WO2010045802A1 - 一种光解偏振复用光载波的方法、装置和系统 - Google Patents

一种光解偏振复用光载波的方法、装置和系统 Download PDF

Info

Publication number
WO2010045802A1
WO2010045802A1 PCT/CN2009/072405 CN2009072405W WO2010045802A1 WO 2010045802 A1 WO2010045802 A1 WO 2010045802A1 CN 2009072405 W CN2009072405 W CN 2009072405W WO 2010045802 A1 WO2010045802 A1 WO 2010045802A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical
signal
polarization
carrier
signals
Prior art date
Application number
PCT/CN2009/072405
Other languages
English (en)
French (fr)
Inventor
熊前进
李良川
黄远达
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to EP09821523A priority Critical patent/EP2352239A4/en
Priority to BRPI0919797A priority patent/BRPI0919797A2/pt
Publication of WO2010045802A1 publication Critical patent/WO2010045802A1/zh
Priority to US13/091,843 priority patent/US20110206375A1/en

Links

Classifications

    • 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
    • H04B10/60—Receivers
    • H04B10/66—Non-coherent receivers, e.g. using direct detection
    • H04B10/67—Optical arrangements in the receiver
    • H04B10/671—Optical arrangements in the receiver for controlling the input optical signal
    • 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
    • H04B10/516—Details of coding or modulation
    • H04B10/5165—Carrier suppressed; Single sideband; Double sideband or vestigial
    • 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
    • H04B10/60—Receivers
    • H04B10/66—Non-coherent receivers, e.g. using direct detection
    • H04B10/67—Optical arrangements in the receiver
    • H04B10/676—Optical arrangements in the receiver for all-optical demodulation of the input optical signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/06—Polarisation multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2210/00—Indexing scheme relating to optical transmission systems
    • H04B2210/003—Devices including multiple stages, e.g., multi-stage optical amplifiers or dispersion compensators

Definitions

  • the present invention claims a method and a device for applying a photodegradation polarization multiplexed optical carrier, which is filed on October 22, 2008, with the application number of 200810167346.5.
  • the present invention relates to the field of optical communication technologies, and in particular, to a method, apparatus and system for optically depolarizing a multiplexed optical carrier. Background technique
  • the single channel rate is increasing, and has reached or exceeded 40 Gbps.
  • the increase of the rate will inevitably affect the spectrum utilization of the system, optoelectronic devices and Chromatic Dispersion (CD), polarization mode dispersion ( Polarization Mode Dispersion, PMD) has higher tolerances.
  • CD Chromatic Dispersion
  • PMD Polarization Mode Dispersion
  • a polarization multiplexed modulated signal of an optical carrier is photo-demultiplexed and multiplexed by a polarization splitter 101 (PBS) at the receiving end to obtain signals x1 and x2.
  • PBS polarization splitter 101
  • the minimum mean square error estimation MSE algorithm 105 is used, and the inverse matrix of the channel is estimated by the demultiplexer DMUX102.
  • the channel inverse matrix estimation is controlled by the mean square error al and a2 of the demodulated signal, and the demultiplexer DMUX102 outputs the signal yl.
  • y2; yl and y2 are respectively converted into electrical signals si, s2 by photodiodes (103A, 103B), and then demodulated and output by the receiver RX (104A, 104B), and the signal demodulation function is realized by the receiver RX.
  • the prior art adopts polarization multiplexing of an optical carrier to improve the spectrum utilization of the system, converts the polarization multiplexed modulated signal into an electrical signal, and then performs demodulation, and controls the mean square error of the demodulated signal as a feedback signal.
  • the various parameters of the DMUX demultiplexer are very demanding for analog-to-digital converters (ADCs) and other devices; and because single-carrier polarization multiplexing is a two-way transmission signal, the rate of each signal It will still be very high, even though the pattern and filter adjustment can improve the spectrum utilization to a certain extent, but the improvement is very limited, and it is easy to bring Signal damage. Summary of the invention
  • embodiments of the present invention provide a method, apparatus, and system for optically depolarizing a multiplexed optical carrier, which can improve spectrum utilization of the system, improve chromatic dispersion CD and polarization mode dispersion PMD tolerance, and reduce the pair. Device requirements and complexity at the receiving end.
  • a method for optically depolarizing a multiplexed optical carrier including:
  • a partial signal is extracted from each of the to-be-demodulated optical signals to calculate a characteristic characterizing the polarization state, and the feedback signal is controlled according to the feature, and the polarization state of each of the photonic carriers is correspondingly adjusted.
  • an apparatus for optically depolarizing a multiplexed optical carrier including:
  • a photon carrier separator configured to separate the optical carrier into two or more optical carriers at the receiving end; and a polarization beam splitter PBS for respectively optically demultiplexing each optical subcarrier separated by the optical subcarrier separator Two way to demodulate the optical signal;
  • a feedback processing module configured to extract a partial signal from each of the to-be-demodulated optical signals multiplexed by the polarization splitter PBS, and calculate a characteristic of the polarization state, and control the feedback signal input to the polarization control according to the feature Module PC;
  • the polarization control module PC is configured to adjust an incident angle of each of the photo subcarriers according to a feedback signal input by the feedback processing module.
  • a system for optically depolarizing a multiplexed optical carrier including:
  • the transmitting end device is configured to separate the optical carrier into two or more photo subcarrier signals at the transmitting end, respectively modulate two polarization multiplexing modulated signals for each photo subcarrier signal, and respectively combine the polarization multiplexing modulated signals After combining, the signal is still output on the optical carrier;
  • the receiving end device is configured to separate the optical carrier into two or more photo subcarrier signals at the receiving end, and separately demultiplex the optical signals to be demodulated and optically demodulated for each optical subcarrier signal, and to demodulate the light to be demodulated from each channel.
  • the partial signal is extracted from the signal to calculate a characteristic characterizing the polarization state, and the polarization state of each of the photonic carriers is correspondingly adjusted according to the characteristic control feedback signal.
  • each of the optical subcarriers is optically demultiplexed and multiplexed with two optical signals to be demodulated, and each optical signal to be demodulated is used.
  • the line rate is reduced to less than 1/4 of the original, which can improve the spectrum utilization of the system, improve the chromatic dispersion CD and the polarization mode dispersion PMD tolerance, and complete the photodepolarization in the form of light waves without complicated calculations. Use, to reduce the requirements and complexity of the receiving device.
  • FIG. 1 is a structural diagram of a prior art photo-decoding polarization multiplexing receiving end device
  • FIG. 2 is a structural diagram of a device for optically depolarizing multiplexed optical carrier according to an embodiment of the present invention
  • FIG. 3 is a structural diagram of a photonic carrier separator according to an embodiment of the present invention
  • FIG. 4 is a structural diagram of an apparatus for optimizing an optically depolarized multiplexed optical carrier according to an embodiment of the present invention
  • FIG. 5 is a flowchart of a method for optically depolarizing a multiplexed optical carrier according to an embodiment of the present invention
  • FIG. 7 is a schematic diagram of a system for optically depolarizing a multiplexed optical carrier according to an embodiment of the present invention. detailed description
  • FIG. 2 is an apparatus for optically depolarizing a multiplexed optical carrier according to an embodiment of the present invention, including: a photo subcarrier separator 210, configured to separate an optical carrier into two or more photo subcarriers at a receiving end;
  • the PBS (220A, 220B) is configured to photo-depolarize and multiplex two optical signals to be demodulated for each optical subcarrier separated by the optical subcarrier separator 210;
  • a feedback processing module (230A, 230B) for extracting a partial signal from each of the to-be-demodulated optical signals multiplexed by the polarization splitter PBS, and calculating a characteristic of the polarization state, and controlling the feedback according to the feature
  • the signal is input to the polarization control module PC;
  • the polarization control module PC (240A, 240B) is configured to adjust the incident angle of each of the photo subcarriers correspondingly according to the feedback signal input by the feedback processing module.
  • the transmitting end adds an identification signal to each of the polarization multiplexing modulated signals of each photonic carrier, and the feedback processing module calculates the identification signal detected from the signal outputted by the PBS, and calculates and characterizes the polarization state according to the identification signal.
  • Feedback signal feedback to the PC.
  • the identification signal is a perturbation signal added at the transmitting end, and the identification signal detected from the partial signal outputted from the PBS is used to calculate an incident angle of the optical signal entering the polarization beam splitter PBS, and the incoming polarization splitting is performed. The incident angle of the optical signal of the PBS is adjusted.
  • the feedback signal includes a feature characterizing the polarization state, and the feature is extracted in the feedback processing module.
  • the plurality of outputs of the feedback processing module respectively set an initial value, and then the values of the outputs are compared, and each extracted is compared.
  • the proximity of the feature to the feature pre-joined by the sender according to the optimization algorithm, continuously changes the plurality of outputs of the feedback processing module, and finally adjusts the optical signal to the extracted feature quantity closest to the feature pre-joined by the transmitting end.
  • the photo subcarrier separator 210 includes:
  • a power dividing module 301 configured to separate the optical carrier into two or more optical signals
  • Two or more filters (302A, 302B) of different center frequencies are used to filter different optical signals of each of the separated optical signals, and output two or more photo subcarriers with different wavelengths. Signal.
  • the optical carrier is divided into two or more optical signals by a splitter module 301, and then each optical signal is separately filtered into a filter, and the filter 1 and the filter 2 have different center frequencies, so that the filter outputs Signal 1 and signal 2 are two optical signals of different wavelengths, which realize separation of subcarriers.
  • Each of the separated photon carrier signals is separately photo-polarized and multiplexed by a polarization beam splitter PBS, and X-polarized and Y-polarized optical signals to be demodulated are respectively obtained, and the optical signals to be demodulated are respectively demodulated and output.
  • the demodulator used in the apparatus for optically depolarizing multiplexed optical carriers is a differential quadrature phase shift keying DQPSK demodulator (450A, 450B, 450C, 450D).
  • the DQPSK (Differential Quadrature Phase Shifted Keying) demodulator is demodulated for each optical signal to be demodulated, and the delayed coherent demodulation is performed directly on the optical wave to remove the carrier to obtain phase difference information, and finally the phase difference information is obtained.
  • De-mapping obtains information bits.
  • QPSK is a demodulator that modulates the carrier phase.
  • Two signals (bit sequences) have four possibilities: 00, 01, 10, and 11.
  • the carrier selects four different phases. , that is, the phase and the information bit - corresponding.
  • DQPSK is a difference in the QPSK cornerstone, so that the difference between the phases of the signals at the two times before and after corresponds to the transmission sequence, that is, the phase difference between the front and back signals and the information bits-corresponding, DQPSK can be directly on the light wave compared with QPSK.
  • Delay coherent remove the carrier, directly obtain the phase difference information, and then demodulate the information bits, while QPSK can not delay the coherent demodulation.
  • the apparatus for optically depolarizing a multiplexed optical carrier provided by the embodiment of the present invention further includes:
  • the N-level polarization control module PC is configured to adjust an incident angle of the optical signal entering the N-stage variable delay line according to the feedback signal input by the feedback processing module;
  • An N-level variable delay line configured to control a polarization mode dispersion PMD compensation amount of the variable delay line according to a feedback signal input by the feedback processing module, and a polarization mode dispersion PMD for each photonic carrier
  • the N is a positive integer greater than or equal to 1.
  • the feedback processing module feeds back the signals output by the PBS to the N-stage PC and the N-level variable delay line respectively, detects the characteristic PMD signal from the feedback signal, and detects and characterizes the PMD signal for calculating the PMD compensation amount, so that the PC can adjust the entry.
  • the incident angle of the optical signal of the variable delay line is controlled by the variable delay line, that is, the amount of delay of entering the variable delay line.
  • the level of compensation PMD N is determined based on the size of the actual system affected by PMD. If the system is greatly affected by PMD, multi-stage PMD compensation is required. If the system is less affected by PMD, PMD compensation can select less stage PC and variable delay line compensation, or do not need to do PMD compensation. .
  • the apparatus for optically depolarizing and multiplexing two-photon subcarriers separates an optical carrier into two or more photo subcarrier signals at a receiving end by a photo subcarrier separator, and each photonic carrier signal is photoresolved by a PBS.
  • a feedback processing module extracts a partial signal from each of the to-be-demodulated optical signals multiplexed by the PBS photo-depolarization to calculate a characteristic of the polarization state, and controls the feedback according to the feature.
  • the signal is input to the polarization control module PC, and the incident angle of each of the photonic carriers is correspondingly adjusted by the PC.
  • the device that combines two or more subcarriers and photo depolarization multiplexing can make the light
  • the carrier is decomposed into four or more channels in the optical modulation format, and the line speed is reduced to less than 1/4 of the original.
  • the spectrum utilization of the system can be further improved, and the chromatic dispersion CD and the polarization mode dispersion PMD are improved.
  • the N-level polarization control module PC and the N-level variable delay line are used to perform N-level compensation for the polarization mode dispersion PMD of each photonic carrier, and each of the to-be-demodulated optical signals formed by the DQPSK demodulator pair is directly Delayed interference detection on the optical wave results in an output signal, which can further improve the spectrum utilization of the system.
  • an embodiment of the present invention further provides a method for optically depolarizing a multiplexed optical carrier, including: Step 501: Separating an optical carrier into two or more optical subcarrier signals at a receiving end;
  • the optical carrier is separated into two or more optical signals by a power splitting module (Splitter) in the photonic carrier separator, and then each of the optical signals is separately filtered by a filter of different center frequencies to output wavelengths. Different two or more photo subcarrier signals.
  • a power splitting module splitter
  • one method is: separating the optical carrier into two or more photo subcarriers at the transmitting end, and separately modulating two polarization multiplexed modulated signals for each photo subcarrier.
  • the modulated two-way polarization multiplexed modulated signals are combined and combined, and then combined and outputted by an optical carrier.
  • the light source LD601 (Laser) emits a standard wavelength optical carrier (SC, Sub-Carrier), and is modulated by a modulator 602 (Modulator, Mod) to generate two non-standards.
  • SC-A and SC-B in order to avoid inter-code crosstalk (ISI) between different wavelengths, the center frequencies of the two subcarriers must be separated, and the center frequencies of the two subcarriers SC-A and SC-B can be selected.
  • the difference is 20 GHz.
  • the frequency difference is too much a waste of frequency-submarine. 20 GHz is a good compromise between spectrum utilization and overcoming crosstalk between codes.
  • the comb filters 603 are used to separate the subcarriers of the two different center frequencies, and the orthogonal characteristics of the X and Y polarization states are used to respectively polarize each subcarrier.
  • the beam splitter PBS (604A, 604B) is polarization-multiplexed into X-polarized and Y-polarized signals, and respectively modulated by the modulator to obtain four modulated signals.
  • the amount of information per unit time is changed to four times, and then the polarization combiner
  • the PBCs (606A, 606B) are respectively combined, and finally the two sub-carriers are combined by the two polarization multiplexing (PDM) modulated photon carrier multiplexers of the 607 (coupler) 4 bar to obtain a two-photon carrier PDM modulated signal.
  • PDM polarization multiplexing
  • the laser generates a standard wavelength that conforms to the ITU standard. If it is a signal, the signal is modulated to the standard wavelength. Since two-photon carriers need to be generated, two carriers are required, and the two carriers are respectively located at the original standard wavelength. On both sides, there is a certain wavelength difference from the standard wavelength, so it is called a non-standard wavelength.
  • a Mach-Zehnder modulator (MZM) can be used to obtain two photon carriers with a center frequency difference of 20 GHz.
  • the X-polarized and Y-polarized signals that are polarization-multiplexed for each subcarrier can also be
  • the DQPSK modulators (605A, 605B, 605C, and 605D) shown in FIG. 6 are respectively modulated into polarization-multiplexed DQPSK signals, and then combined and then combined to perform dual-photon carrier.
  • the PDM-DQPSK signal is output.
  • Step 502 Demultiplexing two optical signals to be demodulated by optically demultiplexing each optical subcarrier signal.
  • An optimized embodiment if the output is performed by a two-photon subcarrier PDM-DQPSK signal at the transmitting end, at the receiving end, the four demodulated optical signals after depolarization multiplexing are respectively demodulated by a DQPSK demodulator. The delay coherent demodulation is performed directly on the optical wave, the carrier is removed, the phase difference information is obtained, and finally the information bits are obtained by de-mapping the phase difference information.
  • Step 503 Extract a partial signal from each of the to-be-demodulated optical signals to calculate a characteristic indicating a polarization state, and control a feedback signal according to the feature, and adjust a polarization state of each of the photo subcarriers correspondingly.
  • the feedback processing method adopted by the embodiment of the present invention is: adding, by the transmitting end, an identification signal (a perturbation signal) to each of the polarization multiplexing modulated signals of each photonic carrier signal, and the identification signal can perform polarization reconstruction on each photo subcarrier. Add before modulation, during modulation, or after modulation.
  • a partial signal is extracted from each of the to-be-demodulated optical signals to calculate a characteristic characterizing the polarization state, and the feedback signal is controlled according to the feature.
  • the partial signal outputted by the PBS is calculated and processed by the feedback processing module and fed back to the PC, and the identification signal is detected from the feedback signal, and the proximity of each extracted feature to the feature pre-joined by the transmitting end is compared, and optimized.
  • the algorithm continuously changes the multiple outputs of the feedback processing module, and finally adjusts the optical signal to the extracted feature quantity closest to the feature pre-added by the transmitting end.
  • the incident angle of the optical signal entering the polarization beam splitter PBS is calculated based on the identification signal, and the incident angle of the optical signal entering the polarization beam splitter PBS is adjusted by the polarization control module PC, respectively.
  • an N-stage PC and an N-stage variable delay line may be added before the polarization beam splitter PBS at the receiving end, from each of the to-be-demodulated lights. Extracting part of the signal to calculate the polarization mode dispersion PMD compensation amount of each photon carrier, corresponding to the incident angle of the optical signal entering the variable delay line through the polarization control module PC, and respectively performing polarization mode dispersion on each of the photo subcarriers PMD performs N-level compensation, and the N is greater than or equal to 1 Positive integer.
  • PMD Level N is determined based on the size of the actual system affected by PMD. If the system is greatly affected by PMD, multi-stage PMD compensation is required, and if the system is less affected by PMD, PMD compensation can select less stages of PC and variable delay line compensation, or do not need to do PMD compensation. .
  • the method for optically depolarizing a multiplexed optical carrier provided by the embodiment of the present invention, by separating the optical carrier into two or more photo subcarrier signals at the receiving end, respectively, optically demultiplexing each optical subcarrier signal into two demodulated signals to be demodulated
  • the optical signal extracts a part of the signal to be demodulated from each of the signals to calculate a characteristic of the polarization state, and controls the feedback signal according to the characteristic to adjust the polarization state of each of the photo subcarriers correspondingly, so that the optical carrier signal can be made. Decomposed into 4 channels or more in the optical modulation format, and the line speed is reduced to 1/4 or less.
  • the spectrum utilization ratio of the system can be further improved, and the chromatic dispersion CD and the polarization mode dispersion PMD capacity can be improved.
  • the optical depolarization multiplexing can be performed in the form of light waves without complicated calculations, which reduces the device requirements and complexity on the receiving end.
  • N-level compensation is performed on the polarization mode dispersion PMD of each photonic carrier, and the DQPSK demodulator is used to perform delayed interference detection on the optical wave to obtain an output signal, which can further improve the system. Spectrum utilization.
  • an embodiment of the present invention further provides a system for optically depolarizing a multiplexed optical carrier, comprising: a transmitting end device 710, configured to separate an optical carrier into two or more photo subcarrier signals at a transmitting end, for each path
  • the photon carrier signals respectively modulate two polarization-multiplexed modulated signals, and the polarization-multiplexed modulated signals are respectively combined and combined, and then outputted by the optical carrier;
  • the receiving end device 720 is configured to separate the optical carrier into two or more photo subcarrier signals at the receiving end, and respectively optically demultiplex two optical signals to be demodulated for each optical subcarrier signal, and each path is to be solved.
  • the partial signal is extracted from the dimming signal to calculate a characteristic characterizing the polarization state, and the polarization state of each of the photo subcarriers is correspondingly adjusted according to the characteristic control feedback signal.
  • the light source emits a single optical carrier, which is modulated by the modulator to generate photon carriers of two or more different wavelengths, and the sub-carriers of the different center frequencies are separated by a combing filter, and X,
  • the orthogonality of the Y polarization state is decomposed into X-polarized and ⁇ -polarized optical carriers by the polarization beam splitter PBS, and modulated by the modulator, respectively, and then combined by the polarization combiner PBC.
  • the combiner combines the output and still outputs it on the optical carrier.
  • the optical subcarrier separator is used to separate the optical carrier into two or more photo subcarriers at the receiving end.
  • the photo subcarrier separator first separates the optical carrier into two or more optical signals, and then filters each optical signal by a different center frequency.
  • the device performs filtering to output two or more photo subcarrier signals having different wavelengths; and optically demultiplexing each optical subcarrier signal to form four or more optical signals to be demodulated.
  • the identification signal is respectively added to the polarization multiplexing modulated signal of each photonic carrier signal; the identification signal is detected from the extracted partial signal at the receiving end, and the light entering the polarization beam splitter PBS is calculated according to the identification signal.
  • the incident angle of the signal is controlled according to the incident angle, and the incident angle of the optical signal entering the polarizing beam splitter PBS is adjusted and aligned correspondingly by the polarization control module PC, thereby improving the spectrum utilization rate of the system.
  • the receiving end device extracts a partial signal from each of the to-be-demodulated optical signals, and calculates a polarization mode dispersion PMD compensation amount of each photonic carrier, and controls feedback according to the PMD compensation amount.
  • the signal is respectively N-level compensated for the polarization mode dispersion PMD of each photonic carrier, and the N is a positive integer greater than or equal to 1.
  • the specific method may be: adding a N-stage PC and an N-stage variable delay line before the polarization beam splitter PBS at the receiving end, and the feedback processing module extracts a part of the signal from the output signal of the PBS for calculating the polarization mode dispersion of each photonic carrier.
  • PMD compensation amount and according to the PMD compensation amount control feedback signal, respectively fed back to each stage PC and various variable delay lines, the PC adjusts the incident angle of the optical signal entering the variable delay line, by the variable delay line Control the amount of PMD compensation.
  • the selection of the compensated PMD level N is determined by the size of the actual system affected by the PMD. If the system is greatly affected by PMD, multi-stage PMD compensation is required, and if the system is less affected by PMD, PMD compensation can select less stages of PC and variable delay line compensation, or do not need to do PMD compensation. .
  • the DQPSK modulation signal may be separately modulated by using the DQPSK modulator for each of the photo subcarrier signals in the transmitting device; for each channel to be demodulated in the receiving device
  • the optical signal is demodulated by the DQPSK demodulator, and the delayed coherent demodulation is performed directly on the optical wave, the carrier is removed, the phase difference information is obtained, and finally the information bits are obtained by de-mapping the phase difference information.
  • the method, device and system for optically depolarizing multiplexed optical carrier provided by the embodiments of the present invention are described in detail above.
  • the present invention mainly divides an optical carrier into two or more photo subcarriers at the receiving end, and each optical subcarrier is used.
  • the polarization state of the carrier is adjusted, so that the optical carrier signal can be decomposed into four or more channels in the optical modulation format for processing, and the optical depolarization multiplexing can be completed in the form of light wave without complicated calculation, thereby improving the spectrum utilization ratio of the system.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optical Communication System (AREA)

Description

一种光解偏振复用光载波的方法、 装置和系统 本申请要求了 2008年 10月 22日提交的、 申请号为 200810167346.5、 发 明名称为 "一种光解偏振复用光载波的方法、 装置和系统" 的中国申请的优 先权， 其全部内容通过引用结合在本申请中。
技术领域
本发明涉及光通信技术领域， 具体而言是涉及一种光解偏振复用光载波 的方法、 装置和系统。 背景技术
随着光通信技术的发展， 单信道速率日益提高， 目前已经达到或超过 40Gbps , 速率的提高必然对系统的频谱利用率， 光电器件以及对色度色散 ( Chromatic Dispersion, CD )、偏振模色散 ( Polarization Mode Dispersion, PMD ) 的容限有了更高的要求。
参见图 1 , 现有技术中， 一光载波的偏振复用调制信号在接收端由偏振分 束器 101 ( Polarization Beam Splitter, PBS )光解偏振复用得到信号 xl和 x2。 采用最小均方误差估计 MSE算法 105 , 由解复用器 DMUX102对信道的逆矩 阵进行估计，信道逆矩阵估计由解调后信号的均方误差 al和 a2控制，解复用 器 DMUX102输出信号 yl和 y2; 将 yl与 y2分别通过光电二极管 （ 103A、 103B )转换为电信号 si、 s2后， 被接收机 RX ( 104A、 104B )解调输出， 由 接收机 RX实现对信号的解调功能。
现有技术采用的是对光载波进行偏振复用来提高系统的频谱利用率， 将 偏振复用调制信号转换为电信号后再进行解调， 并以解调信号的均方差作为 反馈信号来控制 DMUX解复用器的各种参数， 对模数转换器（ADC, Analog to Digital Convertor )和其他器件的要求非常高； 而且由于单载波偏振复用是 分 2路传输信号， 每路信号的速率仍会非常高， 即使通过码型、 滤波器调整 可以在一定程度提高频谱利用率， 但这种提高非常有限， 并且很容易带来对 信号的损伤。 发明内容
有鉴于此， 本发明实施例提供了一种光解偏振复用光载波的方法、 装置 和系统， 能够提高系统的频谱利用率， 提高色度色散 CD和偏振模色散 PMD容 限， 同时降低对接收端的器件要求和复杂度。
为实现上述目的， 本发明实施例是通过如下技术方案实现的：
一方面， 提供一种光解偏振复用光载波的方法， 包括：
在接收端将光载波分离成两路以上光子载波；
对每路光子载波分别光解偏振复用出两路待解调光信号；
从每路待解调光信号中提取部分信号计算表征偏振状态的特征， 根据所 述特征控制反馈信号， 对应地对所述每路光子载波的偏振状态进行调节。
另一方面， 提供一种光解偏振复用光载波的装置， 包括：
光子载波分离器， 用于在接收端将光载波分离为两路以上光载波； 偏振分束器 PBS,用于对所述光子载波分离器分离出的每路光子载波分别 光解偏振复用出两路待解调光信号；
反馈处理模块， 用于从所述偏振分束器 PBS光解偏振复用出的每路待解 调光信号中提取部分信号计算表征偏振状态的特征， 根据所述特征控制反馈 信号输入至偏振控制模块 PC;
偏振控制模块 PC, 用于根据所述反馈处理模块输入的反馈信号， 对应地 对所述每路光子载波的入射角进行调节。
再一方面， 提供一种光解偏振复用光载波的系统， 包括：
发送端装置， 用于在发送端将光载波分离成两路以上光子载波信号， 对 每路光子载波信号分别调制出两路偏振复用调制信号， 将所述偏振复用调制 信号分别对应合束后再进行合波， 仍以光载波进行输出；
接收端装置， 用于在接收端将光载波分离成两路以上光子载波信号， 对 每路光子载波信号分别光解偏振复用出两路待解调光信号， 从每路待解调光 信号中提取部分信号计算表征偏振状态的特征， 根据所述特征控制反馈信号， 对应地对所述每路光子载波的偏振状态进行调节。
由以上技术方案可知， 通过在接收端将光载波分离为两路以上光子载波， 对每路光子载波分别光解偏振复用出两路待解调光信号， 从每路待解调光信 号中提取部分信号计算表征偏振状态的特征， 根据所述特征控制反馈信号， 对应地对所述每路光子载波的偏振状态进行调节， 可以使光载波信号在光调 制格式下分解为 4路以上，将线路速率降低到原来的 1/4以下， 从而能够提高系 统的频谱利用率， 提高色度色散 CD和偏振模色散 PMD容限， 同时无需经过复 杂的计算即可在光波形式下完成光解偏振复用， 降低对接收端器件的要求和 复杂度。 附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案， 下面将对实 施例或现有技术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， 对于本领域普通技术人员来讲， 在不付出创造性劳动性的前提下， 还可以根据这些附图获得其他的附图。
图 1为现有技术的光解偏振复用接收端装置的结构图；
图 2为本发明实施例提供的光解偏振复用光载波的装置结构图； 图 3为本发明实施例提供的光子载波分离器结构图；
图 4为本发明实施例提供的一种优化光解偏振复用光载波的装置结构图； 图 5为本发明实施例提供的光解偏振复用光载波的方法流程图； 图 6为本发明实施例提供的发送端生成光载波的装置结构图；
图 7为本发明实施例提供的光解偏振复用光载波的系统示意图。 具体实施方式
下面结合附图对本发明实施例提供的技术方案进一步详细描述。 需要说 明的是， 为了叙述的方便， 本发明实施例的技术方案是将光载波分离成两路 光子载波进行说明， 本领域的技术人员完全可以理解将光载波分离成两路以 上光子载波都应涵盖在本发明的保护范围之内。
参见图 2,图 2为本发明实施例提供的光解偏振复用光载波的装置，包括： 光子载波分离器 210, 用于在接收端将光载波分离为两路以上光子载波； 偏振分束器 PBS ( 220A、 220B ), 用于对所述光子载波分离器 210分离 出的每路光子载波分别光解偏振复用出两路待解调光信号；
反馈处理模块（230A、 230B ), 用于从所述偏振分束器 PBS光解偏振复 用出的每路待解调光信号中提取部分信号计算表征偏振状态的特征， 根据所 述特征控制反馈信号输入至偏振控制模块 PC;
偏振控制模块 PC ( 240A、 240B ), 用于根据所述反馈处理模块输入的反 馈信号， 对应地对所述每路光子载波的入射角进行调节。
例如， 在发送端向每路光子载波的偏振复用调制信号分别加入标识信号， 反馈处理模块将从 PBS输出的信号中检测出的该标识信号， 根据该标识信号 计算表征偏振状态的特征并控制反馈信号， 反馈至 PC。
该标识信号是在发送端加入的微扰信号， 从 PBS输出的部分信号中检测 出的该标识信号用于计算进入偏振分束器 PBS的光信号的入射角， 并对所述 进入偏振分束器 PBS的光信号的入射角进行调节。
反馈信号中包含有表征偏振状态的特征， 在反馈处理模块中提取出这种 特征， 反馈处理模块的多个输出分别设定一个初值， 然后通过改变这些输出 的值， 比较每次提取出来的特征与发送端预加入的特征的接近状况， 按照最 优化算法， 不断改变反馈处理模块的多个输出， 最终将光信号调整到提取的 特征量与发送端预加入的特征最接近。
参见图 3 , 所述光子载波分离器 210包括：
功分模块 301 , 用于将所述光载波分离成两束以上光信号；
两个以上不同中心频率的滤波器（302A、 302B ), 用于对所述分离后的每 束光信号分别进行不同中心频率的滤波， 输出波长不同的两路以上光子载波 信号。
光载波经功分模块（splitter ) 301分为两束以上光信号， 然后对每束光信 号分别进入滤波器进行滤波处理， 滤波器 1和滤波器 2有不同的中心频率， 从而滤波器输出的信号 1和信号 2为不同波长的两束光信号， 实现了子载波 的分离。
分离后的每路光子载波信号， 分别用偏振分束器 PBS光解偏振复用， 分 别得到 X偏振和 Y偏振的待解调光信号， 对这些待解调光信号分别进行解调 后输出。
一种优化实施例， 参见图 4, 本发明实施例提供的光解偏振复用光载波的 装置采用的解调器为差分四相相移键控 DQPSK解调器（450A、 450B、 450C、 450D ),对每路待解调光信号使用 DQPSK( Differential Quadrature Phase Shifted Keying )解调器进行解调， 直接在光波上进行延时相干解调， 去除载波， 得 到相位差信息， 最后由相位差信息解映射得到信息比特。
QPSK是对载波相位进行调制的解调器， 两路信号 （比特序列）， 共有 4 种可能： 00、 01、 10、 11 , 根据这两路信号比特序列的不同， 载波选择 4种 不同的相位，即相位与信息比特——对应。 DQPSK是在 QPSK基石出上做差分， 使前后两个时刻信号的相位的差值对应于发送序列， 即前后信号的相位差与 信息比特——对应， DQPSK比起 QPSK, 可以直接在光波上进行延时相干， 去除载波， 直接得到相位差信息， 然后解调出信息比特， 而 QPSK则不能延 时相干解调。
一种优化实施例， 仍参见图 4, 本发明实施例提供的光解偏振复用光载波 的装置还包括：
N级个偏振控制模块 PC, 用于根据所述反馈处理模块输入的反馈信号， 对应调节进入 N级可变延时线的光信号入射角；
N 级可变延时线， 用于根据所述反馈处理模块输入的反馈信号， 控制可 变延时线的偏振模色散 PMD补偿量，对所述每路光子载波的偏振模色散 PMD 对应进行 N级补偿， 所述的 N为大于等于 1的正整数。
反馈处理模块将 PBS输出的信号分别反馈至 N级 PC与 N级可变延时线， 从反馈信号中检测出表征 PMD信号， 检测表征 PMD信号用于计算 PMD补 偿量， 从而由 PC 调节进入可变延时线的光信号入射角， 由可变延时线控制 PMD补偿量， 即进入可变延时线的延时量。
补偿 PMD的级别 N的选取是根据实际系统受 PMD影响的大小来决定。 如果系统受 PMD影响较大， 则需要多级的 PMD补偿， 而如果系统受 PMD 影响较小， 则 PMD补偿可以选择较少级数的 PC与可变延时线补偿， 或者是 不用做 PMD补偿。
本发明实施例提供的光解偏振复用双光子载波的装置， 通过光子载波分 离器在接收端将光载波分离为两路以上光子载波信号， 由 PBS对每路光子载 波信号分别光解偏振复用出两路待解调光信号，并由反馈处理模块从所述 PBS 光解偏振复用出的每路待解调光信号中提取部分信号计算表征偏振状态的特 征， 根据所述特征控制反馈信号输入至偏振控制模块 PC, 由所述 PC对应地 对所述每路光子载波的入射角进行调节， 这种光解两路以上子载波与光解偏 振复用相结合的装置， 可以使光载波在光调制格式下分解为 4路以上， 将线 路速度降低到原来的 1/4以下， 与现有技术相比， 能够进一步提高系统的频谱 利用率， 提高色度色散 CD和偏振模色散 PMD容限， 而且无需经过复杂的计 算即可在光波形式下完成光解偏振复用， 降低了对接收端的器件要求和复杂 度。 同时， 使用 N级偏振控制模块 PC与 N级可变延时线对每路光子载波的 偏振模色散 PMD进行 N级补偿，以及使用 DQPSK解调器对形成的每路待解 调光信号直接在光波上进行延时干涉检测得到输出信号， 可以进一步提高系 统的频谱利用率。
参见图 5,本发明实施例还提供了一种光解偏振复用光载波的方法，包括： 步骤 501 , 在接收端将光载波分离为两路以上光子载波信号；
在接收端使用光子载波分离器将光载波分离为两路以上光子载波信号， 首先由光子载波分离器中的功分模块（Splitter )将所述光载波分离成两束以 上光信号后， 再由不同中心频率的滤波器对所述每束光信号分别进行滤波处 理， 输出波长不同的两路以上光子载波信号。
为了得到符合需要的偏振复用调制后的光载波接收信号， 一种方法是： 在发送端将光载波分离成两路以上光子载波， 对每路光子载波分别调制出两 路偏振复用调制信号， 将所述调制出的两路偏振复用调制信号分别对应合束 后再进行合波， 仍以光载波进行输出。
下面对发送端的装置进行说明， 参见图 6, 光源 LD601 ( Laser Diode, 激 光器）发出标准波长的光载波（ SC, Sub-Carrier ),经过调制器 602 ( Modulator, Mod )调制产生两个非标准波长的光子载波 SC-A和 SC-B, 为避免不同波长 之间的码间串扰（ISI ), 两子载波的中心频率必须分开， 可以选择两子载波 SC-A和 SC-B 的中心频差为 20GHz, 频差太大势必是对频-潜的一种浪费， 20GHz是在频谱利用率和克服码间串扰的一个较好折中。
对于 Mod调制生成的两光子载波， 采用梳状滤波器 603 ( IL , Interleaver ) 将这两个不同中心频率的子载波分离， 利用 X、 Y偏振态的正交特性， 对每 路子载波分别由偏振分束器 PBS ( 604A、 604B )偏振复用为 X偏振和 Y偏振 信号， 并分别经过调制器调制共得到 4路调制信号， 单位时间的信息量变为 原来的 4倍， 再由偏振合束器 PBC ( 606A、 606B )分别合束， 最后由合波器 607 ( Coupler ) 4巴这两个偏振复用 （ Polarization Division Multiple , PDM )调 制后的光子载波合波输出 , 得到双光子载波 PDM调制信号。
需要说明的是， 激光器产生符合 ITU规定的标准波长， 如果是一路信号， 信号被调制到这个标准波长上； 由于需要生成双光子载波， 需要 2路载波， 这两路载波分别位于原来的标准波长两边， 与标准波长存在一定波长差， 因 此称为非标准波长。 可以采用马赫-曾德尔调制器（MZM )得到中心频差为 20 GHz的两光子载波。
还需要说明的是， 对每路子载波偏振复用的 X偏振和 Y偏振信号还可以 采用如图 6所示的 DQPSK调制器（605A、 605B、 605C、 605D ), 分别调制 成偏振复用的 DQPSK信号， 然后分别合束后再进行合波， 以双光子载波
PDM-DQPSK信号进行输出。
步骤 502, 对每路光子载波信号分别光解偏振复用出两路待解调光信号。 一种优化实施例， 如果在发送端以双光子载波 PDM-DQPSK信号进行输 出， 则在接收端， 对解偏振复用后的 4路待解调光信号， 分别采用 DQPSK解 调器进行解调， 直接在光波上进行延时相干解调， 去除载波， 得到相位差信 息， 最后由相位差信息解映射得到信息比特。
步骤 503 , 从每路待解调光信号中提取部分信号计算表征偏振状态的特 征， 根据所述特征控制反馈信号， 对应地对所述每路光子载波的偏振状态进 行调节。
本发明实施例采用的反馈处理方法是： 在发送端通过对每路光子载波信 号的偏振复用调制信号分别加标识信号（微扰信号）， 该标识信号可以在对每 路光子载波进行偏振复用调制之前、 调制过程中或调制之后加入。 在接收端 从每路待解调光信号中提取部分信号计算表征偏振状态的特征， 根据该特征 控制反馈信号。 通过由反馈处理模块将 PBS输出的部分信号计算处理后反馈 至 PC中， 从反馈信号中检测出该标识信号， 比较每次提取出来的特征与发送 端预加入的特征的接近状况， 按照最优化算法， 不断改变反馈处理模块的多 个输出， 最终将光信号调整到提取的特征量与发送端预加入的特征最接近。 根据所述标识信号计算进入偏振分束器 PBS的光信号的入射角， 通过偏振控 制模块 PC分别对所述进入偏振分束器 PBS的光信号的入射角进行调节。
为了进一步提高系统的偏振模色散 PMD容限， 一种优选实施例， 可以在 接收端的偏振分束器 PBS之前加入 N级 PC与 N级可变延时线， 从所述每路 待解调光信号中提取部分信号计算每路光子载波的偏振模色散 PMD补偿量， 对应通过偏振控制模块 PC调节进入可变延时线的光信号入射角，同时分别对 所述每路光子载波的偏振模色散 PMD进行 N级补偿，所述的 N为大于等于 1 的正整数。
补偿 PMD级别 N的选取是根据实际系统受 PMD影响的大小来决定。 如 果系统受 PMD影响较大， 则需要多级的 PMD补偿， 而如果系统受 PMD影 响较小， 则 PMD补偿可以选择较少级数的 PC和可变延时线补偿， 或者是不 用做 PMD补偿。
本发明实施例提供的光解偏振复用光载波的方法， 通过在接收端将光载 波分离为两路以上光子载波信号， 对每路光子载波信号分别光解偏振复用出 两路待解调光信号， 从每路待解调光信号中提取部分信号计算表征偏振状态 的特征， 根据所述特征控制反馈信号， 对应地对所述每路光子载波的偏振状 态进行调节， 可以使光载波信号在光调制格式下分解为 4路以上， 将线路速 度降低到原来的 1/4以下， 与现有技术相比， 能够进一步提高系统的频谱利用 率， 提高色度色散 CD和偏振模色散 PMD容限， 而且无需经过复杂的计算即 可在光波形式下完成光解偏振复用， 降低了对接收端的器件要求和复杂度。 同时，对每路光子载波的偏振模色散 PMD进行 N级补偿， 以及对形成的每路 待解调光信号使用 DQPSK解调器直接在光波上进行延时干涉检测得到输出 信号， 可以进一步提高系统的频谱利用率。
参见图 7,本发明实施例还提供了一种光解偏振复用光载波的系统，包括： 发送端装置 710, 用于在发送端将光载波分离成两路以上光子载波信号， 对每路光子载波信号分别调制出两路偏振复用调制信号， 将所述偏振复用调 制信号分别对应合束后再进行合波， 仍以光载波进行输出；
接收端装置 720,用于在接收端将所述光载波分离为两路以上光子载波信 号， 对每路光子载波信号分别光解偏振复用出两路待解调光信号， 从每路待 解调光信号中提取部分信号计算表征偏振状态的特征， 根据所述特征控制反 馈信号， 对应地对所述每路光子载波的偏振状态进行调节。
在发送端， 光源发出一单光载波， 经过调制器调制产生两个以上不同波 长的光子载波， 采用梳妆滤波器将这些不同中心频率的子载波分离， 利用 X、 Y偏振态的正交特性， 对每路子载波分别由偏振分束器 PBS分解为 X偏振和 Υ偏振光载波，并分别经过调制器调制后再由偏振合束器 PBC分别对应合束， 最后由合波器合波输出， 仍以光载波进行输出。
在接收端使用光子载波分离器将光载波分离为两路以上光子载波， 所述 光子载波分离器首先将光载波分离成两束以上光信号后， 对每束光信号分别 由不同中心频率的滤波器进行滤波处理输出波长不同的两路以上光子载波信 号； 对每路光子载波信号分别进行光解偏振复用形成 4路以上待解调光信号。
在发送端通过对每路光子载波信号的偏振复用调制信号分别加入标识信 号； 在接收端从所述提取的部分信号中检测该标识信号， 根据该标识信号计 算进入偏振分束器 PBS的光信号的入射角， 根据所述入射角控制反馈信号， 对应地对所述进入偏振分束器 PBS 的光信号的入射角通过偏振控制模块 PC 进行调节对准，从而能够在提高系统的频谱利用率，提高色度色散 CD和偏振 模色散 PMD容限， 同时降低接收端的器件要求和复杂度。
为进一步提高系统的偏振模色散 PMD容限，所述接收端装置从每路待解 调光信号中提取部分信号计算每路光子载波的偏振模色散 PMD补偿量，根据 所述 PMD补偿量控制反馈信号，分别对所述每路光子载波的偏振模色散 PMD 进行 N级补偿， 所述的 N为大于等于 1的正整数。
具体方法可以为， 在接收端的偏振分束器 PBS之前加入 N级 PC与 N级 可变延时线， 反馈处理模块从 PBS的输出信号中提取部分信号用于计算每路 光子载波的偏振模色散 PMD补偿量， 并根据该 PMD补偿量控制反馈信号， 分别反馈至各级 PC与各级可变延时线， 由 PC调节进入可变延时线的光信号 入射角， 由可变延时线控制 PMD补偿量。
补偿 PMD级别 N的选取是根据实际系统受 PMD影响的大小来决定。 如 果系统受 PMD影响较大， 则需要多级的 PMD补偿， 而如果系统受 PMD影 响较小， 则 PMD补偿可以选择较少级数的 PC和可变延时线补偿， 或者是不 用做 PMD补偿。 为进一步提高系统的频谱利用率， 还可以在发送端装置中对所述每路光 子载波信号使用 DQPSK调制器分别调制出偏振复用的 DQPSK调制信号； 在 接收端装置中对每路待解调光信号使用 DQPSK解调器进行解调，直接在光波 上进行延时相干解调， 去除载波， 得到相位差信息， 最后由相位差信息解映 射得到信息比特。
以上对本发明实施例所提供的光解偏振复用光载波的方法、 装置和系统 进行了详细介绍， 本发明主要是通过在接收端将光载波分离为两路以上光子 载波， 对每路光子载波分别光解偏振复用出两路待解调光信号， 从每路待解 调光信号中提取部分信号计算表征偏振状态的特征， 根据所述特征控制反馈 信号， 对应地对所述每路光子载波的偏振状态进行调节， 可以使光载波信号 在光调制格式下分解为 4路以上去处理， 无需经过复杂的计算即可在光波形 式下完成光解偏振复用， 能够提高系统的频谱利用率，提高色度色散 CD和偏 振模色散 PMD容限， 同时降低接收端的器件要求和复杂度。 实施例的说明只 是用于帮助理解本发明的方法及其思想； 任何熟悉本技术领域的技术人员在 本发明揭露的技术范围内， 可轻易想到变化或替换， 都应涵盖在本发明的保 护范围之内。 因此， 本发明的保护范围应以所述权利要求的保护范围为准。

Claims

权利 要 求 书
1、 一种光解偏振复用光载波的方法， 其特征在于， 包括：
在接收端将光载波分离成两路以上光子载波；
对每路光子载波分别光解偏振复用出两路待解调光信号；
从每路待解调光信号中提取部分信号计算表征偏振状态的特征， 根据所述 特征控制反馈信号， 对应地对所述每路光子载波的偏振状态进行调节。
2、 根据权利要求 1所述的方法， 其特征在于， 所述方法还包括：
在发送端将光载波分离成两路以上光子载波；
对每路光子载波分别调制出两路偏振复用调制信号；
将所述偏振复用调制信号分别对应合束后再进行合波， 以光载波进行输出。
3、 根据权利要求 1所述的方法， 其特征在于， 所述在接收端将光载波分离 成两路以上光子载波信号的步驟包括：
在接收端将光载波分离成两束以上光信号；
对每束光信号分别进行不同中心频率的滤波， 输出波长不同的两路以上光 子载波信号。
4、 根据权利要求 2所述的方法， 其特征在于， 在发送端向所述每路光子载 波的偏振复用调制信号分别加入标识信号；
所述从每路待解调光信号中提取部分信号计算表征偏振状态的特征， 根据 所述特征控制反馈信号， 对应地对所述每路光子载波的偏振状态进行调节包括： 在接收端从所述提取的部分信号中检测所述标识信号， 根据该标识信号计 算每路光子载波的入射角， 根据所述入射角控制反馈信号， 对应地对所述每路 光子载波的入射角进行调节。
5、 根据权利要求 4所述的方法， 其特征在于， 所述从每路待解调光信号中 提取部分信号计算表征偏振状态的特征， 根据所述特征控制反馈信号， 对应地 对所述每路光子载波的偏振状态进行调节还包括： 在接收端从所述提取的部分信号中检测所述标识信号， 根据该标识信号计 算每路光子载波的偏振模色散 PMD补偿量， 根据所述 PMD补偿量控制反馈信 号， 对应地对所述每路光子载波的偏振模色散 PMD进行 N级补偿， 所述的 N 为大于等于 1的正整数。
6、 根据权利要 1所述的方法， 其特征在于， 所述方法还包括：
对调节后的待解调光信号直接在光波上进行延时干涉， 检测得到解调输出 信号。
7、 一种光解偏振复用光载波的装置， 其特征在于， 包括：
光子载波分离器， 用于在接收端将光载波分离成两路以上光子载波； 偏振分束器 PBS, 用于对所述光子载波分离器分离出的每路光子载波分别 光解偏振复用出两路待解调光信号；
反馈处理模块， 用于从所述偏振分束器 PBS光解偏振复用出的每路待解调 光信号中提取部分信号计算表征偏振状态的特征， 根据所述特征控制反馈信号 输入至偏振控制模块 PC;
偏振控制模块 PC, 用于根据所述反馈处理模块输入的反馈信号， 对应地对 所述每路光子载波的入射角进行调节。
8、 根据权利要求 7所述的装置， 其特征在于， 所述装置还包括：
N级偏振控制模块 PC, 用于根据所述反馈处理模块输入的反馈信号， 对应 调节进入 N级可变延时线的光信号入射角；
N 级可变延时线， 用于根据所述反馈处理模块输入的反馈信号， 控制可变 延时线的偏振模色散 PMD补偿量， 对所述每路光子载波的偏振模色散 PMD对 应进行 N级补偿；
所述的 N为大于等于 1的正整数。
9、 根据权利要求 7所述的装置， 其特征在于， 所述光子载波分离器包括： 功分模块， 用于将所述光载波分离成两束以上光信号；
两个以上不同中心频率的滤波器， 用于对所述分离后的每束光信号分别进 行不同中心频率的滤波， 输出波长不同的两路以上光子载波信号。
10、 根据权利要求 7或 8所述的装置， 其特征在于， 所述装置还包括： 差分四相相移键控 DQPSK解调器，用于对所述调节后的待解调光信号直接 在光波上进行延时干涉， 检测得到解调输出信号。
11、 一种光解偏振复用光载波的系统， 其特征在于， 包括：
发送端装置， 用于在发送端将光载波分离成两路以上光子载波信号， 对每 路光子载波信号分别调制出两路偏振复用调制信号， 将所述偏振复用调制信号 分别对应合束后再进行合波， 仍以光载波进行输出；
接收端装置， 用于在接收端将光载波分离成两路以上光子载波信号， 对每 路光子载波信号分别光解偏振复用出两路待解调光信号， 从每路待解调光信号 中提取部分信号计算表征偏振状态的特征， 根据所迷特征控制反馈信号， 对应 地对所述每路光子载波的偏振状态进行调节。
12、 根据权利要求 11所述的系统， 其特征在于，
所述发送端装置， 还用于向所述每路光子载波的偏振复用调制信号分别加 入标识信号；
所述接收端装置， 还用于从所述提取的部分信号中检测所述标识信号， 根 据该标识信号计算每路光子载波的入射角， 根据所述入射角控制反馈信号， 对 应地对所述每路光子载波的入射角进行调节； 以及根据该标识信号计算每路光 子载波的偏振模色散 PMD补偿量， 根据所述 PMD补偿量控制反馈信号， 对应 地对所述每路光子载波的偏振模色散 PMD进行 N级补偿， 所述的 N为大于等 于 1的正整数。
13、 根据权利要求 11或 12所述的系统， 其特征在于，
所述发送端装置，还用于对所述偏振复用调制信号分别使用 DQPSK调制器 调制出偏振复用的 DQPSK调制信号；
所述接收端装置，还用于对调节后的待解调光信号分别使用 DQPSK解调器 直接在光波上进行延时干涉， 检测得到解调输出信号。
PCT/CN2009/072405 2008-10-22 2009-06-23 一种光解偏振复用光载波的方法、装置和系统 WO2010045802A1 (zh)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP09821523A EP2352239A4 (en) 2008-10-22 2009-06-23 METHOD, DEVICE AND SYSTEM FOR THE OPTICAL DEMODULATION OF THE OPTICAL SUPPORT IN POLARIZATION MULTIPLEXING
BRPI0919797A BRPI0919797A2 (pt) 2008-10-22 2009-06-23 método, dispositivo, e sistema para multiplexação de divisão de polarização ótica de portadora ótica.
US13/091,843 US20110206375A1 (en) 2008-10-22 2011-04-21 Method, device, and system for optical polarization division multiplexing of optical carrier

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN200810167346.5 2008-10-22
CN200810167346A CN101729149A (zh) 2008-10-22 2008-10-22 一种光解偏振复用光载波的方法、装置和系统

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US13/091,843 Continuation US20110206375A1 (en) 2008-10-22 2011-04-21 Method, device, and system for optical polarization division multiplexing of optical carrier

Publications (1)

Publication Number Publication Date
WO2010045802A1 true WO2010045802A1 (zh) 2010-04-29

Family

ID=42118923

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2009/072405 WO2010045802A1 (zh) 2008-10-22 2009-06-23 一种光解偏振复用光载波的方法、装置和系统

Country Status (5)

Country Link
US (1) US20110206375A1 (zh)
EP (1) EP2352239A4 (zh)
CN (1) CN101729149A (zh)
BR (1) BRPI0919797A2 (zh)
WO (1) WO2010045802A1 (zh)

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5186993B2 (ja) * 2008-04-30 2013-04-24 富士通株式会社 偏波多重光送受信装置
WO2010061247A1 (en) * 2008-11-28 2010-06-03 Alcatel Lucent Apparatus and method for compensating polarization mode dispersion
KR101382619B1 (ko) * 2009-07-24 2014-04-07 한국전자통신연구원 광 송신 장치 및 방법과 광 수신 장치 및 방법
FR2965992B1 (fr) * 2010-10-08 2014-04-04 Inst Telecom Telecom Paristech Methode et systeme de transmission wdm a codage chromato-temporel
US8693897B2 (en) * 2011-01-22 2014-04-08 Viasat, Inc. Digital demodulator architecture
US8744279B2 (en) 2011-01-22 2014-06-03 Viasat, Inc. Adaptive PMD equalizer and implementation
WO2012100254A2 (en) 2011-01-22 2012-07-26 Viasat, Inc. Frame formatting for high rate optical communications
US8615171B2 (en) * 2011-03-31 2013-12-24 Nec Laboratories America, Inc. Computationally-efficient equalization in polmux OFDM transmission with direct detection via joint transmitter and receiver processing
EP2521289B1 (en) * 2011-05-04 2014-03-05 Alcatel Lucent Optical receiver for multimode communications
US8861960B2 (en) * 2012-08-20 2014-10-14 Ciena Corporation Systems and methods for the compensation of nonlinear cross polarization and cross phase modulation in dual polarization coherent channels
CN103297169B (zh) * 2013-06-26 2015-06-24 武汉邮电科学研究院 基于梳状光源再生技术的ofdm-pon长距离传输方法
CN104243047B (zh) * 2014-09-19 2018-01-12 电子科技大学 一种pdm‑dqpsk/sac光标记交换系统
US10382139B2 (en) * 2016-12-21 2019-08-13 Ceragon Networks Ltd. Polarization pre-coding for a single carrier communication system
US10833767B2 (en) * 2018-01-24 2020-11-10 Indian Institute Of Technology Bombay Self-homodyne carrier multiplexed transmission system and method for coherent optical links
CN113206703B (zh) * 2021-04-19 2022-06-03 烽火通信科技股份有限公司 一种波分复用的色度色散和偏振模色散监测方法及装置
CN113938624B (zh) * 2021-10-15 2022-06-07 北京邮电大学 一种多载波系统中载波串扰与偏振串扰联合补偿方法
CN114584212B (zh) * 2022-04-15 2023-12-08 中国电子科技集团公司第三十四研究所 一种特征相似度分析的调制格式与光信噪比监测方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1298826A2 (de) * 2001-09-28 2003-04-02 Siemens Aktiengesellschaft Verfahren zur Übertragung von mindestens einem ersten und zweiten Datensignal im Polarisationsmultiplex in einem optischen Übertragungssystem
CN1734312A (zh) * 2004-05-28 2006-02-15 姚晓天 基于偏振复用技术的光通信系统
CN1977477A (zh) * 2004-03-09 2007-06-06 爱立信股份有限公司 偏振模式色散补偿和对偏振复用信号解复用的系统、方法及设备

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000072492A1 (en) * 1999-05-20 2000-11-30 University Of Southern California Polarization-division multiplexing based on power encoding of different polarization channels
US6525857B1 (en) * 2000-03-07 2003-02-25 Opvista, Inc. Method and apparatus for interleaved optical single sideband modulation
US6856459B1 (en) * 2000-12-22 2005-02-15 Cheetah Omni, Llc Apparatus and method for controlling polarization of an optical signal
US7035543B1 (en) * 2001-05-10 2006-04-25 Fujitsu Limited Method and system for demultiplexing non-intensity modulated wavelength division multiplexed (WDM) signals
JP2003338805A (ja) * 2002-03-15 2003-11-28 Kddi Submarine Cable Systems Inc 光伝送システム、光送信装置及びこれらの方法
US7266310B1 (en) * 2003-04-29 2007-09-04 Nortel Networks Limited Digital compensation for optical transmission system
US7450863B2 (en) * 2003-06-18 2008-11-11 Lucent Technologies Inc. Optical receiver for wavelength-division-multiplexed signals
US7315584B1 (en) * 2003-12-17 2008-01-01 Nortel Networks Limited Coherent receiver
US6917031B1 (en) * 2004-02-17 2005-07-12 Nortel Networks Limited Method for quadrature phase angle correction in a coherent receiver of a dual-polarization optical transport system
US7724987B2 (en) * 2004-12-13 2010-05-25 Fujitsu Limited Method and apparatus for dynamic polarization control

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1298826A2 (de) * 2001-09-28 2003-04-02 Siemens Aktiengesellschaft Verfahren zur Übertragung von mindestens einem ersten und zweiten Datensignal im Polarisationsmultiplex in einem optischen Übertragungssystem
CN1977477A (zh) * 2004-03-09 2007-06-06 爱立信股份有限公司 偏振模式色散补偿和对偏振复用信号解复用的系统、方法及设备
CN1734312A (zh) * 2004-05-28 2006-02-15 姚晓天 基于偏振复用技术的光通信系统

Also Published As

Publication number Publication date
EP2352239A1 (en) 2011-08-03
EP2352239A4 (en) 2012-07-04
CN101729149A (zh) 2010-06-09
US20110206375A1 (en) 2011-08-25
BRPI0919797A2 (pt) 2015-12-15

Similar Documents

Publication Publication Date Title
WO2010045802A1 (zh) 一种光解偏振复用光载波的方法、装置和系统
Winzer Beyond 100G ethernet
Jansen et al. 121.9-Gb/s PDM-OFDM transmission with 2-b/s/Hz spectral efficiency over 1000 km of SSMF
US8909066B2 (en) Optical transfer system, optical transmission device, and optical reception device
Chandrasekhar et al. Terabit superchannels for high spectral efficiency transmission
US10735103B2 (en) Reception device, transmission device, optical communication system and optical communication method
WO2013114629A1 (ja) 光伝送システムおよび光信号伝送方法
EP2559173B1 (en) Method and device for transmission and reception of a polarization multiplexed optical signal
US9246735B2 (en) Equalizing a signal modulated using a 5QAM modulation format
US8270847B2 (en) Polarization multiplexing with different DPSK modulation schemes and system incorporating the same
Huang et al. Transmission of spectral efficient super-channels using all-optical OFDM and digital coherent receiver technologies
Liu et al. Superchannel for next-generation optical networks
TW201214997A (en) Tunable receiver
WO2019042371A1 (zh) 光信号传输系统及光信号传输方法
WO2013143976A1 (en) Flexible optimization of the signal-to-noise ratio for ultra dense coherent wdm systems
US8724999B2 (en) POLMUX-OFDM-DD transmitter and receiver for reduced complexity and overhead in optical access/metro transmission
WO2010017366A1 (en) Frequency offset polarization multiplexing modulation format and system incorporating the same
US11863297B1 (en) Systems and methods for carrier phase recovery
US20120263468A1 (en) Generation of Optical Quadrature Duobinary Format Using Optical Delay
Freund et al. Single-and multi-carrier techniques to build up Tb/s per channel transmission systems
EP2204928B1 (en) Method and device for receiving OPFDM-DQPSK signal
EP3105872B1 (en) Transmitter apparatus and method
EP2873182B1 (en) Method and device for signal processing in an optical communication network
Mahdiraji et al. Advanced modulation formats and multiplexing techniques for optical telecommunication systems
Chandrasekhar et al. Advances in Tb/s superchannels

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09821523

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2009821523

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: PI0919797

Country of ref document: BR

Kind code of ref document: A2

Effective date: 20110420