WO2017079871A1 - 一种调制器、调制系统以及实现高阶调制的方法 - Google Patents

一种调制器、调制系统以及实现高阶调制的方法 Download PDF

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Publication number
WO2017079871A1
WO2017079871A1 PCT/CN2015/094119 CN2015094119W WO2017079871A1 WO 2017079871 A1 WO2017079871 A1 WO 2017079871A1 CN 2015094119 W CN2015094119 W CN 2015094119W WO 2017079871 A1 WO2017079871 A1 WO 2017079871A1
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Prior art keywords
transmission curve
curve
adjusted
transmission
phase
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PCT/CN2015/094119
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English (en)
French (fr)
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刘磊
方圆圆
邓舒鹏
王志仁
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华为技术有限公司
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Priority to PCT/CN2015/094119 priority Critical patent/WO2017079871A1/zh
Priority to EP15908001.9A priority patent/EP3364622B1/en
Priority to CN201580081858.8A priority patent/CN107852390B/zh
Publication of WO2017079871A1 publication Critical patent/WO2017079871A1/zh
Priority to US15/974,489 priority patent/US10270632B2/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/20—Modulator circuits; Transmitter circuits
    • H04L27/2096—Arrangements for directly or externally modulating an optical carrier
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/25—Arrangements specific to fibre transmission
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/501—Structural aspects
    • H04B10/503—Laser transmitters
    • H04B10/505—Laser transmitters using external modulation
    • H04B10/5053—Laser transmitters using external modulation using a parallel, i.e. shunt, combination of modulators
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/58—Compensation for non-linear transmitter output
    • H04B10/588—Compensation for non-linear transmitter output in external modulation systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0008—Modulated-carrier systems arrangements for allowing a transmitter or receiver to use more than one type of modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/20—Modulator circuits; Transmitter circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/21—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  by interference
    • G02F1/225—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  by interference in an optical waveguide structure

Definitions

  • the present invention relates to signal modulation in the field of communications, and more particularly to a modulator, a modulation system, and a method of implementing higher order modulation.
  • the 100G system uses quadrature phase shift keying (English full name: quadrature phase shift keying, English abbreviation: QPSK) modulation technology, coherent detection technology and digital signal processing (English full name: digital signal processing, English abbreviation: DSP) technology to the system
  • QPSK quadrature phase shift keying
  • DSP digital signal processing
  • the optical signal-to-noise ratio (English full name: Optical Signal Noise Ratio, English abbreviation: OSNR) reduces the tolerance to the same magnitude of 10G, which reduces the system requirements for fiber.
  • the OSNR limitation and noise and nonlinearity caused by the 400G system will limit the transmission distance.
  • dual-carrier and quadrature amplitude modulation English name: quadrature amplitude modulation, English abbreviation: 16QAM
  • the transmission distance of the 400G system is only about 1/3 of that of the 100G system, so the construction of the high-rate system needs to comprehensively consider the system capacity and transmission distance requirements.
  • FIG. 1 is a schematic structural diagram of implementing QPSK and PDM-QPSK in the prior art. A sinusoidal modulation curve can be obtained using this modulation architecture.
  • the modulation curve is a sinusoidal curve
  • a digital-to-analog converter (English full name: digital to analog converter, DAC) is required for nonlinear compensation, which will increase the number.
  • Signal processor English full name: digital signal Processor, English abbreviation: DSP
  • DSP digital signal Processor
  • Embodiments of the present invention provide a modulator, a modulation system, and a method for implementing high-order modulation, which can obtain a modulatable linear result by controlling a superposition ratio between transmission curves, thereby realizing transmission of a linear curve, and is suitable for various modulations. Scenarios enhance the flexibility of the solution.
  • a first aspect of the embodiments of the present invention provides a modulator, including:
  • a first modulation module configured to receive first to-be modulated data, and output a first transmission curve according to the first to-be-modulated data
  • a second modulation module configured to receive second data to be modulated, and output a second transmission curve according to the second data to be modulated, wherein a period of the second transmission curve is two of a period of the first transmission curve One of the points;
  • a synthesizing module configured to superimpose the first transmission curve and the second transmission curve on a phase to obtain a synthesized linear result.
  • the modulator further includes an asymmetric coupling module
  • the asymmetric coupling module is configured to add a preset phase shift value to the first transmission curve to obtain an offset first transmission curve
  • the synthesizing module is further configured to perform phase superposition on the offset first transmission curve and the second transmission curve to obtain a synthesized linear result.
  • the modulator further includes a first phase shifting module and a first attenuation module;
  • the first phase shifting module is configured to perform phase adjustment on the first transmission curve and the second transmission curve, and obtain an adjusted first transmission curve and an adjusted second transmission curve, so as to
  • the synthesis module performs phase superposition on the adjusted first transmission curve and the adjusted second transmission curve to obtain a synthesized linear result
  • the first attenuation module is configured to control a scale ratio of the adjusted first transmission curve and the adjusted second transmission curve to pre-compensate the linear result according to the curve proportional size. And output the linear result after pre-compensation.
  • the modulator further includes a third modulation module, a second phase shift module, and a second attenuation module;
  • the third modulation module is configured to receive third to-be modulated data, and output a third transmission curve according to the third to-be-modulated data, where a period of the third transmission curve is a period of the second transmission curve One-half;
  • the second phase shifting module is configured to perform phase adjustment on the first transmission curve, the second transmission curve, and the third transmission curve, and obtain the adjusted first transmission curve, the Adjusting the second transmission curve and the adjusted third transmission curve, so that the synthesizing module sets the adjusted first transmission curve, the adjusted second transmission curve, and the adjusted third transmission curve Perform superposition on the phase to obtain a linear result after synthesis;
  • the second attenuation module is configured to control a scale ratio of the adjusted first transmission curve, the adjusted second transmission curve, and the adjusted third transmission curve to be proportional to the scale of the curve
  • the linear result is pre-compensated and the pre-compensated linear result is output.
  • the first modulation module is connected to the first phase shifting module, and the first phase shifting module is The second modulation module is connected to the first attenuation module.
  • a second aspect of the embodiments of the present invention provides a system for implementing high-order modulation, including: the system includes at least one modulator;
  • the modulator is as in the first aspect of the invention, and the modulator of any one of the first to fourth possible implementations of the first aspect.
  • a third aspect of the embodiments of the present invention provides a method for implementing high-order modulation, which includes:
  • the first transmission curve and the second transmission curve are superimposed in phase to obtain a synthesized linear result.
  • the method before the superimposing the first transmission curve and the second transmission curve in a phase, the method further includes:
  • the method before the superimposing the first transmission curve and the second transmission curve in a phase, the method further includes:
  • the method further includes :
  • the receiving the first to-be-modulated data, and outputting the first transmission curve according to the first to-be-modulated data further includes:
  • the method further includes:
  • a modulator for implementing high-order modulation is provided, and the modulator can modulate the received first to-be-modulated data and the second to-be-modulated data, and output a corresponding first transmission curve and a first The second transmission curve, wherein the second transmission curve is in a multiple relationship with the period of the first transmission curve, and the two transmission curves are superimposed on the phase to obtain a desired linear result.
  • the modulator realizes the transmission of the linear curve by superimposing the phase on the first transmission curve and the second transmission curve, and is suitable for various modulation scenarios, thereby enhancing the flexibility of the scheme.
  • the above process can eliminate the need for high-order modulation, and additionally use a digital-to-analog converter to perform nonlinear compensation, which can reduce the compensation power consumption and chip scale of the digital signal processor.
  • 1 is a schematic structural diagram of implementing QPSK and PDM-QPSK in the prior art
  • FIG. 2 is a schematic diagram of a transmission curve in an embodiment of the present invention.
  • FIG. 3 is a schematic structural diagram of a modulator in a theoretical simulation according to an embodiment of the present invention.
  • FIG. 4 is a schematic diagram showing a comparison of a modulation curve outputted by a modulator and a modulation curve output by a conventional modulator according to an embodiment of the present invention
  • FIG. 5 is a schematic diagram of an embodiment of a modulator for implementing high-order modulation in an embodiment of the present invention
  • FIG. 6 is a schematic diagram of another embodiment of a modulator for implementing high-order modulation in an embodiment of the present invention.
  • FIG. 7 is a schematic structural diagram of a modulator in an embodiment of the present invention.
  • FIG. 8 is a schematic diagram of a comparison of light field transmission curves in an embodiment of the present invention.
  • FIG. 9 is a schematic diagram of another embodiment of a modulator for implementing high-order modulation in an embodiment of the present invention.
  • FIG. 10 is another schematic structural diagram of a modulator in an embodiment of the present invention.
  • FIG. 11 is another comparative schematic diagram of a light field transmission curve in an embodiment of the present invention.
  • FIG. 12 is another schematic structural diagram of a modulator in an embodiment of the present invention.
  • FIG. 13 is another schematic structural diagram of a modulator in an embodiment of the present invention.
  • FIG. 15 is a schematic diagram of an embodiment of a method for implementing high-order modulation according to an embodiment of the present invention.
  • Embodiments of the present invention provide a modulator, a modulation system, and a method for implementing high-order modulation, which can obtain an adjustable linear result by controlling a superposition ratio between transmission curves, thereby realizing transmission of a linear curve, and is suitable for various modulations.
  • a modulator for implementing high-order modulation, which can obtain an adjustable linear result by controlling a superposition ratio between transmission curves, thereby realizing transmission of a linear curve, and is suitable for various modulations.
  • Figure 1 through Figure 15 The detailed description will be respectively made below through specific embodiments.
  • the modulator provided by the embodiment of the present invention can be applied to high-speed optical transmission technologies such as mobile internet, cloud computing, and the Internet.
  • high-speed optical transmission system can also be other systems such as a 400Gb/s high-speed optical transmission system.
  • the core network router interconnection has become a key driver of 40Gb/s, which has promoted the development of 40Gb/s modulation pattern technology for the backbone network dense optical wave multiplexing (English full name: Dense Wavelength Division Multiplexing, English abbreviation: DWDM) transmission system.
  • 40Gb/s can better meet the demand for broadband service traffic growth of the Internet Protocol (English name: Internet Protocol, English abbreviation: IP), with higher integration, saving space, power and operating and maintenance costs.
  • IP Internet Protocol
  • the 40-bit/s DWDM transmission system has a 4x degradation in optical signal-to-noise ratio (Optical Signal Noise Ratio, OSNR) and a 16-fold reduction in chromatic dispersion capacity.
  • Polarization Mode Dispersion (English name: Polarization Mode Dispersion, English abbreviation: PMD) is degraded by 4 times, and the nonlinear effect is more obvious. Therefore, in order to improve transmission performance and reduce the limitations of OSNR, PMD, nonlinearity and dispersion, the application of advanced modulation patterns has become one of the key technologies for transmission. The three mainstream modulation patterns will be described below.
  • differential phase shift keying (English full name: Differential Phase Shift Keying, English abbreviation: DPSK);
  • the widely used modulation format in optical fiber transmission systems is amplitude-based on-off keying modulation (English full name: On-Off Keying, English abbreviation: OOK), which is directly detected.
  • Phase-based DPSK modulation and QPSK are introduced to improve the nonlinear tolerance based on the pre-turn technique.
  • the pre-twist is used to counteract the ripple generated by the pulse itself due to the process of emission and propagation, to achieve the effect of the compression pulse, to extend the transmission distance, and to improve the transmission performance.
  • the DQPSK modulation pattern has delayed differential reception and coherent reception, and the differential reception performance is inferior to coherent reception.
  • Coherent reception uses a QPSK modulation pattern that utilizes four different phases of the carrier to characterize the digital information. Since each carrier phase represents two bits of information, each quaternary symbol is also referred to as a two-bit symbol. The previous information bits constituting the two-bit symbol are represented by a, and the latter information bits are represented by b. The two information bits ab in a two-bit symbol are usually arranged by Gray code, that is, the reflection code.
  • Gray code that is, the reflection code.
  • DP-QPSK transmits two different signals through polarization-multiplexed DQPSK modulation pattern, or dual-polarization QPSK, which uses two orthogonal polarization states. Although the frequencies are the same, they are 90° different in polarity. It does not affect each other, the spectral efficiency is doubled compared to DQPSK, and it becomes 4 bits per symbol, so it can be obtained with the traditional 10Gb/s non-return-to-zero key system (English name: Non-Return to Zero On -Off Keying, English abbreviation: NRZ-OOK) Similar noise characteristics of the transmission system.
  • 10Gb/s non-return-to-zero key system English name: Non-Return to Zero On -Off Keying, English abbreviation: NRZ-OOK
  • the DP-QPSK modulation pattern signal adopts polarization diversity and digital coherent reception technology, and the signal light is decomposed into two orthogonal polarization signals by a polarization beam splitter (English name: Polarizing beam splitter, English abbreviation: PBS).
  • the cross-polarized signals are mixed with a local light source with a carrier frequency control accuracy of several hundred kilohertz (English name: kilohertz, English abbreviation: kHz).
  • a modulator is designed mainly for the compensation of the nonlinear effect, and the linear result of the modulation can be obtained by controlling the superposition ratio between the transmission curves, thereby realizing the transmission of the linear curve.
  • MZM Mach-Zehnder modulator
  • the half-wave voltage V pi of the MZM device is a multiple relationship, and the cascade connection manner may be a parallel connection or a serial connection.
  • the signals are synthesized with different light field intensity ratios, and the shape of the curve synthesis is controlled by controlling the split ratio between MZMs, so that the transmission curve can be adjusted.
  • FIG. 2 is a schematic diagram of a transmission curve according to an embodiment of the present invention.
  • the transmission curve is sinusoidal and the light field decreases as the splitting ratio decreases.
  • Curve No. 2 is the transmission curve obtained after the modulation of the embodiment of the present invention. Compared with the curve No. 1, it tends to be more linear, and the light field still decreases as the splitting ratio decreases.
  • FIG. 3 is a schematic structural diagram of a modulator in a theoretical simulation according to an embodiment of the present invention.
  • P is the forward voltage
  • N is the negative voltage
  • the positive voltage is equal to twice the negative voltage
  • V pi_upper 2V pi_lower
  • V pi is the half-wave voltage.
  • the half-wave voltage refers to the voltage to be applied when the optical wave propagates in the optical crystal when the optical path difference between the two vertical components Ex' and Ey' of the optical wave is half wavelength (that is, the corresponding phase difference is 180 degrees).
  • Figure 3 introduces the method of introducing a phase shift by a directional coupler instead of a mode-locked laser (English name: MLL).
  • a phase shift unit can also be introduced at the positive voltage output to output modulation. curve.
  • FIG. 3 only the curves outputted by cascading two MZM devices are synthesized.
  • the embodiment of the present invention is not limited to the cascade of two MZM devices, and therefore, the modulation curve of the output may be superimposed by a plurality of curves. Into. The following describes how to output the synthesized modulation curve:
  • ⁇ (t) represents a function of the curve and time
  • ⁇ 0 is the initial value of the light field when the voltage is
  • j is the imaginary unit
  • ⁇ 0 t is the initial value of the angle when the voltage is
  • ⁇ a is at V pi_upper
  • ⁇ b is the offset angle at V pi_lower voltage
  • V pi_upper 2V pi_lower .
  • FIG. 4 is a schematic diagram showing a comparison of a modulation curve outputted by a modulator and a modulation curve output by a conventional modulator according to an embodiment of the present invention.
  • FIG. 5 is a schematic diagram of an embodiment of a modulator for implementing high-order modulation according to an embodiment of the present invention, to implement high-order modulation.
  • Modulator 100 comprising:
  • the first modulation module 101 is configured to receive first data to be modulated, and output a first transmission curve according to the first data to be modulated;
  • a second modulation module 102 configured to receive second to-be modulated data, and output a second transmission curve according to the second to-be-modulated data, wherein a period of the second transmission curve is a period of the first transmission curve Half;
  • a synthesizing module 103 configured to superimpose the first transmission curve received by the first modulation module 101 and the second transmission curve received by the second modulation module 102 to obtain a synthesized linearity result.
  • the modulator for implementing high-order modulation has three modules, which are a first modulation module, a second modulation module, and a synthesis module, respectively.
  • the first modulation module receives the first data to be modulated and outputs the first data to be modulated to obtain a corresponding first transmission curve, and the first transmission curve is sinusoidal.
  • the second modulation module receives the second data to be modulated, and outputs the second data to be modulated to obtain a corresponding second transmission curve.
  • the second transmission curve is also sinusoidal, however, due to the positive voltage There is a voltage difference between the voltage and the negative voltage, the negative electrode The voltage is half of the positive voltage, so the period of the resulting second transmission curve is one-half of the period of the first transmission curve.
  • the synthesizing module synthesizes the first transmission curve and the second transmission curve, and the specific method of synthesizing is similar to the scheme introduced in the embodiment corresponding to the above 3, that is, superposition of functions.
  • a modulator for implementing high-order modulation is provided, and the modulator can modulate the received first to-be-modulated data and the second to-be-modulated data, and output a corresponding first transmission curve and a first The second transmission curve, wherein the second transmission curve is in a multiple relationship with the first transmission curve, and the two transmission curves are superimposed on the phase to obtain a desired linear result.
  • the modulator can obtain a modulatable linear result by controlling the superposition ratio between the transmission curves, thereby realizing the transmission of the linear curve, which is suitable for various modulation scenarios and enhances the flexibility of the scheme.
  • FIG. 6 is a high-order implementation in the embodiment of the present invention.
  • FIG. 6 is a high-order implementation in the embodiment of the present invention.
  • the asymmetric coupling module 104 is configured to add a preset phase shift value to the first transmission curve to obtain an offset first transmission curve;
  • the synthesizing module 103 is further configured to perform phase superposition on the offset first transmission curve and the second transmission curve to obtain a synthesized linear result.
  • the first transmission curve needs to be phase-shifted, and the offset may be 90°, or may be set according to actual conditions.
  • the other preset phase shift values are not limited to 90°.
  • the asymmetric coupling module may be a directional coupler or a multimode interferometer (English full name: Multimode Interference, English abbreviation: MMI), where the directional coupler is used as an asymmetry.
  • MMI Multimode Interference
  • the coupling module is introduced.
  • Similar effects can be achieved by using MMI. Therefore, MMI will not be repeated here.
  • FIG. 7 is a schematic structural diagram of a modulator in the embodiment of the present invention.
  • the directional coupler in the figure replaces the multimode interferometer to introduce a phase shift, and then the synthesis module synthesizes the modulation curve.
  • the laser is turned on, and the data is input to the modulator through the positive and negative electrodes respectively.
  • the positive electrode conducts a forward voltage, and the forward voltage is V/(2*V pi ), which obtains the traditional Mach-Zehnder high-low voltage modulation curve.
  • a transmission curve, the negative pole conducts a negative voltage, and the negative voltage magnitude is V/V pi .
  • the traditional Mach-Zehnder high-low voltage modulation curve is also obtained, which is the second transmission curve.
  • the phase shift is respectively performed, the forward voltage coefficient is 1, the corresponding phase shift is cos(phi), the negative voltage coefficient is ⁇ , and the corresponding phase shift is -sin(2*phi)/2.
  • the first transmission curve and the second transmission curve are phase-shifted and superimposed to obtain a transmission curve of the voltage at a V/V pi size.
  • V is the total voltage magnitude
  • V pi is the half-wave voltage magnitude
  • phi represents the golden section value: 0.618 (takes 3 significant digits). The meaning of these few characters will continue to be used in the following embodiments.
  • FIG. 8 is a comparative diagram of the light field transmission curve in the embodiment of the present invention, and the upper diagram of FIG. 8 is a Mach-Zehnder device in the cascade.
  • the modulation curve is shown, and the curve No. 1 in the figure is a curve obtained by modulation of a conventional modulator, and the curve No. 2 is a curve obtained by modulation of a modulator in the scheme of the present invention.
  • the No. 2 curve is actually formed by superimposing the modulation curves output by the two MZM devices, and the two MZM devices are designed to maintain the same design structure, but the output voltage is different.
  • the V pi of the MZM device connected to the forward voltage should be twice the V pi of the MZM device connected to the negative voltage. Therefore, the transmission curve period of the two is also twice the relationship, that is, the first transmission curve period is the second transmission curve.
  • the synthesis uses a directional coupler to introduce a 90° phase shift, and as can be seen from Figure 8, the transmission curve tends to be more straight when ⁇ is close to 0.18, and ⁇ is the specific light field intensity ratio.
  • the lower part of Fig. 8 is the absolute value function of the light field transmission curve.
  • the curve No. 1 in the figure is the curve obtained by the modulation of the traditional modulator, and the curve No. 2 is the curve obtained by the modulation of the modulator in the scheme of the present invention.
  • the absolute value function can also obtain the same conclusion, that is, the curve No. 2 is closer to a straight line, thereby further supporting the transmission curve obtained by the above method to be more excellent.
  • a modulator structure provided by the solution of the present invention adopts a MZM device cascading method to synthesize a transmission curve superposition by cascading two M pis in a multiple relationship of V pi and a specific light field intensity ratio (1:0.18).
  • the transmission curve becomes a linear transfer function.
  • an asymmetric coupling module is introduced in the modulator, and the asymmetric coupling module may be a directional coupler or an MMI.
  • the asymmetric coupling module is mainly used to add a phase shift, so that the composite transmission is performed. Before the curve, the phase adjustment of the first transmission curve obtained in advance can be combined with the second transmission curve more quickly and accurately to avoid phase difference. The resulting transmission curve does not achieve the desired results.
  • the use of asymmetric coupling module can improve the practicability and feasibility of the scheme, and the directional coupler in the asymmetric coupling module is similar to the function of the multimode interferometer. In practical applications, the appropriate instrument can be selected according to the needs, and the scheme is varied. Sex.
  • FIG. 9 is a high-order implementation in the embodiment of the present invention.
  • FIG. 9 A schematic diagram of another embodiment of a modulated modulator, the modulator 100 further comprising a first phase shifting module 105 and a first attenuation module 106;
  • the first phase shifting module 105 is configured to perform phase adjustment on the first transmission curve and the second transmission curve, and obtain an adjusted first transmission curve and an adjusted second transmission curve, so that The synthesizing module superimposes the adjusted first transmission curve and the adjusted second transmission curve on a phase to obtain a synthesized linear result;
  • the first attenuation module 106 is configured to control a scale ratio of the adjusted first transmission curve and the adjusted second transmission curve to pre-compensate the linear result according to the curve proportional size And output the linear result after pre-compensation.
  • the first phase shifting module may be introduced, and the main function thereof is to adjust the phase of the first transmission curve and the second transmission curve.
  • the adjustment method is that the first transmission curve is phase-shifted, or the second transmission curve is phase-shifted, and both phases can be simultaneously offset, and the specific offset angle is actually.
  • the situation is set and is not limited here.
  • the synthesis module superimposes the adjusted first transmission curve and the second transmission curve on the phase to obtain the desired linear result, and the linear result is the most linear part of the transmission curve.
  • the synthesizing module may also superimpose the phase of the first transmission curve and the adjusted second transmission curve, or superimpose the phase of the adjusted first transmission curve and the adjusted second transmission curve. The specific situation is adjusted according to actual needs.
  • a first attenuation module can be introduced, and the first attenuation module is configured to control a curve ratio of the modulated first transmission curve and the adjusted second transmission curve, and the curve can be adjusted after adding the first attenuation module.
  • the shape is pre-compensated according to the linear result obtained by the first phase shifting module described above, and a more linear result which tends to be straight can be obtained.
  • FIG. 10 is another schematic structural diagram of a modulator in an embodiment of the present invention.
  • a phase shifter and an attenuator may be introduced, and the phase shifter is used for a large
  • the phase of the first transmission curve and the second transmission curve are modulated, and the attenuator is a small amplitude pre-compensation of the synthesized transmission curve.
  • the laser is turned on, and the data is input to the modulator through the positive and negative electrodes respectively.
  • the positive electrode conducts a forward voltage, and the forward voltage is V/(2*V pi ), which obtains the traditional Mach-Zehnder high-low voltage modulation curve.
  • the traditional Mach-Zehnder high-low voltage modulation curve is also obtained, which is the second transmission curve.
  • the two transmission curves first pass through the MZM device. Then the phase shifter moves the two curves in phase, so that the initial phase of the superposition is consistent, the phase shift corresponding to the forward voltage is cos(phi), and the phase shift corresponding to the negative voltage is -sin(2*phi)/ 2, through the first transmission curve and the second transmission curve phase shift and superposition, the transmission curve of the voltage at V/V pi can be obtained, but the transmission curve can also be more linear, in this case, an attenuator is needed.
  • the obtained transmission curve is pre-compensated, and the linear result is obtained by controlling the ratio of the two optical fields.
  • FIG. 11 is another comparative diagram of the light field transmission curve in the embodiment of the present invention, and the upper diagram of FIG. 11 is a cascade of Mach-Zehnder.
  • the device modulates the curve, and the curve No. 1 in the figure is a curve obtained by modulation of a conventional modulator, and the curve No. 2 is a curve obtained by modulation of a modulator in the scheme of the present invention.
  • the No. 2 curve is actually formed by superimposing the modulation curves output by the two MZM devices, and the two MZM devices are designed to maintain the same design structure, but the output voltage is different.
  • the V pi of the MZM device connected to the forward voltage should be twice the V pi of the MZM device connected to the negative voltage. Therefore, the transmission curve period of the two is also twice the relationship, that is, the first transmission curve period is the second transmission curve.
  • the phase shifter is used for phase control, and the attenuator controls the ratio of the two light fields.
  • the transmission curve can pre-compensate the received signal when ⁇ is close to 0.4.
  • the transmission curve is more linear, and ⁇ is a specific light field intensity ratio.
  • the lower part of Fig. 11 is the absolute value function of the light field transmission curve.
  • the curve No. 1 in the figure is the curve obtained by the modulation of the traditional modulator, and the curve No. 2 is the curve obtained by the modulation of the modulator in the scheme of the present invention.
  • the absolute value function can also get the same conclusion, that is, the linear effect of the curve No. 2 is more obvious.
  • a modulator structure provided in the solution of the present invention adopts a MZM device cascading method to synthesize a transmission curve superposition by cascading two M pis in a multiple relationship of V pi and a specific light field intensity ratio (1:0.4).
  • the transmission curve precompensates the nonlinear device.
  • a phase shifter and an attenuator are introduced in the modulator to adjust the modulation curve of the modulator modulation, thereby increasing flexibility, and performing phase adjustment only for the first transmission curve.
  • two or more transmission curves can be adjusted to achieve a better synthesis.
  • Adding an attenuator to the modulator enables pre-compensation of peripheral electrical devices, suitable for multi-level modulation scenarios and high-order modulation scenarios, enhancing the practicality and feasibility of the solution.
  • the modulator further includes a third modulation module and a second phase shift module. And a second attenuation module;
  • the third modulation module is configured to receive third to-be modulated data, and output a third transmission curve according to the third to-be-modulated data, where a period of the third transmission curve is a period of the second transmission curve One-half;
  • the second phase shifting module is configured to perform phase adjustment on the first transmission curve, the second transmission curve, and the third transmission curve, and obtain the adjusted first transmission curve, the Tune a second transmission curve and an adjusted third transmission curve, so that the synthesis module sets the adjusted first transmission curve, the adjusted second transmission curve, and the adjusted third transmission curve Perform superposition on the phase to obtain a linear result after synthesis;
  • the second attenuation module is configured to control a scale ratio of the adjusted first transmission curve, the adjusted second transmission curve, and the adjusted third transmission curve to be proportional to the scale of the curve
  • the linear result is pre-compensated and the pre-compensated linear result is output.
  • FIG. 12 is another schematic structural diagram of a modulator in an embodiment of the present invention.
  • Three MZM devices are taken as an example for description. In practical applications, the modulation of three MZM devices is not limited. Device.
  • the laser is turned on, and the data is input to the three receiving modules respectively, the first modulation module receives the first to-be-modulated data, and outputs a first transmission curve according to the first to-be-modulated data, and the second modulation module receives the second to-be-modulated data, and according to The second to-be-modulated data outputs a second transmission curve, the period of the second transmission curve is one-half of the period of the first transmission curve, and the newly added third modulation module receives the third modulation data, and according to the third to-be-modulated data A third transmission curve is output, wherein the period of the third transmission curve is one-half of the period of the second transmission curve.
  • the second phase shifting module adjusts the phase of the three phases. It can be understood that the design of the second phase shifting module and the first phase shifting module The structure is basically the same and does not require redesign. After the phase adjustment of the second phase shifting module, the adjusted first transmission curve, the adjusted second transmission curve, and the adjusted third transmission curve are obtained, and the three transmission curves are the same in the initial phase, The synthesis module can superimpose the three transmission curves on the phase to obtain the synthesized linear result.
  • the first transmission curve is obtained under the condition that the voltage is V/(4*V pi ), and the modulation curve expression is obtained as The corresponding phase shift is cos(phi).
  • the second transmission curve is obtained under the condition that the voltage is V/(2*V pi ), and the modulation curve expression is obtained as The corresponding phase shift is -sin(2*phi)/2.
  • the third transmission curve is obtained under the condition that the voltage is V/(V pi ), and the modulation curve expression is obtained as The corresponding phase shift is -sin(4*phi)/2.
  • the synthesizing module can superimpose the three transmission curves on the phase to obtain the synthesized linear result, and then control the adjusted first transmission curve, the adjusted second transmission curve, and the adjusted third by the second attenuation module.
  • the scale of the curve of the transmission curve to the previous stage according to the scale of the curve The resulting linear result is pre-compensated and the linear result after pre-compensation is output.
  • the compensated linear result will tend to be more linear.
  • a modulator structure provided in the solution of the present invention adopts a MZM device cascading method to synthesize a transmission curve superposition by cascading three M pis of multiple V pi and a specific light field intensity ratio (1:0.12).
  • the transmission curve becomes a linear transfer function.
  • a modulator capable of superimposing and synthesizing a plurality of transmission curves, and the periods of the plurality of transmission curves should be in a multiple relationship.
  • the phase adjustment of the second phase shifting module is performed by using multiple transmission curves, and the second attenuation module precompensates the synthesized transmission curve, so that the modulation curve of the modulator output is more linearized, and at the same time, multiple transmission curves are performed.
  • the linear results obtained after superposition are also more refined.
  • the first modulation module is connected to the first phase shift module
  • the first phase shifting module is connected to the first attenuation module by the second modulation module.
  • FIG. 13 is another schematic structural diagram of a modulator in an embodiment of the present invention. Two MZM devices are taken as an example for description. In practical applications, the modulation of three MZM devices is not limited. Device.
  • the laser is turned on, and the data is input to the two receiving modules respectively, the first modulation module receives the first data to be modulated, and outputs a first transmission curve according to the first data to be modulated, and the second modulation module receives the second data to be modulated, and according to The second data to be modulated outputs a second transmission curve, and the period of the second transmission curve is one-half of the period of the first transmission curve.
  • the first modulation module is connected to the first phase shifting module, and the first phase shifting module can directly perform phase shifting on the first transmission curve output by the first modulation module, and input from the negative voltage.
  • the data is first pre-compensated by the first attenuation module, and then the second data to be modulated after the compensation is input to the second modulation module, and the second modulation module obtains the second to be modulated according to the compensation.
  • the data outputs a second transmission curve.
  • the phase-shifted first transmission curve is superimposed with the second transmission curve to synthesize the modulated transmission curve.
  • control point needs to be optimized. Specifically, the control point can also be considered as the part of the received signal. To obtain more accurate data, it is necessary to The received signal is amplified to achieve the best results.
  • a modulator structure which can superimpose and synthesize a plurality of transmission curves, and perform phase adjustment on the first transmission curve by using the first phase shifting module.
  • the second transmission curve is pre-compensated by the first attenuation module to obtain a more linear curve.
  • the solution of the invention changes the parallel cascade into a serial cascade to form another transmission curve adjustable modulation.
  • the structure of the modulator makes the modulator structure more diversified, which is convenient for design and application, and improves the feasibility of the scheme.
  • a system for implementing high-order modulation includes two or more modulators, and the modulator is the first embodiment corresponding to FIG. 5 and the first corresponding to FIG.
  • the structure of the modulator is further optimized, that is, a system for realizing high-order modulation is obtained by cascading a plurality of modulators, and the data can be directly optimized in stages, that is, Each modulator optimizes the data separately to obtain a more linear modulation curve.
  • FIG. 14 is a modulation structure of dual polarization quadrature phase shift keying/quadrature amplitude modulation according to an embodiment of the present invention.
  • the laser is turned on, and the light passes through the polarization beam splitter to obtain two different vibration directions.
  • the light is separated.
  • the system for implementing high-order modulation includes a plurality of modulators, which are superimposed in-phase quadrature (English name: in-phase quadrature, English abbreviation: IQ) modulator architecture, IQ modulation is data divided into two, respectively Carrier modulation is performed, and the two carriers are orthogonal to each other.
  • IQ modulation is the direction problem of the vector.
  • the in-phase is the same signal in the vector direction.
  • the orthogonal component is the orthogonality of the two signal vectors (90° difference); the IQ signal is 0° and 180° all the way, and the other is 90° and 270°. They are called I and Q, respectively, and they are two orthogonal signals.
  • Each IQ modulator architecture is a combination of two or more modulators. After receiving the data, the IQ modulator architecture also uses the modulator output mentioned in the above embodiment to linearize the transmission.
  • the curves are similar, that is, two or more transmission curves are received, and a modulated transmission curve is synthesized by controlling the phase shift and the control of the light field ratio, and the curve tends to be more linear.
  • the IQ modulator architecture outputs the modulated transmission curve to the combined polarizer in the X-axis and Y-axis directions, and synthesizes the X-axis and Y-axis transmission curves through a combined polarizer, and obtains a modulated signal.
  • a modulation system composed of a plurality of modulator combinations
  • the structure of the modulator is optimized in one step, the signal is directly segmented, and the modulation of various patterns is realized by the IQ modulator architecture superimposed by the modulator, thereby enhancing the flexibility of the scheme and being used for achieving higher order. Modulation of the pattern.
  • the embodiment of the present invention reduces the dependence on digital signal processing, directly performs partial signal processing on the optical path, and improves signal quality.
  • FIG. 15 is a schematic diagram of implementing high-order modulation according to an embodiment of the present invention.
  • a schematic flowchart of a method, wherein the method method for implementing high-order modulation may include:
  • Receive first data to be modulated and output a first transmission curve according to the first data to be modulated.
  • the modulator for implementing high-order modulation receives the first data to be modulated under the control of the positive voltage, and outputs the first data to be modulated to obtain a corresponding first transmission curve, and the first transmission
  • the curve is sinusoidal.
  • Receive second information to be modulated and output a second transmission curve according to the second data to be modulated, where a period of the second transmission curve is one-half of a period of the first transmission curve;
  • the modulator for implementing high-order modulation receives the second data to be modulated under the control of the negative voltage, and outputs the second data to be modulated to obtain a corresponding second transmission curve.
  • the second The transmission curve is also sinusoidal. However, since there is a voltage difference between the positive voltage and the negative voltage, the negative voltage is half of the positive voltage, and thus the period of the obtained second transmission curve is one-half of the period of the first transmission curve.
  • the modulator superimposes the first transmission curve and the second transmission curve in phase, thereby synthesizing the linear result.
  • the specific method of synthesizing the two curves is similar to the one described in the embodiment corresponding to FIG. 3 above, and therefore will not be described again here.
  • a method for implementing high-order modulation is provided.
  • the controller modulates the received first to-be-modulated data and the second to-be-modulated data, and outputs a corresponding first transmission curve and a second transmission curve.
  • the second transmission curve is in a multiple relationship with the first transmission curve, and the two transmission curves are superimposed in phase to obtain a desired linear result.
  • the modulator can obtain a modulatable linear result by controlling the superposition ratio between the transmission curves, thereby realizing the transmission of the linear curve, which is suitable for various adjustments. System scenarios to enhance the flexibility of the solution.
  • the first transmission curve and the second transmission curve are phased on the basis of the foregoing embodiment corresponding to FIG. Before the overlay, you can also include:
  • the first transmission curve after the offset is superimposed on the phase with the second transmission curve to obtain a linear result after the synthesis.
  • the first transmission curve needs to be phase-shifted, and the offset may be 90°, or may be set according to actual conditions.
  • the other preset phase shift values are not limited to 90°.
  • the offset first transmission curve and the second transmission curve may be superimposed in phase to synthesize the modulated transmission curve.
  • a method for adding a phase shift in a modulator is provided, so that the phase adjustment of the first transmission curve obtained before the synthesis of the transmission curve can be performed more quickly and accurately.
  • the second transmission curve is combined in phase to avoid the synthetic transmission curve not achieving the expected effect due to the difference in phase, thereby improving the practicability and feasibility of the solution, and in practical applications, the appropriate instrument can be selected according to the needs, The diversity of the program.
  • the first transmission curve and the second transmission curve are phased on the basis of the foregoing embodiment corresponding to FIG. 15 .
  • the ratio of the adjusted first transmission curve to the adjusted second transmission curve is controlled to pre-compensate the linear result according to the scale of the curve, and output the linear result after pre-compensation.
  • the first transmission curve and the second transmission curve may be adjusted in phase, and the adjustment method is: the first transmission curve Perform phase shifting, or phase shifting the second transmission curve. You can also phase shift both of them at the same time.
  • the specific offset angle is set according to the actual situation. .
  • the modulator superimposes the adjusted first transmission curve and the second transmission curve in phase to obtain a desired linear result, and the linear result is the most linear part of the transmission curve.
  • the first transmission curve and the adjusted second transmission curve may be superimposed in phase, or the adjusted first transmission curve and the adjusted second transmission curve may be superimposed in phase.
  • the specific situation is adjusted according to actual needs.
  • optical power in the system channel is deliberately kept low, nonlinear damage can affect all long-haul optical transmission systems, and a more linear result can be obtained by pre-compensation. This is especially true for CO-OFDM technology systems with very high PAPR. Since the optical OFDM signal is superimposed by a series of subchannel signals, it is easy to make the time domain signal have a high PAPR. Compared with wireless communication systems, optical fiber communication systems are nonlinear media transmission. Because the spectral spacing between subcarriers in optical OFDM systems is small, this makes the separation effect between subcarriers weak, and it is easy to meet the nonlinear FWM interaction. The conditions that form crosstalk.
  • a method for adjusting a modulation curve modulated by a modulator is provided, thereby increasing flexibility, and the phase adjustment can be performed only for the first transmission curve. Two or more transmission curves are adjusted for better synthesis. Adding an attenuator to the modulator enables pre-compensation of peripheral electrical devices, suitable for multi-level modulation scenarios and high-order modulation scenarios, enhancing the practicality and feasibility of the solution.
  • the method may further include:
  • the adjusted first transmission curve, the adjusted second transmission curve, and the adjusted third transmission curve are proportional to the linear result, and the linear result is pre-compensated according to the scale of the curve, and the pre-compensated linear result is output.
  • the laser is first turned on, the data is input to the modulator, the first data to be modulated is received, and the first transmission curve is output according to the first data to be modulated, the second data to be modulated is received, and the data is output according to the second data to be modulated.
  • a second transmission curve the period of the second transmission curve is one-half of the period of the first transmission curve, receives the third modulation data, and outputs a third transmission curve according to the third to-be modulated data, wherein the third transmission curve The period is one-half of the period of the second transmission curve.
  • the three After obtaining the first transmission curve, the second transmission curve, and the third transmission curve, the three are adjusted in phase. After the phase adjustment, the adjusted first transmission curve, the adjusted second transmission curve, and the adjusted third transmission curve can be obtained.
  • the three transmission curves are the same in the initial phase, and the three transmission curves can be phased. Overlay on top to get a linear result after synthesis.
  • the linear result obtained in the previous stage is pre-compensated according to the scale of the curve, and the pre-compensation is output. Linear result.
  • the compensated linear result will tend to be more linear.
  • a method for superimposing and synthesizing a plurality of transmission curves is provided, and the periods of the plurality of transmission curves should be in a multiple relationship.
  • the modulation curve of the modulator output is more linear, and the linear results obtained by superimposing multiple transmission curves are more refined.
  • the first to-be-modulated data is received according to the second embodiment corresponding to FIG.
  • the method may further include:
  • the method may further include:
  • a curve applied to a plurality of periods in a modulator having a multiple relationship is superimposed, and a plurality of MZM devices in the modulator are changed from a parallel connection method to a serial connection, and a modification is made in the structure.
  • the laser is first turned on, the data is input to the modulator, the modulator receives the first data to be modulated, and outputs a first transmission curve according to the first data to be modulated, and simultaneously receives the second data to be modulated, and according to the second to be modulated.
  • the data outputs a second transmission curve whose period is one-half of the period of the first transmission curve.
  • the first transmission curve of the output can be directly moved in phase, and the data input by the negative voltage is pre-compensated, and then the second data to be modulated obtained after the compensation is output. A second transmission curve is obtained. Finally, the phase-shifted first transmission curve is superimposed with the second transmission curve to synthesize the modulated transmission curve.
  • control point needs to be optimized. Specifically, the control point can also be considered as the part of the received signal. To obtain more accurate data, the received signal needs to be received. Zoom in for the best results.
  • a method for implementing modulation which can superimpose and synthesize a plurality of transmission curves to perform phase adjustment on the first transmission curve.
  • the second transmission curve is also pre-compensated to obtain a more linear curve.
  • the solution of the invention changes the parallel cascade into a serial cascade to form another modulator structure with adjustable transmission curve, so that modulation
  • the structure of the device is more diversified, which is convenient for design and application, and improves the feasibility of the solution.
  • the disclosed system, apparatus, and method may be implemented in other manners.
  • the device embodiments described above are merely illustrative.
  • the division of the unit is only a logical function division, and the actual implementation may have another
  • the manner of division, such as multiple units or components, may be combined or integrated into another system, or some features may be omitted or not performed.
  • the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.
  • each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.
  • the above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.
  • the integrated unit if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium.
  • the technical solution of the present invention which is essential or contributes to the prior art, or all or part of the technical solution, may be embodied in the form of a software product stored in a storage medium.
  • a number of instructions are included to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention.
  • the foregoing storage medium includes: a U disk, a mobile hard disk, a read only memory (English full name: Read-Only Memory, English abbreviation: ROM), a random access memory (English full name: Random Access Memory, English abbreviation: RAM), magnetic A variety of media that can store program code, such as a disc or a disc.

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Abstract

本发明实施例公开了一种调制器，包括：第一调制模块，用于接收第一待调制数据，并根据第一待调制数据输出第一传输曲线；第二调制模块，用于接收第二待调制数据，并根据第二待调制数据输出第二传输曲线，其中，第二传输曲线的周期为第一传输曲线的周期的二分之一；合成模块，用于将第一传输曲线与第二传输曲线进行相位上的叠加，以得到合成后的线性结果。此外，本方案还提供了一种调制系统以及实现高阶调制的方法，可以通过控制传输曲线之间的叠加比例得到可调制的线性结果，从而实现线性曲线的传输，适用于多种调制场景，增强方案的灵活性。

Description

一种调制器、调制系统以及实现高阶调制的方法 技术领域
本发明涉及通信领域中的信号调制，尤其涉及一种调制器、调制系统以及实现高阶调制的方法。
背景技术
移动通信网消息随着数据通信及互联网络的高速发展，网络点到点、在线应用及视频业务都呈现出爆炸式增长，海量数字媒体内容已经引发了互联网流量出现十倍甚至百倍的急速增长，目前传输速度为每秒100000兆位(即100Gbps)系统已经在各大运营商商用，400G系统能够在100G的基础上进一步提升网络容量并降低每比特传输成本，有效地解决运营商面临的业务流量及网络带宽持续增长的压力。
100G系统采用的正交相移键控(英文全称：quadrature phase shift keying，英文缩写：QPSK)调制技术，相干检测技术以及数字信号处理(英文全称：digital signal processing，英文缩写：DSP)技术把系统的光信噪比(英文全称：Optical Signal Noise Ratio，英文缩写：OSNR)容限降低到10G相同量级，降低了系统对光纤的要求。
400G系统带来的OSNR受限和噪声及非线性等问题，对传输距离会产生限制，从目前主流设备采用双载波和正交幅度调制(英文全称：quadrature amplitude modulation，英文缩写：16QAM)调制技术的400G系统的传输距离只有100G系统的1/3左右，因此高速率系统的建设需要综合考虑系统容量和传输距离要求。
现有技术中提供了一种基于铌酸锂(英文全称：lithium niobate，英文缩写：LiNbO3)器件实现QPSK和偏振分多路复用正交相移键控(英文全称：polarization division multiplexed quaternary phase shift keying，英文缩写：PDM-QPSK)。请参阅图1，图1为现有技术中实现QPSK和PDM-QPSK的架构示意图。使用该调制架构可以得到正弦式的调制曲线。
然而，由于调制曲线为正弦式曲线，在用于例如16QAM等高阶调制时，需要数字模拟转换器(英文全称：digital to analog converter，英文缩写：DAC)进行非线性补偿，这样会加大数字信号处理器(英文全称：digital signal  processor，英文缩写：DSP)的补偿功耗与芯片规模，尤其在进行高阶调制的情况下，所需要的补偿功耗和芯片规模将更大。
发明内容
本发明实施例提供了一种调制器、调制系统以及实现高阶调制的方法，可以通过控制传输曲线之间的叠加比例得到可调制的线性结果，从而实现线性曲线的传输，适用于多种调制场景，增强方案的灵活性。
本发明实施例第一方面提供了一种调制器，包括：
第一调制模块，用于接收第一待调制数据，并根据所述第一待调制数据输出第一传输曲线；
第二调制模块，用于接收第二待调制数据，并根据所述第二待调制数据输出第二传输曲线，其中，所述第二传输曲线的周期为所述第一传输曲线的周期的二分之一；
合成模块，用于将所述第一传输曲线与所述第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
结合本发明实施例的第一方面，在第一种可能的实现方式中，所述调制器还包括非对称耦合模块；
所述非对称耦合模块，用于为所述第一传输曲线增加预置相移值，得到偏移后的第一传输曲线；
所述合成模块，还用于将所述偏移后的第一传输曲线与所述第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
结合本发明实施例的第一方面，在第二种可能的实现方式中，所述调制器还包括第一相移模块以及第一衰减模块；
所述第一相移模块，用于对所述第一传输曲线与所述第二传输曲线进行相位的调整，并得到调整后的第一传输曲线与调整后的第二传输曲线，以使所述合成模块将所述调整后的第一传输曲线与所述调整后的第二传输曲线进行相位上的叠加，以得到合成后的线性结果；
所述第一衰减模块，用于控制所述调整后的第一传输曲线与所述调整后的第二传输曲线的曲线比例大小，以根据所述曲线比例大小对所述线性结果进行预补偿，并输出预补偿后的线性结果。
结合本发明实施例的第一方面，在第三种可能的实现方式中，所述调制器还包括第三调制模块、第二相移模块以及第二衰减模块；
所述第三调制模块，用于接收第三待调制数据，并根据所述第三待调制数据输出第三传输曲线，其中，所述第三传输曲线的周期为所述第二传输曲线的周期的二分之一；
所述第二相移模块，用于对所述第一传输曲线、所述第二传输曲线以及所述第三传输曲线进行相位的调整，并得到所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线，以使所述合成模块将所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线进行相位上的叠加，以得到合成后的线性结果；
所述第二衰减模块，用于控制所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线的曲线比例大小，以根据所述曲线比例大小对所述线性结果进行预补偿，并输出预补偿后的线性结果。
结合本发明实施例的第一方面第二种可能实现方式，在第四种可能的实现方式中，所述第一调制模块与所述第一相移模块相连，所述第一相移模块通过所述第二调制模块与所述第一衰减模块相连。
本发明实施例第二方面提供了一种实现高阶调制的系统，包括：所述系统包括至少一个调制器；
所述调制器如本发明第一方面，以及第一方面第一至第四种可能实现方式中任意一项所述的调制器。
本发明实施例第三方面提供了一种实现高阶调制的方法，其特征在于，包括：
接收第一待调制数据，并根据所述第一待调制数据输出第一传输曲线；
接收第二待调制数据，并根据所述第二待调制数据输出第二传输曲线，其中，所述第二传输曲线的周期为所述第一传输曲线的周期的二分之一；
将所述第一传输曲线与所述第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
结合本发明实施例的第三方面，在第一种可能的实现方式中，所述将所述第一传输曲线与所述第二传输曲线进行相位上的叠加之前，所述方法还包括：
为所述第一传输曲线增加预置相移值，得到偏移后的第一传输曲线，以使所述偏移后的第一传输曲线与所述第二传输曲线进行相位上的叠加。
结合本发明实施例的第三方面，在第二种可能的实现方式中，所述将所述第一传输曲线与所述第二传输曲线进行相位上的叠加之前，所述方法还包括：
对所述第一传输曲线与所述第二传输曲线进行相位的调整，并得到调整后的第一传输曲线与调整后的第二传输曲线，以使所述调整后的第一传输曲线与所述调整后的第二传输曲线进行相位上的叠加；
控制所述调整后的第一传输曲线与所述调整后的第二传输曲线的曲线比例大小，以根据所述曲线比例大小对所述线性结果进行预补偿，并输出预补偿后的线性结果。
结合本发明实施例的第三方面，在第三种可能的实现方式中，所述接收第二待调制数据，并根据所述第二待调制数据输出第二传输曲线之后，所述方法还包括：
接收第三待调制数据，并根据所述第三待调制数据输出第三传输曲线，其中，所述第三传输曲线的周期为所述第二传输曲线的周期的二分之一；
对所述第一传输曲线、所述第二传输曲线以及所述第三传输曲线进行相位的调整，并得到所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线，以将所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线进行相位上的叠加；
控制所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线的曲线比例大小，以根据所述曲线比例大小对所述线性结果进行预补偿，并输出预补偿后的线性结果。
结合本发明实施例的第三方面第二种可能实现方式，在第四种可能的实现方式中，所述接收第一待调制数据，并根据所述第一待调制数据输出第一传输曲线之后，所述方法还包括：
对所述第一传输曲线进行相位的调整；
所述接收第二待调制数据，并根据所述第二待调制数据输出第二传输曲线之后，所述方法还包括：
控制所述调整后的第一传输曲线与所述第二传输曲线的曲线比例大小。
从以上技术方案可以看出，本发明实施例具有以下优点：
本发明实施例中，提供了一种实现高阶调制的调制器，该调制器可以对接收到的第一待调制数据以及第二待调制数据进行调制，并输出对应的第一传输曲线和第二传输曲线，其中，第二传输曲线与第一传输曲线的周期呈倍数关系，将两条传输曲线进行相位上的叠加，得到需要的线性结果。调制器通过对第一传输曲线和第二传输曲线进行相位上的叠加，来实现线性曲线的传输，适用于多种调制场景，增强方案的灵活性。同时，上述过程可以不需要在进行高阶调制的情况下，额外使用数字模拟转换器来完成非线性补偿，可以减小数字信号处理器的补偿功耗与芯片规模。
附图说明
为了更清楚地说明本发明实施例的技术方案，下面将对实施例描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为现有技术中实现QPSK和PDM-QPSK的架构示意图；
图2为本发明实施例中一种传输曲线的示意图；
图3为本发明实施例理论仿真中的一个调制器结构示意图；
图4为本发明实施例中调制器输出的调制曲线与传统调制器输出的调制曲线对比示意图；
图5是本发明实施例中实现高阶调制的调制器一个实施例示意图；
图6是本发明实施例中实现高阶调制的调制器另一个实施例示意图；
图7是本发明实施例中调制器的一个结构示意图；
图8是本发明实施例中光场传输曲线一个对比示意图；
图9是本发明实施例中实现高阶调制的调制器另一个实施例示意图；
图10是本发明实施例中调制器的另一个结构示意图；
图11是本发明实施例中光场传输曲线另一个对比示意图；
图12是本发明实施例中调制器的另一个结构示意图；
图13是本发明实施例中调制器的另一个结构示意图；
图14是本发明实施例中双偏振正交相移键控/正交振幅调制的一个调制结 构；
图15为本发明实施例中实现高阶调制的方法一个实施例示意图。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
本发明的说明书和权利要求书及上述附图中的术语“第一”、“第二”、“第三”“第四”等(如果存在)是用于区别类似的对象，而不必用于描述特定的顺序或先后次序。应该理解这样使用的数据在适当情况下可以互换，以便这里描述的本发明的实施例例如能够以除了在这里图示或描述的那些以外的顺序实施。此外，术语“包括”和“具有”以及他们的任何变形，意图在于覆盖不排他的包含，例如，包含了一系列步骤或单元的过程、方法、系统、产品或设备不必限于清楚地列出的那些步骤或单元，而是可包括没有清楚地列出的或对于这些过程、方法、产品或设备固有的其它步骤或单元。
本发明实施例提供了一种调制器、调制系统以及实现高阶调制的方法，可以通过控制传输曲线之间的叠加比例得到可调节的线性结果，从而实现线性曲线的传输，适用于多种调制场景，增强方案的灵活性，请参阅图1至图15。下面通过具体实施例，分别进行详细的说明。
应理解，本发明实施例提供的调制器可以应用于移动互联网、云计算和互联网等高速光传输技术。随着通信业务的飞速发展，促进网络对大带宽调度的需求产生，本实施例中，将以100Gb/s高速光传输系统为例进行介绍，然而，在实际应用中，并不仅限于100Gb/s高速光传输系统，还可以是400Gb/s高速光传输系统等其他系统。
核心网路由器互联成为40Gb/s的关键驱动力，推动了骨干网密集型光波复用(英文全称：Dense Wavelength Division Multiplexing，英文缩写：DWDM)传输系统的40Gb/s的调制码型技术发展。40Gb/s能够更好地满足网际互联协议(英文全称：Internet Protocol，英文缩写：IP)宽带业务流量增长的需求，具有更高的集成度，节省空间、电量以及运行维护成本等方面的优势。然而 40bit/s DWDM传输系统与10Gb/s传输在同等物联条件下相比，光信噪比(英文全称：Optical Signal Noise Ratio，英文缩写：OSNR)劣化4倍，色度色散容量降低16倍，偏振模色散(英文全称：Polarization Mode Dispersion，英文缩写：PMD)劣化4倍，且非线性效应更加明显。因此，为了提升传输性能，并降低OSNR、PMD、非线性以及色散等各方面的限制，应用先进的调制码型成为了传输的关键技术之一。下面将介绍三种主流的调制码型。
一、差分相移键控(英文全称：Differential Phase Shift Keying，英文缩写：DPSK)；
光纤传输系统中广泛使用的调制格式为基于幅度的开关键控调制(英文全称：On-Off Keying，英文缩写：OOK)，采用直接检测的方式进行接收。基于相位的DPSK调制与传QPSK的基础上引入预啁啾技术来改善非线性容限。预啁啾用于抵消脉冲本身因发射和传播过程中产生的啁啾，达到压缩脉冲的效果，延长传输距离，提升传输性能。
二、四相相对相移键控(英文全称：Differential Quadrature Reference Phase Shift Keying，英文缩写：DQPSK)；
DQPSK调制码型有延迟差分接收和相干接收，差分接收性能逊于相干接收。相干接收使用QPSK调制码型，该QPSK调制码型利用载波的四种不同相位来表征数字信息。由于每一种载波相位代表两个比特信息，故每个四进制码元又被称为双比特码元。把组成双比特码元的前一信息比特用a代表，后一信息比特用b代表。双比特码元中两个信息比特ab通常是按格雷码，即反射码排列的，双比特码元与载波相位的关系如下表所示：
表1
Figure PCTCN2015094119-appb-000001
由于四相绝对移相调制可以看作两个正交的二相绝对移相调制的合成，故 两者的功率谱密度分布规律相同。
三、双偏振差分正交相移键控(英文全称：Double Polarization Quadrature Reference Phase Shift Keying，英文缩写：DP-QPSK)；
DP-QPSK通过偏振复用的DQPSK调制码型，或称双极化QPSK，即用2个正交的偏振态传输2路不同信息，尽管频率相同，但由于它们的极性相差90°，因此不会互相影响，频谱效率相较于DQPSK提高1倍，变成每1个符号传输4个比特，因而可以获得与传统10Gb/s非归零开关键制(英文全称：Non-Return to Zero On-Off Keying，英文缩写：NRZ-OOK)传输系统类似的噪声特性。通过偏振复用和差分正交相移键以将线路速率减少到10G波特，电子和电光器件的带宽要求大大降低，便于实现数字信号处理，在电域实现大范围色度色散和PMD补偿。DP-QPSK调制码型信号采用偏振分集和数字相干接收技术，使信号光通过一个偏振分束器(英文全称：Polarizing beam splitter，英文缩写：PBS)分解成两个正交偏振信号，每个正交偏振信号都与一个本地光源混频，该本地光源的载波频率控制精度为几百千赫兹(英文全称：kilohertz，英文缩写：kHz)。混频后得到4个极化和相位正交的光信号，分别用平衡检测接收，经电放大和滤波后由模数单仪器模数转换(英文全称：Analog to Digital Converter，英文缩写：A/D)电路转换为4路数字信号，在电域实现偏振分离，消除相位畸变、色散、偏振模色散和非线性效应的补偿均衡等一体化处理。
本发明实施例中，主要针对非线性效应的补偿设计一种调制器，可以通过控制传输曲线之间的叠加比例得到可调制的线性结果，从而实现线性曲线的传输，应理解，本发明方案提出的一种新型调制器结构，采用马赫-曾德尔调制器(英文全称：Mach-Zehnder modulator，英文缩写：MZM)器件级联的方式进行传输曲线的合成。其中，MZM器件的半波电压Vpi成倍数关系，级联的方式可以是并行连接或者串行连接。以不同光场强比来合成信号，并且通过控制MZM之间的分光比来控制曲线合成的形状，实现传输曲线可调节。
与传统调制器调制出的曲线相比，本发明方案所获得的传输曲线更接近线性化，即线性效应更加明显。请参阅图2，图2为本发明实施例中一种传输曲线的示意图。如图所示，在MZM器件级联的情况下得到对应的输出曲线，假设归一化场强因子γ＝0.18，图中1号曲线为传统调制器调制出的传输曲线， 该传输曲线呈正弦型，光场随着分光比的减少而减小。2号曲线则是本发明实施例调制后得到的传输曲线，与1号曲线相比，更趋于线性化，且光场仍然随着分光比的减少而减小。
本实施例中通过理论仿真的方法可以获取图2对应的2号曲线，具体地，请参阅图3，图3为本发明实施例理论仿真中的一个调制器结构示意图。图中的P为正向电压，N则为负向电压，其中，正电压等于两倍的负电压，即Vpi_upper＝2Vpi_lower，Vpi为半波电压。半波电压是指光波在光晶体中传播时，当光波的两个垂直分量Ex’与Ey’的光程差为半个波长时(即，对应的相位差为180度)所需要加的电压。图3以定向耦合器取代锁模激光器(英文全称Mode-locked laser，英文缩写：MLL)引入相移的方法进行介绍，在实际应用中，也可以在正极电压输出端引入相移单元来输出调制曲线。图3中仅为将两个MZM器件级联后输出的曲线进行合成，然而，本发明实施例并不仅限于两个MZM器件级联，因此，输出的调制曲线也可以是由多条曲线叠加而成的。下面将对如何输出合成后的调制曲线进行介绍：
采用公式：
Figure PCTCN2015094119-appb-000002
其中，ψ(t)表示曲线与时间的函数，ψ0为电压为0时的光场初始值，j是虚数单位，ω0t为电压为0时的角度初始值，φa为在Vpi_upper电压下的偏移角度，φb为Vpi_lower电压下的偏移角度，且Vpi_upper＝2Vpi_lower。
分别将正负极电压对应的偏移角度代入公式中，得到负极电压处的曲线与时间函数为：
ψ(t)＝ψ0exp(jω0t)cos(Δφ/2)
正极电压处的曲线与时间函数为：
ψ(t)＝ψ0exp(jω0t)sin(-2·Δφ/2)
其中，-2·Δφ是在Vpi_upper＝2Vpi_lower时对应的角度差，具体地，该角度差可以为cos(-2·Δφ/2-90°)＝-sin(2·Δφ/2)
假设负极电压的电压系数为1，正极电压的电压系数为γ，将1代入上述函数ψ(t)＝ψ0exp(jω0t)cos(Δφ/2)，将正极电压电压系数γ代入上述函数ψ(t)＝ψ0exp(jω0t)sin(-2·Δφ/2)中，可以得到合成后的调制曲线函数，即为： ψ(t)＝ψ0exp(jω0t)[cos(Δφ/2)-γsin(2·Δφ/2)]。
请参阅图4，图4为本发明实施例中调制器输出的调制曲线与传统调制器输出的调制曲线对比示意图。在得到调制曲线之前，传统MZM高电压调制曲线的函数表达可以为ψ(t)＝ψ0exp(jω0t)sin(-2·Δφ/2)，而传统MZM低电压调制曲线的函数表达可以为ψ(t)＝ψ0exp(jω0t)cos(Δφ/2)。采用MZM器件级联的方式得到合成前的调制曲线ψ(t)＝ψ0exp(jω0t)cos(Δφ/2)，将传统MZM高电压调制曲线与传统MZM低电压调制曲线进行合成，得到调制后的曲线ψ(t)＝ψ0exp(jω0t)[cos(Δφ/2)-γsin(2·Δφ/2)]。
通过图4的调制曲线对比图可以得到，在传统的MZM高低电压下得到的调制曲线呈正弦型，而采用本发明方案使用的级联MZM器件时，可以将传统的MZM器件得到的调制曲线进行叠加，合成我们所需的调制曲线，并更趋于线性。
本发明实施例中，将具体对如何输出更趋于线性的调制曲线进行说明，请参与图5，图5为本发明实施例中实现高阶调制的调制器一个实施例示意图，实现高阶调制的调制器100，包括：
第一调制模块101，用于接收第一待调制数据，并根据所述第一待调制数据输出第一传输曲线；
第二调制模块102，用于接收第二待调制数据，并根据所述第二待调制数据输出第二传输曲线，其中，所述第二传输曲线的周期为所述第一传输曲线的周期的二分之一；
合成模块103，用于将所述第一调制模块101接收的所述第一传输曲线与所述第二调制模块102接收的所述第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
本实施例中，用于实现高阶调制的调制器具有三个模块，分别为第一调制模块、第二调制模块以及合成模块。其中，在正极电压控制下，第一调制模块接收第一待调制数据，并将第一待调制数据进行输出，得到对应的第一传输曲线，且第一传输曲线呈正弦型。在负极电压控制下，第二调制模块接收第二待调制数据，并输出第二待调制数据，得到对应的第二传输曲线，同样地，该第二传输曲线也呈正弦型，然而由于正极电压与负极电压之间具有电压差，负极 电压是正极电压的一半，因此所得到的第二传输曲线的周期为第一传输曲线的周期的二分之一。合成模块将第一传输曲线与第二传输曲线进行合成，合成的具体做法与上述3对应的实施例中介绍的方案类似，即为函数的叠加。
本发明实施例中，提供了一种实现高阶调制的调制器，该调制器可以对接收到的第一待调制数据以及第二待调制数据进行调制，并输出对应的第一传输曲线和第二传输曲线，其中，第二传输曲线与第一传输曲线呈倍数关系，将两条传输曲线进行相位上的叠加，得到需要的线性结果。调制器可以通过控制传输曲线之间的叠加比例得到可调制的线性结果，从而实现线性曲线的传输，适用于多种调制场景，增强方案的灵活性。
可选地，在上述图5对应的实施例的基础上，本发明实施例提供的调制器的第一个可选实施例中，请参阅图6，图6是本发明实施例中实现高阶调制的调制器另一个实施例示意图，所述调制器100还包括非对称耦合模块104；
所述非对称耦合模块104，用于为所述第一传输曲线增加预置相移值，得到偏移后的第一传输曲线；
所述合成模块103还用于将所述偏移后的第一传输曲线与所述第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
本实施例中，在合成模块对第一传输曲线与第二传输曲线进行叠加之前，需要对第一传输曲线进行相位上的偏移，偏移量可以为90°，也可以是根据实际情况设定的其他预置相移值，并不仅限于90°。在经过非对称耦合模块后，得到偏移后的第一传输曲线，使得合成模块可以将偏移后的第一传输曲线与第二传输曲线进行相位上的叠加，从而合成调制后的传输曲线。
需要说明的是，非对称耦合模块在实际应用中，可以是定向耦合器，也可以是多模干涉仪(英文全称：Multimode Interference，英文缩写：MMI)，此处将以定向耦合器作为非对称耦合模块进行介绍，然而使用MMI也可以达到类似效果，故此处不再以MMI为例进行赘述。
具体地，请参阅图7，图7是本发明实施例中调制器的一个结构示意图，图中的定向耦合器取代多模干涉仪引入相移，然后再由合成模块合成调制曲线。首先开启激光器，数据分别通过正极和负极输入到调制器，正极传导的是正向电压，正向电压大小为V/(2*Vpi)，得到传统马赫-曾德尔高低电压调制曲 线，即为第一传输曲线，负极传导的是负向电压，负向电压大小为V/Vpi，也得到传统马赫-曾德尔高低电压调制曲线，即为第二传输曲线，两条传输曲线在经过MZM器件后，分别对其进行相移，正向的电压系数为1，对应的相移为cos(phi)，负向的电压系数为γ，对应的相移为-sin(2*phi)/2，通过第一传输曲线与第二传输曲线进行相位移动并叠加，可以得到电压在V/Vpi大小下的传输曲线。
其中V为总电压大小，Vpi)为半波电压大小，phi代表黄金分割的数值:0.618(取3位有效数字)，这几个字符表达的含义将在下面的实施例中继续沿用。
根据图7对应的调制器获取光场传输曲线，请参阅图8，图8是本发明实施例中光场传输曲线一个对比示意图，图8上方的图示为级联下的马赫-曾德尔器件调制曲线，且图中1号曲线为传统调制器调制得到的曲线，2号曲线为本发明方案中的调制器调制后得到的曲线。2号曲线实际上为两个MZM器件输出的调制曲线进行叠加后形成的，且这两个MZM器件在设计时需要保持设计结构一致，但是输出的电压不同。连接正向电压的MZM器件的Vpi应是连接负向电压的MZM器件的Vpi两倍，因此，两者的传输曲线周期也是两倍的关系，即第一传输曲线周期为第二传输曲线周期的两倍，合成采用定向耦合器引入90°相移，且从图8中可以看出，当γ接近0.18时传输曲线更趋于直线，γ为特定光场强度比。图8下方为光场传输曲线的绝对值函数，图中1号曲线为传统调制器调制得到的曲线，2号曲线为本发明方案中的调制器调制后得到的曲线，通过光场传输曲线的绝对值函数也可以得到同样的结论，即为2号曲线更加接近直线，由此进一步支持通过上述方法调制后得到的传输曲线更为优质。
本发明方案中提供的一种调制器结构，采用MZM器件级联的方法，通过级联两个Vpi成倍数关系的MZM并以特定光场强比(1：0.18)合成传输曲线叠加，使得传输曲线变成线性传输函数。
其次，本发明实施例中，在调制器中引入了非对称耦合模块，该非对称耦合模块可以是定向耦合器，也可以是MMI，非对称耦合模块主要用于加入相移，使得在合成传输曲线之前，对预先得到的第一传输曲线进行相位上的调整，可以更快更准确的与第二传输曲线进行相位上的结合，避免因为相位上的差异 导致合成的传输曲线无法达到预期效果。使用非对称耦合模块可以提升方案的实用性以及可行性，且非对称耦合模块中的定向耦合器与多模干涉仪的功能类似，在实际应用中可以根据需要选择合适的仪器，增加方案的多样性。
可选地，在上述图5对应的实施例的基础上，本发明实施例提供的调制器的第二个可选实施例中，请参阅图9，图9是本发明实施例中实现高阶调制的调制器另一个实施例示意图，所述调制器100还包括第一相移模块105以及第一衰减模块106；
所述第一相移模块105，用于对所述第一传输曲线与所述第二传输曲线进行相位的调整，并得到调整后的第一传输曲线与调整后的第二传输曲线，以使所述合成模块将所述调整后的第一传输曲线与所述调整后的第二传输曲线进行相位上的叠加，以得到合成后的线性结果；
所述第一衰减模块106，用于控制所述调整后的第一传输曲线与所述调整后的第二传输曲线的曲线比例大小，以根据所述曲线比例大小对所述线性结果进行预补偿，并输出预补偿后的线性结果。
本实施例中，在合成模块对第一传输曲线与第二传输曲线进行叠加之前，可以引入第一相移模块，其主要功能使对第一传输曲线与第二传输曲线进行相位上的调整，调整的方法是，对第一传输曲线进行相位上的偏移，或者对第二传输曲线进行相位上的偏移，还可以同时对两者都进行相位上的偏移，具体偏移角度根据实际情况进行设定，此处不做限定。合成模块对调整后的第一传输曲线与第二传输曲线进行相位上的叠加，得到所需的线性结果，线性结果即为传输曲线中最趋近于线性的部分。同样地，合成模块也可以对第一传输曲线与调整后的第二传输曲线进行相位上的叠加，或者对调整后的第一传输曲线与调整后的第二传输曲线进行相位上的叠加。具体情况根据实际需求适当调整。
而在该调制中还可以引入第一衰减模块，该第一衰减模块用于控制调制后的第一传输曲线与调整后的第二传输曲线的曲线比例大小，加入第一衰减模块后可以调节曲线形状，根据上述通过第一相移模块得到的线性结果进行预补偿，可以得到更趋于直线的线性结果。
除非是系统信道中光功率刻意的保持很低，否则非线性损伤会影响所有长距离光传输系统，采用预补偿的方法可以得到更加接近线性的结果。对于有很 高高峰平均功率比(英文全称：Peak to Average Power Ratio，英文缩写：PAPR)的相干光正交频分复用(英文全称：Coherent-Orthogonal Frequency Division Multiplexing，英文缩写：CO-OFDM)技术系统更是如此。由于光正交频分复用技术(英文全称：Orthogonal Frequency Division Multiplexing，英文缩写：OFDM)信号是由一系列的子信道信号重叠起来的，所以很容易使时域信号具有高的PAPR。与无线通信系统相比，光纤通信系统属于非线性媒质传输，由于光OFDM系统各子载波之间频谱间隔小，这使得子载波间的走离效应很弱，很容易满足非线性四波混频(英文全称：four-wave mixing，英文缩写：FWM)相互作用产生的条件，形成串扰。
在OFDM系统当中，由于高的PAPR会产生严重的非线性损伤，所以可以从降低PAPR的方面入手来减弱非线性损伤的影响。一些方法已经被研究用于降低OFDM系统的PAPR。例如限幅技术、预编码、部分传输技术、选择性映射、光学相位调制器。限幅技术是最简单也是在实时处理系统中广泛采用的技术，但是它会引入限幅噪声从而影响系统的性能。其它方法增加了额外的复杂度、编码开销、额外增加光学器件等。
具体地，请参阅图10，图10是本发明实施例中调制器的另一个结构示意图，图中在合成模块合成调制曲线前，还可以引入相移器和衰减器，相移器用于大幅度的调制第一传输曲线与第二传输曲线的相位，而衰减器则是小幅度的对合成后的传输曲线进行预补偿。首先开启激光器，数据分别通过正极和负极输入到调制器，正极传导的是正向电压，正向电压大小为V/(2*Vpi)，得到传统马赫-曾德尔高低电压调制曲线，即为第一传输曲线，负极传导的是负向电压，负向电压大小为V/Vpi，也得到传统马赫-曾德尔高低电压调制曲线，即为第二传输曲线，两条传输曲线先经过MZM器件，再由相移器对两条曲线进行相位的移动，使得叠加的初始相位一致，正向电压对应的相移为cos(phi)，负向电压对应的相移为-sin(2*phi)/2，，通过第一传输曲线与第二传输曲线进行相位移动并叠加，可以得到电压在V/Vpi大小下的传输曲线，然而该传输曲线还可以更加趋于直线，此时，需要衰减器对得到的传输曲线进行预补偿，通过控制两路光场的比例来得到线性结果。
根据图10对应的调制器获取光场传输曲线，请参阅图11，图11是本发 明实施例中光场传输曲线另一个对比示意图，图11上方的图示为级联下的马赫-曾德尔器件调制曲线，且图中1号曲线为传统调制器调制得到的曲线，2号曲线为本发明方案中的调制器调制后得到的曲线。2号曲线实际上为两个MZM器件输出的调制曲线进行叠加后形成的，且这两个MZM器件在设计时需要保持设计结构一致，但是输出的电压不同。连接正向电压的MZM器件的Vpi应是连接负向电压的MZM器件的Vpi两倍，因此，两者的传输曲线周期也是两倍的关系，即第一传输曲线周期为第二传输曲线周期的两倍，合成采用相移器进行相位控制，衰减器控制两路光场的比例，且从图11可以看出，当γ接近0.4时传输曲线可以对接收到的信号做预补偿处理，使得传输曲线更趋于直线，γ为特定光场强比。图11下方为光场传输曲线的绝对值函数，图中1号曲线为传统调制器调制得到的曲线，2号曲线为本发明方案中的调制器调制后得到的曲线，通过光场传输曲线的绝对值函数也可以得到同样的结论，即为2号曲线的线性效果更加明显。
本发明方案中提供的一种调制器结构，采用MZM器件级联的方法，通过级联两个Vpi成倍数关系的MZM并以特定光场强比(1：0.4)合成传输曲线叠加，使得传输曲线对非线性器件进行预补偿。
再次，本发明实施例中，在调制器中引入了相移器和衰减器，实现对调制器调制的传输曲线进行调节，增加其灵活性，相比只针对第一传输曲线做相位上的调整而言，可以对两条或两条以上的传输曲线都进行调节，达到更好的合成效果。在调制器中增加衰减器可以实现对外围电器件的预补偿，适用于多电平调制的场景和高阶调制的场景，增强方案的实用性和可行性。
可选地，在上述图5对应的实施例的基础上，本发明实施例提供的调制器的第三个可选实施例中，所述调制器还包括第三调制模块、第二相移模块以及第二衰减模块；
所述第三调制模块，用于接收第三待调制数据，并根据所述第三待调制数据输出第三传输曲线，其中，所述第三传输曲线的周期为所述第二传输曲线的周期的二分之一；
所述第二相移模块，用于对所述第一传输曲线、所述第二传输曲线以及所述第三传输曲线进行相位的调整，并得到所述调整后的第一传输曲线、所述调 整后的第二传输曲线以及调整后的第三传输曲线，以使所述合成模块将所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线进行相位上的叠加，以得到合成后的线性结果；
所述第二衰减模块，用于控制所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线的曲线比例大小，以根据所述曲线比例大小对所述线性结果进行预补偿，并输出预补偿后的线性结果。
本实施例中，将应用于调制器中有多条周期存在倍数关系的曲线进行叠加的情况。请参阅图12，图12是本发明实施例中调制器的另一个结构示意图，图中以三个MZM器件为例进行描述，在实际应用中，并不仅限于三个MZM器件级联构成的调制器。首先开启激光器，数据分别输入至三个接收模块，第一调制模块接收第一待调制数据，并根据第一待调制数据输出第一传输曲线，第二调制模块接收第二待调制数据，并根据第二待调制数据输出第二传输曲线，第二传输曲线的周期为第一传输曲线的周期的二分之一，新增的第三调制模块接收第三调制数据，并根据第三待调制数据输出第三传输曲线，其中，第三传输曲线的周期为第二传输曲线的周期的二分之一。
得到第一传输曲线、第二传输曲线以及第三传输曲线后，第二相移模块将这三者进行相位上的调整，可以理解的是，第二相移模块与第一相移模块的设计结构基本保持一致，不需要重新进行设计。经过第二相移模块的相位调整后，可以得到调整后的第一传输曲线、调整后的第二传输曲线以及调整后的第三传输曲线，这三条传输曲线在初始相位上是一样的，以使得合成模块可以将三条传输曲线进行相位上的叠加，以得到合成后的线性结果。
需要说明的是，第一传输曲线在电压为V/(4*Vpi)的条件下获取，得到调制曲线表达式为
Figure PCTCN2015094119-appb-000003
对应的相移为cos(phi)。第二传输曲线在电压为V/(2*Vpi)的条件下获取，得到调制曲线表达式为
Figure PCTCN2015094119-appb-000004
对应的相移为-sin(2*phi)/2。第三传输曲线在电压为V/(Vpi)的条件下获取，得到调制曲线表达式为
Figure PCTCN2015094119-appb-000005
对应的相移为-sin(4*phi)/2。
合成模块可以将三条传输曲线进行相位上的叠加，得到合成后的线性结果之后，通过第二衰减模块控制所述调整后的第一传输曲线、调整后的第二传输曲线以及调整后的第三传输曲线的曲线比例大小，以根据曲线比例大小对前期 得到的线性结果进行预补偿，并输出预补偿后的线性结果。补偿后的线性结果将更加趋于线性化。
本发明方案中提供的一种调制器结构，采用MZM器件级联的方法，通过级联三个Vpi成倍数关系的MZM并以特定光场强比(1：0.12)合成传输曲线叠加，使得传输曲线变成线性传输函数。
其次，本发明实施例中，提供了一种可以将多条传输曲线进行叠加合成的调制器，且多条传输曲线的周期应呈倍数关系。利用多条传输曲线通过第二相移模块的相位调整，以及第二衰减模块对合成后的传输曲线进行预补偿，得到调制器输出的调制曲线更加趋于线性化，同时，多条传输曲线进行叠加后得到的线性结果也更加精细化。
可选地，在上述图9对应的实施例的基础上，本发明实施例提供的调制器的第二个可选实施例中，所述第一调制模块与所述第一相移模块相连，所述第一相移模块通过所述第二调制模块与所述第一衰减模块相连。
本实施例中，将应用于调制器中有多条周期存在倍数关系的曲线进行叠加的情况，并且将调制器内多个MZM器件从并行相连的方法变化为串行相连，在结构上做了变型。请参阅图13，图13是本发明实施例中调制器的另一个结构示意图，图中以两个MZM器件为例进行描述，在实际应用中，并不仅限于三个MZM器件级联构成的调制器。首先开启激光器，数据分别输入至两个接收模块，第一调制模块接收第一待调制数据，并根据第一待调制数据输出第一传输曲线，第二调制模块接收第二待调制数据，并根据第二待调制数据输出第二传输曲线，第二传输曲线的周期为第一传输曲线的周期的二分之一。
由于调制器结构进行了变型，因此第一调制模块与第一相移模块相连，第一相移模块可以直接对第一调制模块输出的第一传输曲线进行相位上的移动，而从负极电压输入的数据先通过第一衰减模块，对接收到的数据做预补偿处理，然后将补偿后得到的第二待调制数据输入至第二调制模块，第二调制模块根据补偿后得到的第二待调制数据输出第二传输曲线，最后，将相移后的第一传输曲线与第二传输曲线进行叠加，合成调制后的传输曲线。
然而，在使用串行级联的方式设计调制器，需要对控制点进行优化，具体地，控制点也可以认为接收信号的部分，若要得到更为精确化的数据，需要对 接收到的信号进行放大，以达到最佳的使用效果。
再次，本发明实施例中，提供了一种调制器结构，可以将多条传输曲线进行叠加合成，通过第一相移模块对第一传输曲线进行相位调整。通过第一衰减模块对第二传输曲线进行预补偿，以得到更趋于线性化的曲线，同时，本发明方案将并行级联变化为串行级联，形成另一种传输曲线可调的调制器结构，使得调制器结构更加多元化，便于设计和应用，提升方案的可行性。
本发明实施例中，还提供了一种实现高阶调制的系统，该系统中包括两个或两个以上的调制器，该调制器为图5对应的实施例、图5对应的第一个可选实施例、图9对应的实施例、图9对应的第一个可选实施例和图9对应的第二个可选实施例中任意一项所述调制器。
本实施例中，将进一步优化调制器的结构，即为将多个调制器通过级联的方式得到一个用于实现高阶调制的系统，可以直接对数据进行分段式的优化，也就是说，每个调制器分别对数据进行优化，以得到更趋于线性的的调制曲线。
请参阅图14，图14是本发明实施例中双偏振正交相移键控/正交振幅调制的一个调制结构，首先开启激光器，光通过偏振分束器后可以将两路不同振动方向的光分开。实现高阶调制的系统包括多个调制器，这些调制器是指叠加的同相正交(英文全称：in-phase quadrature，英文缩写：IQ)调制器架构，IQ调制就是数据分为两路，分别进行载波调制，两路载波相互正交。IQ调制是矢量的方向问题，同相就是矢量方向相同的信号，正交分量就是两个信号矢量正交(相差90°)；IQ信号一路是0°和180°，另一路是90°和270°，分别叫做I路和Q路，它们就是两路正交的信号。
每个IQ调制器架构都是由两个或两个以上的调制器叠加而成的，IQ调制器架构接收到数据后，同样以上述实施例中提及的调制器输出趋于线性化的传输曲线相似，即，接收两条或两条以上的传输曲线，通过对相位的移动，以及对光场比例的控制，合成一条调制后的传输曲线，且该曲线更趋于线性化。
IQ调制器架构分别将经过调制后的传输曲线以X轴和Y轴的方向输出至合束偏振器，通过合束偏振器将X轴和Y轴的传输曲线合成，并得到调制后的信号。
本发明实施例中，提供了一种由多个调制器组合构成的调制系统，可以进 一步优化调制器的结构，直接将信号进行分段处理，通过调制器叠加而成的IQ调制器架构来实现各种码型的调制，以此增强方案的灵活性，并可用于实现更高阶码型的调制。与此同时，本发明实施例减小了对数字信号处理的依赖，直接在光路上做部分信号的处理，改善信号质量。
本发明实施例提供了一种实现高阶调制的方法，其中，为了描述方便，将以调制器的角度进行描述，请参考图15，图15为本发明实施例提供的一种实现高阶调制的方法的流程示意图，其中，所述实现高阶调制的方法方法可包括：
201、接收第一待调制数据，并根据第一待调制数据输出第一传输曲线；
本实施例中，用于实现高阶调制的调制器在正极电压的控制下，接收第一待调制数据，并将第一待调制数据进行输出，得到对应的第一传输曲线，且第一传输曲线呈正弦型。
202、接收第二待调制数据，并根据第二待调制数据输出第二传输曲线，其中，第二传输曲线的周期为第一传输曲线的周期的二分之一；
本实施例中，用于实现高阶调制的调制器在负极电压的控制下，接收第二待调制数据，并输出第二待调制数据，得到对应的第二传输曲线，同样地，该第二传输曲线也是呈正弦型。然而由于正极电压与负极电压之间具有电压差，负极电压是正极电压的一半，因此所得到的第二传输曲线的周期为第一传输曲线的周期的二分之一。
203、将第一传输曲线与第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
本实施例中，调制器将第一传输曲线与第二传输曲线进行相位上的叠加，进而合成线性结果。其合成两条曲线的具体做法与上述图3对应的实施例中介绍的方案类似，故此处不再赘述。
本发明实施例中，提供了一种实现高阶调制的方法，制器对接收到的第一待调制数据以及第二待调制数据进行调制，并输出对应的第一传输曲线和第二传输曲线，其中，第二传输曲线与第一传输曲线呈倍数关系，将两条传输曲线进行相位上的叠加，得到需要的线性结果。调制器可以通过控制传输曲线之间的叠加比例得到可调制的线性结果，从而实现线性曲线的传输，适用于多种调 制场景，增强方案的灵活性。
可选地，在上述图15对应的实施例的基础上，本发明实施例提供的实现高阶调制的方法第一个可选实施例中，将第一传输曲线与第二传输曲线进行相位上的叠加之前，还可以包括：
为第一传输曲线增加预置相移值，得到偏移后的第一传输曲线；
将所述第一传输曲线与第二传输曲线进行相位上的叠加，以得到合成后的线性结果，可以包括：
将偏移后的第一传输曲线与第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
本实施例中，在调制器对第一传输曲线与第二传输曲线进行叠加之前，需要对第一传输曲线进行相位上的偏移，偏移量可以为90°，也可以是根据实际情况设定的其他预置相移值，并不仅限于90°。在得到偏移后的第一传输曲线后，可以将偏移后的第一传输曲线与第二传输曲线进行相位上的叠加，从而合成调制后的传输曲线。
其次，本发明实施例中，提供了一种在调制器中加入相移的方法，使得在合成传输曲线之前，对预先得到的第一传输曲线进行相位上的调整，可以更快更准确的与第二传输曲线进行相位上的结合，避免因为相位上的差异导致合成的传输曲线无法达到预期效果，从而提升方案的实用性以及可行性，且在实际应用中可以根据需要选择合适的仪器，增加方案的多样性。
可选地，在上述图15对应的实施例的基础上，本发明实施例提供的实现高阶调制的方法第二个可选实施例中，将第一传输曲线与第二传输曲线进行相位上的叠加之前，还可以包括：
对第一传输曲线与第二传输曲线进行相位的调整，并得到调整后的第一传输曲线与调整后的第二传输曲线，以使调整后的第一传输曲线与调整后的第二传输曲线进行相位上的叠加；
控制调整后的第一传输曲线与调整后的第二传输曲线的曲线比例大小，以根据曲线比例大小对线性结果进行预补偿，并输出预补偿后的线性结果。
本实施例中，对第一传输曲线与第二传输曲线进行叠加之前，可以对第一传输曲线与第二传输曲线进行相位上的调整，调整的方法是，对第一传输曲线 进行相位上的偏移，或者对第二传输曲线进行相位上的偏移，还可以同时对两者都进行相位上的偏移，具体偏移角度根据实际情况进行设定，此处不做限定。调制器对调整后的第一传输曲线与第二传输曲线进行相位上的叠加，得到所需的线性结果，线性结果即为传输曲线中最趋近于线性的部分。同样地，也可以对第一传输曲线与调整后的第二传输曲线进行相位上的叠加，或者对调整后的第一传输曲线与调整后的第二传输曲线进行相位上的叠加。具体情况根据实际需求适当调整。
在上述情况下，还可以控制调制后的第一传输曲线与调整后的第二传输曲线的曲线比例大小，调节曲线形状，根据上述通过得到的线性结果进行预补偿，可以得到更趋于直线的线性结果。
除非是系统信道中光功率刻意的保持很低，否则非线性损伤会影响所有长距离光传输系统，采用预补偿的方法可以得到更加接近线性的结果。对于有很高PAPR的CO-OFDM技术系统更是如此。由于光OFDM信号是由一系列的子信道信号重叠起来的，所以很容易使时域信号具有高的PAPR。与无线通信系统相比，光纤通信系统属于非线性媒质传输，由于光OFDM系统各子载波之间频谱间隔小，这使得子载波间的走离效应很弱，很容易满足非线性FWM相互作用产生的条件，形成串扰。
在OFDM系统当中，由于高的PAPR会产生严重的非线性损伤，所以可以从降低PAPR的方面入手来减弱非线性损伤的影响。一些方法已经被研究用于降低OFDM系统的PAPR。例如限幅技术、预编码、部分传输技术、选择性映射、光学相位调制器。限幅技术是最简单也是在实时处理系统中广泛采用的技术，但是它会引入限幅噪声从而影响系统的性能。其它方法增加了额外的复杂度、编码开销、额外增加光学器件等。
再次，本发明实施例中，提供了一种实现对调制器调制的传输曲线进行调节的方法，以此增加其灵活性，相比只针对第一传输曲线做相位上的调整而言，可以对两条或两条以上的传输曲线都进行调节，达到更好的合成效果。在调制器中增加衰减器可以实现对外围电器件的预补偿，适用于多电平调制的场景和高阶调制的场景，增强方案的实用性和可行性。
可选地，在上述图15对应的实施例的基础上，本发明实施例提供的实现 高阶调制的方法第三个可选实施例中，接收第二待调制数据，并根据第二待调制数据输出第二传输曲线之后，还可以包括：
接收第三待调制数据，并根据第三待调制数据输出第三传输曲线，其中，第三传输曲线的周期为第二传输曲线的周期的二分之一；
对第一传输曲线、第二传输曲线以及第三传输曲线进行相位的调整，并得到调整后的第一传输曲线、调整后的第二传输曲线以及调整后的第三传输曲线，以将调整后的第一传输曲线、调整后的第二传输曲线以及调整后的第三传输曲线进行相位上的叠加；
控制调整后的第一传输曲线、调整后的第二传输曲线以及调整后的第三传输曲线的曲线比例大小，以根据曲线比例大小对线性结果进行预补偿，并输出预补偿后的线性结果。
本实施例中，首先开启激光器，数据分别输入调制器，接收第一待调制数据，并根据第一待调制数据输出第一传输曲线，接收第二待调制数据，并根据第二待调制数据输出第二传输曲线，第二传输曲线的周期为第一传输曲线的周期的二分之一，接收第三调制数据，并根据第三待调制数据输出第三传输曲线，其中，第三传输曲线的周期为第二传输曲线的周期的二分之一。
得到第一传输曲线、第二传输曲线以及第三传输曲线后，将这三者进行相位上的调整。经过相位调整后，可以得到调整后的第一传输曲线、调整后的第二传输曲线以及调整后的第三传输曲线，这三条传输曲线在初始相位上是一样的，可以将三条传输曲线进行相位上的叠加，以得到合成后的线性结果。
通过控制调整后的第一传输曲线、调整后的第二传输曲线以及调整后的第三传输曲线的曲线比例大小，以根据曲线比例大小对前期得到的线性结果进行预补偿，并输出预补偿后的线性结果。补偿后的线性结果将更加趋于线性化。
其次，本发明实施例中，提供了一种可以将多条传输曲线进行叠加合成的方法，且多条传输曲线的周期应呈倍数关系。利用多条传输曲线通过相位调整，以及对合成后的传输曲线进行预补偿，得到调制器输出的调制曲线更加趋于线性化，同时，多条传输曲线进行叠加后得到的线性结果也更加精细化。
可选地，在上述图15对应的第二个实施例的基础上，本发明实施例提供的实现高阶调制的方法第四个可选实施例中，接收第一待调制数据，并根据第 一待调制数据输出第一传输曲线之后，还可以包括：
对第一传输曲线进行相位的调整；
接收第二待调制数据，并根据第二待调制数据输出第二传输曲线之后，还可以包括：
控制调整后的第一传输曲线与第二传输曲线的曲线比例大小。
本实施例中，将应用于调制器中有多条周期存在倍数关系的曲线进行叠加，并且将调制器内多个MZM器件从并行相连的方法变化为串行相连，在结构上做了变型。
具体地，首先开启激光器，数据分别输入调制器，调制器接收第一待调制数据，并根据第一待调制数据输出第一传输曲线，同时，接收第二待调制数据，并根据第二待调制数据输出第二传输曲线，第二传输曲线的周期为第一传输曲线的周期的二分之一。
由于调制器结构进行了变型，因此可以直接对输出的第一传输曲线进行相位上的移动，而对负极电压输入的数据做预补偿处理，然后将补偿后得到的第二待调制数据进行输出，得到第二传输曲线，最后，将相移后的第一传输曲线与第二传输曲线进行叠加，合成调制后的传输曲线。
然而，在使用串行级联的方式设计调制器，需要对控制点进行优化，具体地，控制点也可以认为接收信号的部分，若要得到更为精确化的数据，需要对接收到的信号进行放大，以达到最佳的使用效果。
再次，本发明实施例中，提供了一种实现调制的方法，可以将多条传输曲线进行叠加合成，对第一传输曲线进行相位调整。同时也对第二传输曲线进行预补偿，以得到更趋于线性化的曲线，本发明方案将并行级联变化为串行级联，形成另一种传输曲线可调的调制器结构，使得调制器结构更加多元化，便于设计和应用，提升方案的可行性。
在上述实施例中，对各个实施例的描述都各有侧重，某个实施例中没有详述的部分，可以参见其他实施例的相关描述。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统，装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另 外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本发明各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。
所述集成的单元如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本发明的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的全部或部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本发明各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(英文全称：Read-Only Memory，英文缩写：ROM)、随机存取存储器(英文全称：Random Access Memory，英文缩写：RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
以上对本发明所提供的一种调制器、调制系统以及实现高阶调制的方法进行了详细介绍，本文中应用了具体个例对本发明的原理及实施方式进行了阐述，以上实施例的说明只是用于帮助理解本发明的方法及其核心思想；同时，对于本领域的技术人员，依据本发明实施例的思想，在具体实施方式及应用范围上均会有改变之处，综上所述，本说明书内容不应理解为对本发明的限制。

Claims (11)

  1. 一种调制器，其特征在于，包括：
    第一调制模块，用于接收第一待调制数据，并根据所述第一待调制数据输出第一传输曲线；
    第二调制模块，用于接收第二待调制数据，并根据所述第二待调制数据输出第二传输曲线，其中，所述第二传输曲线的周期为所述第一传输曲线的周期的二分之一；
    合成模块，用于将所述第一传输曲线与所述第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
  2. 根据权利要求1所述的调制器，其特征在于，所述调制器还包括非对称耦合模块；
    所述非对称耦合模块，用于为所述第一传输曲线增加预置相移值，得到偏移后的第一传输曲线；
    所述合成模块，还用于将所述偏移后的第一传输曲线与所述第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
  3. 根据权利要求1所述的调制器，其特征在于，所述调制器还包括第一相移模块以及第一衰减模块；
    所述第一相移模块，用于对所述第一传输曲线与所述第二传输曲线进行相位的调整，并得到调整后的第一传输曲线与调整后的第二传输曲线，以使所述合成模块将所述调整后的第一传输曲线与所述调整后的第二传输曲线进行相位上的叠加，以得到合成后的线性结果；
    所述第一衰减模块，用于控制所述调整后的第一传输曲线与所述调整后的第二传输曲线的曲线比例大小，以根据所述曲线比例大小对所述线性结果进行预补偿，并输出预补偿后的线性结果。
  4. 根据权利要求1所述的调制器，其特征在于，所述调制器还包括第三调制模块、第二相移模块以及第二衰减模块；
    所述第三调制模块，用于接收第三待调制数据，并根据所述第三待调制数据输出第三传输曲线，其中，所述第三传输曲线的周期为所述第二传输曲线的周期的二分之一；
    所述第二相移模块，用于对所述第一传输曲线、所述第二传输曲线以及所述第三传输曲线进行相位的调整，并得到所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线，以使所述合成模块将所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线进行相位上的叠加，以得到合成后的线性结果；
    所述第二衰减模块，用于控制所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线的曲线比例大小，以根据所述曲线比例大小对所述线性结果进行预补偿，并输出预补偿后的线性结果。
  5. 根据权利要求3所述的调制器，其特征在于，
    所述第一调制模块与所述第一相移模块相连，所述第一相移模块通过所述第二调制模块与所述第一衰减模块相连。
  6. 一种实现高阶调制的系统，其特征在于，所述系统包括至少一个调制器；
    所述调制器如权利要求1至5中任意一项所述的调制器。
  7. 一种实现高阶调制的方法，其特征在于，包括：
    接收第一待调制数据，并根据所述第一待调制数据输出第一传输曲线；
    接收第二待调制数据，并根据所述第二待调制数据输出第二传输曲线，其中，所述第二传输曲线的周期为所述第一传输曲线的周期的二分之一；
    将所述第一传输曲线与所述第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
  8. 根据权利要求7所述的方法，其特征在于，所述将所述第一传输曲线与所述第二传输曲线进行相位上的叠加之前，所述方法还包括：
    为所述第一传输曲线增加预置相移值，得到偏移后的第一传输曲线；
    所述将所述第一传输曲线与所述第二传输曲线进行相位上的叠加，以得到合成后的线性结果，包括：
    将所述偏移后的第一传输曲线与所述第二传输曲线进行相位上的叠加，以得到合成后的线性结果。
  9. 根据权利要求7所述的方法，其特征在于，所述将所述第一传输曲线与所述第二传输曲线进行相位上的叠加之前，所述方法还包括：
    对所述第一传输曲线与所述第二传输曲线进行相位的调整，并得到调整后的第一传输曲线与调整后的第二传输曲线，以使所述调整后的第一传输曲线与所述调整后的第二传输曲线进行相位上的叠加；
    控制所述调整后的第一传输曲线与所述调整后的第二传输曲线的曲线比例大小，以根据所述曲线比例大小对所述线性结果进行预补偿，并输出预补偿后的线性结果。
  10. 根据权利要求7所述的方法，其特征在于，所述接收第二待调制数据，并根据所述第二待调制数据输出第二传输曲线之后，所述方法还包括：
    接收第三待调制数据，并根据所述第三待调制数据输出第三传输曲线，其中，所述第三传输曲线的周期为所述第二传输曲线的周期的二分之一；
    对所述第一传输曲线、所述第二传输曲线以及所述第三传输曲线进行相位的调整，并得到所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线，以将所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线进行相位上的叠加；
    控制所述调整后的第一传输曲线、所述调整后的第二传输曲线以及调整后的第三传输曲线的曲线比例大小，以根据所述曲线比例大小对所述线性结果进行预补偿，并输出预补偿后的线性结果。
  11. 根据权利要求9所述的方法，其特征在于，所述接收第一待调制数据，并根据所述第一待调制数据输出第一传输曲线之后，所述方法还包括：
    对所述第一传输曲线进行相位的调整；
    所述接收第二待调制数据，并根据所述第二待调制数据输出第二传输曲线之后，所述方法还包括：
    控制所述调整后的第一传输曲线与所述第二传输曲线的曲线比例大小。
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