11 is a block diagram showing the configuration of a communication system 1006 according to another embodiment. The communication system 1006 is an application example of the communication system 1001 or 1002. The communication system 1006 is an example in which distributed MIMO transmission is applied to the communication system 1001 or 1002.

[0061] In the transmitting device 1 of the communication system 1006, first, n digital baseband units DBB-1 to DBB-n output n pairs of orthogonal radio signals I and Q. Next, each of the n pairs of orthogonal radio signals I and Q is converted into a combined signal S via an outphasing signal generating unit and a time division combining unit. 12 -1~S 12 These signals are converted into multiple composite signals S 12 -1~S 12 -n are each sent to a different receiving device 2. Although the receiving device 2 shown in FIG. 11 does not include the mixer circuit 21, it may include the mixer circuit 21.

[0062] 12 is a block diagram showing the configuration of a communication system 1007 according to another embodiment. The communication system 1007 is an application example of the communication system 1001 or 1002. The communication system 1007 is an example in which an analog beamforming function is added to the receiving device 2 according to the communication system 1001 or 1002. The receiving device 2 in the communication system 1007 includes n phase shifters 24-1 to 24-n and antennas 22-1 to 22-n. The phase shifters 24-1 to 24-n adjust the phase of the radio signal output from the band pass filter BPF and output the signal to the antennas 22-1 to 22-n corresponding to the phase shifters 24-1 to 24-n, respectively. The antennas 22-1 to 22-n emit the phase-adjusted radio signal, thereby transmitting the radio signal in any direction. Instead of the phase shifter, an analog beamforming feeding circuit may be used. Furthermore, although the receiving device 2 shown in FIG. 12 does not include the mixer circuit 21, it may include the mixer circuit 21. [Explanation of symbols]

[0063] 1. Transmitting device 2. Receiving device 3. Optical fiber module 11 Outphasing signal generator 12 Time division synthesis section 21 Mixer circuit 22 Antenna 23 Signal regeneration section 24 Phaser 232 Adder 31 Optical Fiber 111 Quadrature Outphasing Signal Generator 112, 112a, 112b Quadrature modulator 121, 121a, 121b rectangle 122, 231 Switch circuits 1001, 1002, 1003, 1004, 1005, 1006, 1007 Communication Systems DBB Digital Baseband Section AMP Amplifier BPF Bandpass Filter E / O Electrical / Optical Converter O / E Optical / Electrical Converter

Claims

1. A digital baseband section that separates the baseband signal into an in-phase component and a quadrature component and outputs them. 、 generating first and second outphasing signals based on the in-phase and quadrature components; an outphasing signal generator for generating an outphasing signal; time-division combining the first and second outphasing signals to generate a time-division combined signal; a time division synthesis unit for synthesizing the received signal; transmitting the time-division synthesized signal generated by the time-division synthesis unit; Transmitting device.

2. The first and second outphasing signals generated by the outphasing signal generator a squarer for square-forming the signal; The time division synthesis unit time-divides the rectangularized first and second outphasing signals. Composite, The transmitting device according to claim 1 .

3. The time division synthesis unit alternately synthesizes the first and second outphasing signals at a predetermined period. and outputting the first and second outphasing signals to the time-division combining unit.

3. The transmitting device according to claim 1 or 2.

4. A plurality of the time-division composite signals are wavelength-division multiplexed and transmitted.

4. The transmitting device according to claim 1.

5. The time-division synthesized signal transmitted from the transmitting device according to any one of claims 1 to 4 is an amplifier for amplifying the signal; A frequency component included in a predetermined frequency band is removed from the signal obtained by amplifying the time-division synthesized signal. and a bandpass filter for generating a radio signal. an antenna for radiating the wireless signal, Separating the time division composite signal; The radio signal is then transmitted based on the signal obtained by adding the separated signals. Generate, Receiving device.

6. A transmitter and a receiver connected to the transmitter by an optical fiber module. A communication system comprising: The transmitting device: A digital baseband section that separates the baseband signal into an in-phase component and a quadrature component and outputs them. 、 generating first and second outphasing signals based on the in-phase and quadrature components; an outphasing signal generator for generating an outphasing signal; time-division combining the first and second outphasing signals to generate a time-division combined signal; a time division synthesis unit; transmitting the time-division synthesized signal generated by the time-division synthesis unit; Communication system.

7. The receiving device: an amplifier for amplifying the time-division composite signal transmitted from the transmitting device; A frequency component included in a predetermined frequency band is removed from the signal obtained by amplifying the time-division synthesized signal. and a bandpass filter for generating a radio signal. an antenna for radiating the wireless signal; 7. The communication system according to claim 6.

8. generating a plurality of outphasing signals based on the input signal; time-division combining the generated plurality of outphasing signals; The time-division synthesized signal is transmitted from the transmitting side to the receiving side, The signal transmitted from the transmitter is received by the receiver. Communication method.

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