Nothing Special   »   [go: up one dir, main page]

WO2013136651A1 - Optical communications system, optical transmission device, optical reception device, optical communications method, optical transmission method, phase rotation setting device, and optical reception method - Google Patents

Optical communications system, optical transmission device, optical reception device, optical communications method, optical transmission method, phase rotation setting device, and optical reception method Download PDF

Info

Publication number
WO2013136651A1
WO2013136651A1 PCT/JP2013/000387 JP2013000387W WO2013136651A1 WO 2013136651 A1 WO2013136651 A1 WO 2013136651A1 JP 2013000387 W JP2013000387 W JP 2013000387W WO 2013136651 A1 WO2013136651 A1 WO 2013136651A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical
transmission
optical signal
phase rotation
signal
Prior art date
Application number
PCT/JP2013/000387
Other languages
French (fr)
Japanese (ja)
Inventor
慎介 藤澤
大作 小笠原
透 高道
Original Assignee
日本電気株式会社
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 日本電気株式会社 filed Critical 日本電気株式会社
Publication of WO2013136651A1 publication Critical patent/WO2013136651A1/en

Links

Images

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
    • H04B10/50—Transmitters
    • 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

Definitions

  • the present invention relates to an optical communication system, an optical transmission device, an optical reception device, an optical communication method, an optical transmission method, a phase rotation setting device, and an optical reception method using an optical signal.
  • optical phase modulation method using a digital signal processing technology and a polarization multiplexing / demultiplexing technology.
  • a technique combining an optical phase modulation system and a polarization multiplexing / demultiplexing technique, so-called optical digital coherent communication system, has been attracting attention in recent years because it can realize high speed in long-distance optical communication.
  • Patent Documents 1 and 2 there are technologies described in Patent Documents 1 and 2 as technologies related to optical communication.
  • Patent Document 1 performs compensation for waveform distortion occurring in a transmission path by sharing between a transmitting station and a receiving station. Details are as follows. First, an optical signal transmitting station performs distortion compensation on a transmission signal based on a transmission distortion compensation coefficient. The optical signal receiving station performs distortion compensation on the received signal based on the received distortion compensation coefficient.
  • Patent Document 2 sets the dispersion amount of dispersion compensation on the transmission side so that the number of bit errors detected on the reception side is minimized.
  • the optical signal undergoes phase fluctuation proportional to the square of the amplitude due to the nonlinear optical effect during transmission of the optical fiber. For this reason, the transmission characteristic of the optical signal is deteriorated.
  • An object of the present invention is to provide an optical communication system, an optical transmission device, an optical reception device, an optical communication method, an optical transmission method, a phase rotation setting device, and an optical reception method that suppress degradation of an optical signal during transmission of an optical fiber. Is to provide.
  • an optical transmission device that transmits an optical signal for transmission;
  • An optical receiver for receiving the optical signal for transmission;
  • the optical transmitter is Optical signal generating means for generating the transmission optical signal by modulating a carrier wave;
  • Filter processing means for performing a process of adding a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave to the transmission optical signal;
  • Have The optical receiver is a compensation unit that performs processing for compensating the phase rotation added to the optical signal for transmission by the filter processing unit with respect to a signal generated based on the optical signal for transmission;
  • An optical communication system is provided.
  • an optical transmission device that transmits an optical signal for transmission;
  • An optical receiver for receiving the optical signal for transmission;
  • the optical transmitter is Optical signal generating means for generating the transmission optical signal by modulating a carrier wave;
  • the integrated value of the peak value of the light intensity in the extending direction of the optical fiber or the extending direction of the optical fiber of PAPR (Peak to Average Power Ratio) of the light intensity Filter processing means for applying phase rotation to the transmission optical signal so that the integrated value at Have
  • the optical receiver includes a compensation unit that performs a process of compensating the phase rotation added to the transmission optical signal by the filter processing unit with respect to a signal generated based on the transmission optical signal.
  • an optical signal generating means for generating a transmission optical signal by modulating a carrier wave
  • Filter processing means for performing a process of adding a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave to the transmission optical signal;
  • An optical transmission device is provided.
  • the present invention comprising a compensation means for performing a filtering process on a signal generated based on a transmission optical signal transmitted from an optical transmission device,
  • the transmission optical signal is generated by modulating a carrier wave, and for each frequency of the carrier wave, a phase rotation having a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant is applied.
  • the compensation means is provided with an optical receiver that performs processing for compensating for the phase rotation.
  • an optical transmission device that transmits an optical signal for transmission;
  • An optical receiver for receiving the optical signal for transmission; Used with an optical communication system comprising:
  • the optical transmitter is Optical signal generating means for generating the transmission optical signal by modulating a carrier wave;
  • Filter processing means for performing a process of adding a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave to the transmission optical signal;
  • Have The optical receiver includes a compensation unit that compensates for the phase rotation added to the optical signal for transmission by the filter processing unit in a signal generated based on the optical signal for transmission;
  • a phase rotation setting device is provided that transmits information indicating the magnitude of the phase rotation to the filter processing means and the compensation means.
  • the optical transmission device generates a transmission optical signal by modulating a carrier wave, and the transmission optical signal is divided into the square of the deviation of the carrier wave at the frequency for each frequency of the carrier wave. Add a phase rotation with the same constant multiplied, An optical communication method is provided in which an optical receiver compensates the phase rotation for a signal generated based on the transmission optical signal.
  • an optical signal for transmission is generated by modulating a carrier wave, and the same constant as the square of the deviation of the carrier wave at the frequency for each frequency of the carrier wave with respect to the optical signal for transmission.
  • An optical transmission method for transmitting the transmission optical signal after performing the process of applying the phase rotation of the magnitude multiplied by the above is provided.
  • a process that is generated by modulating a carrier wave and adds a phase rotation having a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave.
  • an optical reception method for receiving a transmission optical signal subjected to the above and performing a process for compensating the phase rotation on a signal generated based on the transmission optical signal.
  • FIG. 1 is a diagram illustrating a configuration of an optical communication system according to the first embodiment.
  • This optical communication system includes an optical transmitter 10 and an optical receiver 20.
  • the optical transmitter 10 transmits an optical signal for transmission.
  • the optical receiver 20 receives a transmission optical signal.
  • the optical transmission device 10 includes an optical signal generation unit 110 and a filter processing unit 120.
  • the optical signal generation unit 110 generates a transmission optical signal by modulating a carrier wave based on a signal to be transmitted (transmission signal).
  • the filter processing unit 120 applies a phase rotation to the transmission signal for each frequency of the carrier wave with a magnitude obtained by multiplying the square of the carrier wave deviation at that frequency by the same constant (ie, a magnitude proportional to the deviation). Process.
  • the filter processing unit 120 applies phase rotation to the transmission optical signal by processing the transmission signal.
  • the filter processing unit 120 does not directly hold the phase rotation amount as a parameter, but may hold a parameter that affects the phase rotation amount.
  • the optical receiver 20 has a compensation unit 210.
  • the compensation unit 210 performs processing for compensating for the above-described phase rotation on the signal generated from the transmission optical signal. Note that the compensation unit 210 does not directly hold the phase rotation amount as a parameter, but may hold a parameter that affects the phase rotation amount.
  • the nonlinear optical effect in the optical fiber is proportional to the intensity of the transmission optical signal.
  • the intensity of the transmission optical signal is simply lowered, the SN (Signal to Noise) ratio of the transmission optical signal is lowered.
  • a process for applying a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave is performed on the transmission signal. Applying such phase rotation imparts chromatic dispersion to the carrier wave.
  • chromatic dispersion is given to the carrier wave, the peak value of the light intensity of the optical signal at each point of the optical fiber transmission line changes.
  • the integrated value of the peak value of the light intensity in the extending direction of the optical fiber, or the light It is possible to reduce the integrated value of PAPR (Peak-to-Average-Power-Ratio) in the drawing direction of the strong optical fiber.
  • PAPR Peak-to-Average-Power-Ratio
  • the integrated value can be lowered. Therefore, the nonlinear optical effect in the optical fiber can be suppressed without reducing the average intensity of the transmission optical signal. Therefore, it is possible to suppress degradation of the optical signal during transmission of the optical fiber.
  • the above integrated value can be obtained, for example, by providing measurement points at predetermined intervals in the drawing direction of the optical fiber and integrating the measurement results (or simulation values).
  • the filter processing unit 120 if the constant used by the filter processing unit 120 is set to an appropriate value, the integrated value described above can be minimized. In this case, the above-described effect becomes the largest.
  • FIG. 2 is a diagram illustrating a configuration of the optical transmission device 10 according to the second embodiment.
  • FIG. 3 is a diagram illustrating a configuration of the optical receiving device 20 according to the present embodiment.
  • the optical communication system according to the present embodiment is the same as the optical communication system according to the first embodiment except for the detailed configurations of the optical transmission device 10 and the optical reception device 20.
  • the optical communication system according to the present embodiment transmits and receives signals using an optical digital coherent method.
  • the optical transmission device 10 includes optical modulation units 112 and 114, filter processing units 122 and 124, drive signal generation units 132 and 134, DA (Digital-to-Analog) conversion units 142 and 144, a ⁇ / 2 phase shifter 150, and laser oscillation. Part 152 is provided.
  • the optical modulation units 112 and 114 constitute an optical signal generation unit 110
  • the filter processing units 122 and 124 constitute a filter processing unit 120.
  • the laser oscillation unit 152 oscillates a laser beam that becomes a carrier wave.
  • the laser beam generated by the laser oscillation unit 152 is branched into two and input to the light modulation unit 112 and the light modulation unit 114.
  • the drive signal generators 132 and 134 generate drive signals based on signals to be transmitted.
  • the filter processor 122 performs a filtering process on the drive signal generated by the drive signal generator 132.
  • the filter processing unit 124 performs a filtering process on the drive signal generated by the drive signal generation unit 134.
  • the filtering process performed by the filter processing unit 122 adds a phase rotation of a magnitude obtained by multiplying the square of the carrier wave deviation at the frequency by the same constant to the optical signal generated by the optical modulation unit 112 for each frequency. It is.
  • the filtering process performed by the filter processing unit 124 applies, to the optical signal generated by the optical modulation unit 114, a phase rotation having a magnitude obtained by multiplying the square of the carrier wave deviation at the frequency by the same constant for each frequency. It is.
  • the magnitude of the phase rotation applied to the optical signal by the filter processing unit 122 and the filter processing unit 124 may be equal to each other or may be different from each other.
  • the filter processing units 122 and 124 are, for example, FIR (Finite Impulse Response) filters.
  • the filter processing units 122 and 124 may perform the above-described processing using a lookup table.
  • the light modulator 112 modulates the laser beam according to the drive signal processed by the filter processor 122 to generate an optical signal.
  • the light modulator 114 modulates the laser light according to the drive signal processed by the filter processor 124 to generate an optical signal.
  • the ⁇ / 2 phase shifter 150 changes the transfer of the optical signal generated by the light modulation unit 114 by ⁇ / 2. Thereafter, the optical signal generated by the optical modulation unit 112 and the optical signal generated by the optical modulation unit 114 are combined into an optical signal for transmission. This transmission optical signal is transmitted to the optical receiver 20 via the optical fiber 300.
  • the optical communication system further includes an optical fiber information management unit 310 and a phase rotation setting device 320.
  • the optical fiber information management unit 310 stores the peak value of the intensity of the transmission optical signal in the extending direction of the optical fiber 300 or the integrated value of PAPR. These integrated values may be calculated by the optical fiber information management unit 310 or may be input to the optical fiber information management unit 310 from the outside.
  • the phase rotation setting device 320 sets the phase rotation amount in the filter processing units 122 and 124 or the chromatic dispersion amount to be added by the filter processing units 122 and 124 based on the information stored in the optical fiber information management unit 310. The set value is transmitted to the filter processing unit 122 and the filter processing unit 124.
  • phase rotation setting device 320 changes the values transmitted to the filter processing unit 122 and the filter processing unit 124 while observing the change of the integrated value stored in the optical fiber information management unit 310, and thereby the filter processing unit 122 and An optimum value to be transmitted to the filter processing unit 124 may be determined.
  • the optical receiver 20 includes a compensation unit 210, a local light generation unit 220, a 90 ° optical hybrid 222, an optical detector 224, an AD (Analog-to-Digital) converter 226, a chromatic dispersion compensation unit 228, a polarization separation unit 230, and a deviation compensation unit 232. And a symbol identification unit 234.
  • a compensation unit 210 a local light generation unit 220, a 90 ° optical hybrid 222, an optical detector 224, an AD (Analog-to-Digital) converter 226, a chromatic dispersion compensation unit 228, a polarization separation unit 230, and a deviation compensation unit 232.
  • AD Analog-to-Digital
  • the local light generator 220 oscillates local light. Local light has substantially the same frequency as the carrier wave.
  • the 90 ° optical hybrid 222 receives a transmission optical signal and local light from the local light generator 211.
  • the 90 ° optical hybrid 222 generates four optical signals by causing the optical signal and local light to interfere with each other.
  • the optical detector 224 photoelectrically converts the four optical signals generated by the 90 ° optical hybrid 222 to generate four analog signals.
  • the AD converter 226 converts the four analog signals generated by the optical detector 224 into digital signals, respectively.
  • the compensation unit 210 performs compensation processing on each of the four digital signals generated by the AD converter 226 based on the values sent from the phase rotation setting device 320. This compensation processing adds optical phase rotation, which has the same absolute value and opposite sign, to the optical phase rotation given to the optical signal for transmission by the filter processing unit 120 of the optical transmission device 10.
  • the chromatic dispersion compensation unit 228 performs processing for compensating the chromatic dispersion added to the transmission optical signal in the optical fiber 300 on the four digital signals processed by the compensation unit 210.
  • the polarization separation unit 230 generates a signal indicating the transmitted information using the four digital signals.
  • the deviation compensation unit 232 compensates for a frequency deviation and an optical phase deviation between the transmission optical signal and the local light. Thereby, the noise of the signal due to the rotation of the optical phase is compensated.
  • the symbol identification unit 223 performs symbol determination using the signal after compensation by the deviation compensation unit 232. Thereby, the transmitted signal is demodulated.
  • FIG. 4 is a diagram showing the relationship between the transmission distance of the optical signal and the peak value of the intensity of the optical signal.
  • a dotted line indicates a simulation result when the filter processing unit 120 and the compensation unit 210 are not operated
  • a solid line indicates a simulation when the filter processing unit 120 and the compensation unit 210 are operated. Results are shown. From this figure, it can be seen that the peak value of the intensity of the optical signal changes by operating the filter processing unit 120 and the compensation unit 210.
  • FIG. 5 is a diagram illustrating a relationship between the magnitude of the phase rotation (parameter value) applied by the filter processing unit 120 and the compensation unit 210 and the integrated amount of the peak value of the light intensity of the transmission signal in the extending direction of the optical fiber 300. is there. From this figure, when the parameter is set to an appropriate value, the integrated value of the peak value of the intensity of the optical signal can be reduced as compared with the case where the parameter is 0, that is, when the filter processing unit 120 and the compensation unit 210 are not operated. I understand that.
  • FIG. 6 is a diagram illustrating the relationship between the magnitude of the phase rotation (parameter value) applied by the filter processing unit 120 and the compensation unit 210 and the Q value of the signal received by the optical receiver 20. From this figure, it can be seen that the Q value increases when the parameter is set to an appropriate value. Comparing FIG. 5 and FIG. 6, it can be seen that the Q value increases when the integrated value of the peak value of the intensity of the optical signal decreases.
  • the phase rotation setting device 320 recognizes the peak value of the intensity of the optical signal for transmission stored in the optical fiber information management unit 310 or the integrated value of the PAPR, and sets the parameters of the filter processing unit 120 and the compensation unit 210. Can be changed. For this reason, the parameters of the filter processing unit 120 and the compensation unit 210 can be easily set by using the phase rotation setting device 320.
  • the administrator of the optical communication system may directly set the parameters of the filter processing units 122 and 124 and the compensation unit 210 without providing the phase rotation setting device 320.
  • FIG. 7 is a diagram illustrating a configuration of the optical transmission device 10 according to the third embodiment
  • FIG. 8 is a diagram illustrating a configuration of the optical reception device 20 according to the third embodiment.
  • the optical transmitter 10 and the optical receiver 20 shown in this figure transmit and receive optical signals using the polarization multiplexing method.
  • the basic configuration of the optical transmitter 10 and the optical receiver 20 is the same as that of the second embodiment.
  • the optical transmission device 10 includes two sets of a drive signal generation unit 132, a filter processing unit 122, and a DA conversion unit 142.
  • the first set of drive signal generation unit 132, filter processing unit 122, and DA conversion unit 142 generate drive signals corresponding to the I phase.
  • the second set of drive signal generation unit 132, filter processing unit 122, and DA conversion unit 142 generate drive signals corresponding to the Q phase.
  • the drive signals output from the two DA converters 142 are both input to the light modulator 112.
  • the light modulation unit 112 is an optical I / Q modulator.
  • the optical transmission device 10 also includes two sets of the drive signal generation unit 134, the filter processing unit 124, and the DA conversion unit 144.
  • the first set of drive signal generation unit 134, filter processing unit 124, and DA conversion unit 144 generate drive signals corresponding to the I phase.
  • the second set of drive signal generator 134, filter processor 124, and DA converter 144 generates a drive signal corresponding to the Q phase.
  • the drive signals output from the two DA converters 144 are both input to the light modulator 114.
  • the light modulator 114 is also an optical I / Q modulator.
  • Both the two filter processing units 122 and the two filter processing units 124 perform a process of adding a rotation phase to the drive signal according to the information transmitted from the phase rotation setting device 320.
  • the optical transmission device 10 has a multiplexing unit 160.
  • the multiplexing unit 160 is in a state in which the optical signal (first optical signal) generated by the optical modulation unit 112 and the optical signal (second optical signal) generated by the optical modulation unit 114 are orthogonal to each other.
  • the optical signal for transmission is generated by multiplexing in the above.
  • the optical receiver 20 has the same configuration as 30 according to the second embodiment except for the following points.
  • the 90 ° optical hybrid 222 generates an optical signal (I x ) by causing an optical signal and local light to interfere with each other with a phase difference of 0, and causes the optical signal and local light to interfere with each other with a phase difference of ⁇ / 2.
  • a signal (Q x ) is generated.
  • the 90 ° optical hybrid 222 generates an optical signal (I y ) by causing the optical signal and local light to interfere with each other with a phase difference of 0, and causes the optical signal and local light to interfere with each other with a phase difference of ⁇ / 2. (Q y ) is generated.
  • E xin (t) indicates a signal transmitted from the light modulator 112
  • E yin (t) indicates a signal transmitted from the light modulator 114.
  • the first set of deviation compensation unit 232 and symbol identification unit 234 processes E xin (t).
  • the second set of deviation compensation unit 232 and symbol identification unit 234 processes E yin (t).
  • the optical fiber information management unit 310 includes the intensity peak value or PAPR of the polarization component corresponding to the optical signal generated by the optical modulation unit 112 in the extending direction of the optical fiber 300 among the transmission optical signals. And the intensity peak value or PAPR integrated value of the polarization component corresponding to the optical signal generated by the optical modulation unit 114 in the extending direction of the optical fiber 300 are stored. Then, the phase rotation setting device 320 controls the filter processing units 122 and 124 based on a value obtained by adding the integrated values of these two peak values (or PAPR). Here, the phase rotation setting device 320 may add these two values after multiplying the two integrated values by different coefficients. The phase rotation setting device 320 preferably controls the filter processing units 122 and 124 so that a value obtained by adding the two integrated values is minimized.
  • the same effect as that of the second embodiment can be obtained also in the polarization multiplexing optical communication system.
  • FIG. 9 is a diagram illustrating a configuration of an optical receiver 20 used in the optical communication system according to the fourth embodiment.
  • the optical receiver 20 according to the present embodiment has the same configuration as that of the optical receiver 20 according to the second embodiment, except that the chromatic dispersion compensation unit 228 also functions as the compensation unit 210.
  • the chromatic dispersion compensator 228 may also function as the compensator 210.
  • the magnitude of the phase rotation (that is, the magnitude of chromatic dispersion) applied by the filter processing sections 122 and 124 is equal to or less than the magnitude of chromatic dispersion that can be compensated by the chromatic dispersion compensating section 228.
  • the same effect as that of the second embodiment can be obtained. Further, since it is not necessary to provide the compensation unit 210, the structure of the optical receiver 20 can be simplified.
  • FIG. 10 is a diagram illustrating a configuration of an optical receiver 20 used in the optical communication system according to the fifth embodiment.
  • the optical receiving apparatus 20 according to the present embodiment has the same configuration as the optical receiving apparatus 20 according to the second embodiment, except that an optical dispersion compensation unit 236 is provided instead of the compensation unit 210.
  • the optical dispersion compensation unit 236 is, for example, a dispersion compensation fiber, and is a compensator that optically compensates for dispersion of light. Note that, also in the optical receiving device 20 according to the third embodiment, an optical dispersion compensation unit 236 may be provided instead of the compensation unit 210.
  • the same effect as that of the second embodiment can be obtained.
  • the phase rotation that is, chromatic dispersion
  • the digital processing circuit can be simplified.
  • FIG. 11 is a diagram illustrating a configuration of an optical communication system according to the sixth embodiment.
  • the optical communication system has a plurality of optical receivers 20.
  • the filter process part 120 changes the magnitude
  • the details of the configurations of the optical transmitter 10 and the optical receiver 20 are the same as those in any of the first to fifth embodiments.
  • the filter processing unit 120 varies the magnitude of the phase rotation depending on the optical receiver 20 that is the transmission destination, and therefore, even when transmitting the optical signal for transmission to any of the optical receivers 20 The same effects as those of the above-described embodiment can be obtained.

Landscapes

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

Abstract

An optical signal generation unit (110) generates optical signals for transmission by modulating carrier waves on the basis of signals to be transmitted. A filter processing unit (120) adds to the signal for transmission, for each carrier wave frequency, a phase rotation of a size that is the square of the carrier wave deviation for the relevant frequency multiplied by the same constant (i.e., a size proportional to the deviation). An optical reception device (20) has a compensation unit (210). The compensation unit (210) compensates said phase rotation, for the signal generated from the optical signal for transmission.

Description

光通信システム、光送信装置、光受信装置、光通信方法、光送信方法、位相回転設定装置、及び光受信方法Optical communication system, optical transmission device, optical reception device, optical communication method, optical transmission method, phase rotation setting device, and optical reception method
　本発明は、光信号を用いる光通信システム、光送信装置、光受信装置、光通信方法、光送信方法、位相回転設定装置、及び光受信方法に関する。 The present invention relates to an optical communication system, an optical transmission device, an optical reception device, an optical communication method, an optical transmission method, a phase rotation setting device, and an optical reception method using an optical signal.
　インターネットの普及により、基幹ネットワークのトラフィック量が急増している。これに対応するために、長距離の光通信における高速化が強く望まれている。光通信の高速化に対応する技術として、デジタル信号処理技術を活用した光位相変調方式、及び偏光多重分離技術がある。光位相変調方式と偏光多重分離技術を組み合わせた技術、所謂光デジタルコヒーレント通信方式は、長距離の光通信における高速化が実現できるため、近年注目されている。 The traffic volume of the backbone network is increasing rapidly due to the spread of the Internet. In order to cope with this, high speed in long-distance optical communication is strongly desired. As technologies corresponding to high-speed optical communication, there are an optical phase modulation method using a digital signal processing technology and a polarization multiplexing / demultiplexing technology. A technique combining an optical phase modulation system and a polarization multiplexing / demultiplexing technique, so-called optical digital coherent communication system, has been attracting attention in recent years because it can realize high speed in long-distance optical communication.
　一方、光通信に関する技術としては、例えば特許文献１，２に記載の技術がある。 On the other hand, for example, there are technologies described in Patent Documents 1 and 2 as technologies related to optical communication.
　特許文献１に記載の技術は、伝送路内で生じる波形歪の補償を、送信局と受信局とで分担して行うものである。詳細は、以下の通りである。まず、光信号の送信局は、送信歪補償係数に基づいて、送信信号に対して歪補償を行う。また光信号の受信局は、受信歪補償係数に基づいて、受信信号に対して歪補償を行う。 The technique described in Patent Document 1 performs compensation for waveform distortion occurring in a transmission path by sharing between a transmitting station and a receiving station. Details are as follows. First, an optical signal transmitting station performs distortion compensation on a transmission signal based on a transmission distortion compensation coefficient. The optical signal receiving station performs distortion compensation on the received signal based on the received distortion compensation coefficient.
　特許文献２に記載の技術は、受信側で検出されるビット誤り数が最小になるように、送信側での分散補償の分散量を設定するものである。 The technique described in Patent Document 2 sets the dispersion amount of dispersion compensation on the transmission side so that the number of bit errors detected on the reception side is minimized.
特開２００９－２３９５５５号公報JP 2009-239555 A 特開２０１０－０３４８３０号公報JP 2010-034830 A
　光信号は、光ファイバの伝送中に、非線形光学効果により、振幅の二乗に比例する位相変動を受ける。このため、光信号の伝送特性が劣化してしまう。 The optical signal undergoes phase fluctuation proportional to the square of the amplitude due to the nonlinear optical effect during transmission of the optical fiber. For this reason, the transmission characteristic of the optical signal is deteriorated.
　本発明の目的は、光ファイバの伝送中に光信号が劣化することを抑制する光通信システム、光送信装置、光受信装置、光通信方法、光送信方法、位相回転設定装置、及び光受信方法を提供することにある。 An object of the present invention is to provide an optical communication system, an optical transmission device, an optical reception device, an optical communication method, an optical transmission method, a phase rotation setting device, and an optical reception method that suppress degradation of an optical signal during transmission of an optical fiber. Is to provide.
　本発明によれば、送信用光信号を送信する光送信装置と、
　前記送信用光信号を受信する光受信装置と、
を備え、
　前記光送信装置は、
　　搬送波を変調することにより前記送信用光信号を生成する光信号生成手段と、
　　前記送信用光信号に対して、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理を行うフィルタ処理手段と、
を有し、
　前記光受信装置は、前記送信用光信号に基づいて生成された信号に対して、前記フィルタ処理手段が前記送信用光信号に加えた前記位相回転を補償する処理を行う補償手段と、
を有する光通信システムが提供される。 According to the present invention, an optical transmission device that transmits an optical signal for transmission;
An optical receiver for receiving the optical signal for transmission;
With
The optical transmitter is
Optical signal generating means for generating the transmission optical signal by modulating a carrier wave;
Filter processing means for performing a process of adding a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave to the transmission optical signal;
Have
The optical receiver is a compensation unit that performs processing for compensating the phase rotation added to the optical signal for transmission by the filter processing unit with respect to a signal generated based on the optical signal for transmission;
An optical communication system is provided.
　本発明によれば、送信用光信号を送信する光送信装置と、
　前記送信用光信号を受信する光受信装置と、
を備え、
　前記光送信装置は、
　　搬送波を変調することにより前記送信用光信号を生成する光信号生成手段と、
　　前記光送信装置と前記光受信装置の間の光ファイバにおいて、光強度のピーク値の前記光ファイバの延伸方向における積算値又は光強度のＰＡＰＲ（Peak to Average Power Ratio）の前記光ファイバの延伸方向における積算値が最小となるように、前記送信用光信号に位相回転を加えるフィルタ処理手段と、
を有し、
　前記光受信装置は、前記送信用光信号に基づいて生成された信号に対して、前記フィルタ処理手段が前記送信用光信号に加えた前記位相回転を補償する処理を行う補償手段を有する光通信システムが提供される。 According to the present invention, an optical transmission device that transmits an optical signal for transmission;
An optical receiver for receiving the optical signal for transmission;
With
The optical transmitter is
Optical signal generating means for generating the transmission optical signal by modulating a carrier wave;
In the optical fiber between the optical transmitter and the optical receiver, the integrated value of the peak value of the light intensity in the extending direction of the optical fiber or the extending direction of the optical fiber of PAPR (Peak to Average Power Ratio) of the light intensity Filter processing means for applying phase rotation to the transmission optical signal so that the integrated value at
Have
The optical receiver includes a compensation unit that performs a process of compensating the phase rotation added to the transmission optical signal by the filter processing unit with respect to a signal generated based on the transmission optical signal. A system is provided.
　本発明によれば、搬送波を変調することにより送信用光信号を生成する光信号生成手段と、
　前記送信用光信号に対して、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理を行うフィルタ処理手段と、
を備える光送信装置が提供される。 According to the present invention, an optical signal generating means for generating a transmission optical signal by modulating a carrier wave;
Filter processing means for performing a process of adding a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave to the transmission optical signal;
An optical transmission device is provided.
　本発明によれば、光送信装置から送信された送信用光信号に基づいて生成された信号にフィルタ処理を行う補償手段を備え、
　前記送信用光信号は、搬送波を変調することにより生成されており、かつ、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理が加えられており、
　前記補償手段は、前記位相回転を補償する処理を行う光受信装置が提供される。 According to the present invention, comprising a compensation means for performing a filtering process on a signal generated based on a transmission optical signal transmitted from an optical transmission device,
The transmission optical signal is generated by modulating a carrier wave, and for each frequency of the carrier wave, a phase rotation having a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant is applied. Processing has been added,
The compensation means is provided with an optical receiver that performs processing for compensating for the phase rotation.
　本発明によれば、送信用光信号を送信する光送信装置と、
　前記送信用光信号を受信する光受信装置と、
を備える光通信システムと共に使用され、
　　前記光送信装置は、
　　搬送波を変調することにより前記送信用光信号を生成する光信号生成手段と、
　　前記送信用光信号に対して、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理を行うフィルタ処理手段と、
を有し、
　前記光受信装置は、前記送信用光信号に基づいて生成された信号に、前記フィルタ処理手段が前記送信用光信号に加えた前記位相回転を補償する補償手段を有し、
　前記フィルタ処理手段及び前記補償手段に、前記位相回転の大きさを示す情報を送信する位相回転設定装置が提供される。 According to the present invention, an optical transmission device that transmits an optical signal for transmission;
An optical receiver for receiving the optical signal for transmission;
Used with an optical communication system comprising:
The optical transmitter is
Optical signal generating means for generating the transmission optical signal by modulating a carrier wave;
Filter processing means for performing a process of adding a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave to the transmission optical signal;
Have
The optical receiver includes a compensation unit that compensates for the phase rotation added to the optical signal for transmission by the filter processing unit in a signal generated based on the optical signal for transmission;
A phase rotation setting device is provided that transmits information indicating the magnitude of the phase rotation to the filter processing means and the compensation means.
　本発明によれば、光送信装置が、搬送波を変調することにより送信用光信号を生成し、かつ前記送信用光信号に、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加え、
　光受信装置が、前記送信用光信号に基づいて生成された信号に、前記位相回転を補償する光通信方法が提供される。 According to the present invention, the optical transmission device generates a transmission optical signal by modulating a carrier wave, and the transmission optical signal is divided into the square of the deviation of the carrier wave at the frequency for each frequency of the carrier wave. Add a phase rotation with the same constant multiplied,
An optical communication method is provided in which an optical receiver compensates the phase rotation for a signal generated based on the transmission optical signal.
　本発明によれば、搬送波を変調することにより送信用光信号を生成し、かつ前記送信用光信号に対して、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理を行ってから、前記送信用光信号を送信する光送信方法が提供される。 According to the present invention, an optical signal for transmission is generated by modulating a carrier wave, and the same constant as the square of the deviation of the carrier wave at the frequency for each frequency of the carrier wave with respect to the optical signal for transmission. An optical transmission method for transmitting the transmission optical signal after performing the process of applying the phase rotation of the magnitude multiplied by the above is provided.
　本発明によれば、搬送波を変調することにより生成されており、かつ、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理が行われた送信用光信号を受信し、前記送信用光信号に基づいて生成された信号に対して、前記位相回転を補償する処理を行う光受信方法が提供される。 According to the present invention, a process that is generated by modulating a carrier wave and adds a phase rotation having a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave. There is provided an optical reception method for receiving a transmission optical signal subjected to the above and performing a process for compensating the phase rotation on a signal generated based on the transmission optical signal.
　本発明によれば、光ファイバの伝送中に光信号が劣化することを抑制できる。 According to the present invention, it is possible to suppress degradation of an optical signal during transmission of an optical fiber.
　上述した目的、およびその他の目的、特徴および利点は、以下に述べる好適な実施の形態、およびそれに付随する以下の図面によってさらに明らかになる。 The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.
第１の実施形態に係る光通信システムの構成を示す図である。It is a figure which shows the structure of the optical communication system which concerns on 1st Embodiment. 第２の実施形態に係る光送信装置の構成を示す図である。It is a figure which shows the structure of the optical transmitter which concerns on 2nd Embodiment. 第２の実施形態に係る光受信装置の構成を示す図である。It is a figure which shows the structure of the optical receiver which concerns on 2nd Embodiment. 光信号の伝送距離と、光信号の強度のピーク値との関係を示す図である。It is a figure which shows the relationship between the transmission distance of an optical signal, and the peak value of the intensity | strength of an optical signal. フィルタ処理部及び補償部で加える位相回転（パラメータ値）の大きさと、光ファイバの延伸方向における送信用信号の光強度のピーク値の積算量との関係を示す図である。It is a figure which shows the relationship between the magnitude | size of the phase rotation (parameter value) added by a filter process part and a compensation part, and the integrated amount of the peak value of the light intensity of the signal for transmission in the extending | stretching direction of an optical fiber. フィルタ処理部及び補償部で加える位相回転（パラメータ値）の大きさと、光受信装置で受信した信号のＱ値との関係を示す図である。It is a figure which shows the relationship between the magnitude | size of the phase rotation (parameter value) added by a filter process part and a compensation part, and Q value of the signal received with the optical receiver. 第３の実施形態に係る光送信装置の構成を示す図である。It is a figure which shows the structure of the optical transmitter which concerns on 3rd Embodiment. 第３の実施形態に係る光受信装置の構成を示す図である。It is a figure which shows the structure of the optical receiver which concerns on 3rd Embodiment. 第４の実施形態に係る光受信装置の構成を示す図である。It is a figure which shows the structure of the optical receiver which concerns on 4th Embodiment. 第５の実施形態に係る光受信装置の構成を示す図である。It is a figure which shows the structure of the optical receiver which concerns on 5th Embodiment. 第６の実施形態に係る光通信システムの構成を示す図である。It is a figure which shows the structure of the optical communication system which concerns on 6th Embodiment.
　以下、本発明の実施の形態について、図面を用いて説明する。尚、すべての図面において、同様な構成要素には同様の符号を付し、適宜説明を省略する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.
（第１の実施形態）
　図１は、第１の実施形態に係る光通信システムの構成を示す図である。この光通信システムは、光送信装置１０及び光受信装置２０を有している。光送信装置１０は、送信用光信号を送信する。光受信装置２０は、送信用光信号を受信する。 (First embodiment)
FIG. 1 is a diagram illustrating a configuration of an optical communication system according to the first embodiment. This optical communication system includes an optical transmitter 10 and an optical receiver 20. The optical transmitter 10 transmits an optical signal for transmission. The optical receiver 20 receives a transmission optical signal.
　詳細には、光送信装置１０は、光信号生成部１１０及びフィルタ処理部１２０を有している。光信号生成部１１０は、搬送波を、送信すべき信号（送信信号）に基づいて変調することにより、送信用光信号を生成する。フィルタ処理部１２０は、送信用信号に対して、搬送波の周波数別に、当該周波数における搬送波の偏差の２乗に同一の定数を乗じた大きさ（すなわち偏差に比例した大きさ）の位相回転を加える処理を行う。本図に示す例では、フィルタ処理部１２０は、送信信号を処理することにより、送信用光信号に位相回転を加える。フィルタ処理部１２０は、位相回転量を直接パラメータとして保持しているのではなく、位相回転量に影響を与えるパラメータを保持していてもよい。 Specifically, the optical transmission device 10 includes an optical signal generation unit 110 and a filter processing unit 120. The optical signal generation unit 110 generates a transmission optical signal by modulating a carrier wave based on a signal to be transmitted (transmission signal). The filter processing unit 120 applies a phase rotation to the transmission signal for each frequency of the carrier wave with a magnitude obtained by multiplying the square of the carrier wave deviation at that frequency by the same constant (ie, a magnitude proportional to the deviation). Process. In the example shown in the figure, the filter processing unit 120 applies phase rotation to the transmission optical signal by processing the transmission signal. The filter processing unit 120 does not directly hold the phase rotation amount as a parameter, but may hold a parameter that affects the phase rotation amount.
　光受信装置２０は、補償部２１０を有している。補償部２１０は、送信用光信号から生成された信号に対して、上記した位相回転を補償する処理を行う。なお、補償部２１０は、位相回転量を直接パラメータとして保持しているのではなく、位相回転量に影響を与えるパラメータを保持していてもよい。 The optical receiver 20 has a compensation unit 210. The compensation unit 210 performs processing for compensating for the above-described phase rotation on the signal generated from the transmission optical signal. Note that the compensation unit 210 does not directly hold the phase rotation amount as a parameter, but may hold a parameter that affects the phase rotation amount.
　光ファイバにおける非線形光学効果は、送信用光信号の強度に比例する。しかし、単純に送信用光信号の強度を低くすると、送信用光信号のＳＮ（Signal to Noise）比が低下してしまう。これに対して本実施形態では、送信用信号に対して、搬送波の周波数別に、当該周波数における搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理を行う。このような位相回転を加えることは、搬送波に波長分散を付与することになる。搬送波に波長分散を付与した場合、光ファイバ伝送路の各点における光信号の光強度のピーク値が変化するため、その結果、光強度の光ファイバの延伸方向におけるピーク値の積算値、又は光強度の光ファイバの延伸方向におけるＰＡＰＲ（Peak to Average Power Ratio）の積算値を小さくすることが可能となる。この場合、光送信装置１０と光受信装置２０を結ぶ光ファイバの延伸方向について、光の振幅の２乗値を積算した場合、その積算値を低くすることができる。このため、送信用光信号の平均強度を低下させなくても、光ファイバにおける非線形光学効果を抑制することができる。従って、光ファイバの伝送中に光信号が劣化することを抑制できる。 The nonlinear optical effect in the optical fiber is proportional to the intensity of the transmission optical signal. However, if the intensity of the transmission optical signal is simply lowered, the SN (Signal to Noise) ratio of the transmission optical signal is lowered. On the other hand, in the present embodiment, a process for applying a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave is performed on the transmission signal. Applying such phase rotation imparts chromatic dispersion to the carrier wave. When chromatic dispersion is given to the carrier wave, the peak value of the light intensity of the optical signal at each point of the optical fiber transmission line changes. As a result, the integrated value of the peak value of the light intensity in the extending direction of the optical fiber, or the light It is possible to reduce the integrated value of PAPR (Peak-to-Average-Power-Ratio) in the drawing direction of the strong optical fiber. In this case, when the square value of the amplitude of the light is integrated in the extending direction of the optical fiber connecting the optical transmitter 10 and the optical receiver 20, the integrated value can be lowered. Therefore, the nonlinear optical effect in the optical fiber can be suppressed without reducing the average intensity of the transmission optical signal. Therefore, it is possible to suppress degradation of the optical signal during transmission of the optical fiber.
　なお、上記した積算値は、例えば光ファイバの延伸方向において所定間隔ごとに測定点を設け、その測定結果（又はシミュレーション値）を積算することにより、得ることができる。 The above integrated value can be obtained, for example, by providing measurement points at predetermined intervals in the drawing direction of the optical fiber and integrating the measurement results (or simulation values).
　ここで、フィルタ処理部１２０が用いる定数を適切な値に設定すると、上記した積算値を最小にすることができる。この場合、上記した効果が最も大きくなる。 Here, if the constant used by the filter processing unit 120 is set to an appropriate value, the integrated value described above can be minimized. In this case, the above-described effect becomes the largest.
（第２の実施形態）
　図２は、第２の実施形態に係る光送信装置１０の構成を示す図である。図３は、本実施形態に係る光受信装置２０の構成を示す図である。本実施形態に係る光通信システムは、光送信装置１０及び光受信装置２０の詳細な構成を除いて、第１の実施形態に係る光通信システムと同様である。本実施形態に係る光通信システムは、光デジタルコヒーレント方式で信号を送受信するものである。 (Second Embodiment)
FIG. 2 is a diagram illustrating a configuration of the optical transmission device 10 according to the second embodiment. FIG. 3 is a diagram illustrating a configuration of the optical receiving device 20 according to the present embodiment. The optical communication system according to the present embodiment is the same as the optical communication system according to the first embodiment except for the detailed configurations of the optical transmission device 10 and the optical reception device 20. The optical communication system according to the present embodiment transmits and receives signals using an optical digital coherent method.
　まず、図２を用いて光送信装置１０の構成を説明する。光送信装置１０は、光変調部１１２，１１４、フィルタ処理部１２２，１２４、駆動信号生成部１３２，１３４、ＤＡ（Digital to Analog）変換部１４２，１４４、π／２位相器１５０、及びレーザ発振部１５２を備えている。光変調部１１２，１１４は光信号生成部１１０を構成しており、フィルタ処理部１２２，１２４はフィルタ処理部１２０を構成している。 First, the configuration of the optical transmitter 10 will be described with reference to FIG. The optical transmission device 10 includes optical modulation units 112 and 114, filter processing units 122 and 124, drive signal generation units 132 and 134, DA (Digital-to-Analog) conversion units 142 and 144, a π / 2 phase shifter 150, and laser oscillation. Part 152 is provided. The optical modulation units 112 and 114 constitute an optical signal generation unit 110, and the filter processing units 122 and 124 constitute a filter processing unit 120.
　レーザ発振部１５２は、搬送波となるレーザ光を発振する。レーザ発振部１５２が生成したレーザ光は２つに分岐し、光変調部１１２及び光変調部１１４に入力される。 The laser oscillation unit 152 oscillates a laser beam that becomes a carrier wave. The laser beam generated by the laser oscillation unit 152 is branched into two and input to the light modulation unit 112 and the light modulation unit 114.
　駆動信号生成部１３２，１３４は、送信すべき信号に基づいた駆動信号を生成する。 The drive signal generators 132 and 134 generate drive signals based on signals to be transmitted.
　フィルタ処理部１２２は、駆動信号生成部１３２が生成した駆動信号に対してフィルタリング処理を行う。フィルタ処理部１２４は、駆動信号生成部１３４が生成した駆動信号に対してフィルタリング処理を行う。フィルタ処理部１２２が行うフィルタリング処理は、光変調部１１２が生成する光信号に対して、周波数別に、当該周波数における搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加えるものである。フィルタ処理部１２４が行うフィルタリング処理は、光変調部１１４が生成する光信号に対して、周波数別に、当該周波数における搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加えるものである。フィルタ処理部１２２及びフィルタ処理部１２４が光信号に加える位相回転の大きさは、互いに等しくても良いし、互いに異なっていても良い。なお、フィルタ処理部１２２，１２４は、例えばＦＩＲ（Finite Impulse Response）フィルタである。またフィルタ処理部１２２，１２４は、ルックアップテーブルを用いて上記した処理を行っても良い。 The filter processor 122 performs a filtering process on the drive signal generated by the drive signal generator 132. The filter processing unit 124 performs a filtering process on the drive signal generated by the drive signal generation unit 134. The filtering process performed by the filter processing unit 122 adds a phase rotation of a magnitude obtained by multiplying the square of the carrier wave deviation at the frequency by the same constant to the optical signal generated by the optical modulation unit 112 for each frequency. It is. The filtering process performed by the filter processing unit 124 applies, to the optical signal generated by the optical modulation unit 114, a phase rotation having a magnitude obtained by multiplying the square of the carrier wave deviation at the frequency by the same constant for each frequency. It is. The magnitude of the phase rotation applied to the optical signal by the filter processing unit 122 and the filter processing unit 124 may be equal to each other or may be different from each other. The filter processing units 122 and 124 are, for example, FIR (Finite Impulse Response) filters. The filter processing units 122 and 124 may perform the above-described processing using a lookup table.
　光変調部１１２は、フィルタ処理部１２２が処理した後の駆動信号に従ってレーザ光を変調して光信号を生成する。光変調部１１４は、フィルタ処理部１２４が処理した後の駆動信号に従ってレーザ光を変調して光信号を生成する。 The light modulator 112 modulates the laser beam according to the drive signal processed by the filter processor 122 to generate an optical signal. The light modulator 114 modulates the laser light according to the drive signal processed by the filter processor 124 to generate an optical signal.
　π／２位相器１５０は、光変調部１１４が生成した光信号の移送をπ／２変化させる。その後、光変調部１１２が生成した光信号と、光変調部１１４が生成した光信号は、合波されて送信用光信号になる。この送信用光信号は、光ファイバ３００を介して光受信装置２０に送信される。 The π / 2 phase shifter 150 changes the transfer of the optical signal generated by the light modulation unit 114 by π / 2. Thereafter, the optical signal generated by the optical modulation unit 112 and the optical signal generated by the optical modulation unit 114 are combined into an optical signal for transmission. This transmission optical signal is transmitted to the optical receiver 20 via the optical fiber 300.
　本実施形態に係る光通信システムは、さらに光ファイバ情報管理部３１０及び位相回転設定装置３２０を備えている。光ファイバ情報管理部３１０は、光ファイバ３００の延伸方向における送信用光信号の強度のピーク値又はＰＡＰＲの積算値を記憶する。これらの積算値は、光ファイバ情報管理部３１０が算出してもよいし、光ファイバ情報管理部３１０に外部から入力されても良い。位相回転設定装置３２０は、光ファイバ情報管理部３１０が記憶している情報に基づいて、フィルタ処理部１２２，１２４における位相回転量、またはフィルタ処理部１２２，１２４で加えるべき波長分散量を設定し、設定した値をフィルタ処理部１２２及びフィルタ処理部１２４に送信する。なお、位相回転設定装置３２０は、フィルタ処理部１２２及びフィルタ処理部１２４に送信する値を変えながら光ファイバ情報管理部３１０が記憶している積算値の変化を見ることにより、フィルタ処理部１２２及びフィルタ処理部１２４に送信する値の最適値を定めてもよい。 The optical communication system according to the present embodiment further includes an optical fiber information management unit 310 and a phase rotation setting device 320. The optical fiber information management unit 310 stores the peak value of the intensity of the transmission optical signal in the extending direction of the optical fiber 300 or the integrated value of PAPR. These integrated values may be calculated by the optical fiber information management unit 310 or may be input to the optical fiber information management unit 310 from the outside. The phase rotation setting device 320 sets the phase rotation amount in the filter processing units 122 and 124 or the chromatic dispersion amount to be added by the filter processing units 122 and 124 based on the information stored in the optical fiber information management unit 310. The set value is transmitted to the filter processing unit 122 and the filter processing unit 124. Note that the phase rotation setting device 320 changes the values transmitted to the filter processing unit 122 and the filter processing unit 124 while observing the change of the integrated value stored in the optical fiber information management unit 310, and thereby the filter processing unit 122 and An optimum value to be transmitted to the filter processing unit 124 may be determined.
　次に、図３を用いて、光受信装置２０の構成を説明する。光受信装置２０は、補償部２１０、局所光生成部２２０、９０°光ハイブリッド２２２、光ディテクタ２２４、ＡＤ（Analog to Digital）コンバータ２２６、波長分散補償部２２８、偏光分離部２３０、偏差補償部２３２、及びシンボル識別部２３４を有している。 Next, the configuration of the optical receiver 20 will be described with reference to FIG. The optical receiver 20 includes a compensation unit 210, a local light generation unit 220, a 90 ° optical hybrid 222, an optical detector 224, an AD (Analog-to-Digital) converter 226, a chromatic dispersion compensation unit 228, a polarization separation unit 230, and a deviation compensation unit 232. And a symbol identification unit 234.
　局所光生成部２２０は局所光を発振する。局所光は、搬送波とほぼ同一の周波数を有する。 The local light generator 220 oscillates local light. Local light has substantially the same frequency as the carrier wave.
　９０°光ハイブリッド２２２には、送信用光信号と、局所光生成部２１１からの局所光が入力される。９０°光ハイブリッド２２２は、光信号と局所光とを干渉させて４つの光信号を生成する。 The 90 ° optical hybrid 222 receives a transmission optical signal and local light from the local light generator 211. The 90 ° optical hybrid 222 generates four optical signals by causing the optical signal and local light to interfere with each other.
　光ディテクタ２２４は、９０°光ハイブリッド２２２が生成した４つの光信号を光電変換して、４つのアナログ信号を生成する。 The optical detector 224 photoelectrically converts the four optical signals generated by the 90 ° optical hybrid 222 to generate four analog signals.
　ＡＤコンバータ２２６は、光ディテクタ２２４が生成した４つのアナログ信号を、それぞれデジタル信号に変換する。 The AD converter 226 converts the four analog signals generated by the optical detector 224 into digital signals, respectively.
　補償部２１０は、ＡＤコンバータ２２６が生成した４つのデジタル信号それぞれに対して、位相回転設定装置３２０から送られてきた値に基づいて補償処理を行う。この補償処理は、光送信装置１０のフィルタ処理部１２０が送信用光信号に付与した光位相回転と、絶対値が同じであって符号が逆である光位相回転を加えるものである。 The compensation unit 210 performs compensation processing on each of the four digital signals generated by the AD converter 226 based on the values sent from the phase rotation setting device 320. This compensation processing adds optical phase rotation, which has the same absolute value and opposite sign, to the optical phase rotation given to the optical signal for transmission by the filter processing unit 120 of the optical transmission device 10.
　波長分散補償部２２８は、補償部２１０が処理した後の４つのデジタル信号に対して、光ファイバ３００において送信用光信号に加わった波長分散を補償する処理を行う。 The chromatic dispersion compensation unit 228 performs processing for compensating the chromatic dispersion added to the transmission optical signal in the optical fiber 300 on the four digital signals processed by the compensation unit 210.
　偏光分離部２３０は、４つのデジタル信号を用いて、送信されてきた情報を示す信号を生成する。 The polarization separation unit 230 generates a signal indicating the transmitted information using the four digital signals.
　偏差補償部２３２は、送信用光信号と局所光との間の周波数偏差と光位相偏差を補償する。これにより、光位相の回転に起因した信号のノイズが補償される。 The deviation compensation unit 232 compensates for a frequency deviation and an optical phase deviation between the transmission optical signal and the local light. Thereby, the noise of the signal due to the rotation of the optical phase is compensated.
　シンボル識別部２２３は、偏差補償部２３２によって補償された後の信号を用いて、シンボル判定を行う。これにより、送信された信号が復調される。 The symbol identification unit 223 performs symbol determination using the signal after compensation by the deviation compensation unit 232. Thereby, the transmitted signal is demodulated.
　なお、補償部２１０と波長分散補償部２２８の位置は逆であっても良い。 Note that the positions of the compensation unit 210 and the chromatic dispersion compensation unit 228 may be reversed.
　図４は、光信号の伝送距離と、光信号の強度のピーク値との関係を示す図である。本図に示す例において、点線は、フィルタ処理部１２０及び補償部２１０を動作させなかった場合のシミュレーション結果を示しており、実線は、フィルタ処理部１２０及び補償部２１０を動作させた場合のシミュレーション結果を示している。本図から、フィルタ処理部１２０及び補償部２１０を動作させることにより、光信号の強度のピーク値が変化することが分かる。 FIG. 4 is a diagram showing the relationship between the transmission distance of the optical signal and the peak value of the intensity of the optical signal. In the example shown in the figure, a dotted line indicates a simulation result when the filter processing unit 120 and the compensation unit 210 are not operated, and a solid line indicates a simulation when the filter processing unit 120 and the compensation unit 210 are operated. Results are shown. From this figure, it can be seen that the peak value of the intensity of the optical signal changes by operating the filter processing unit 120 and the compensation unit 210.
　図５は、フィルタ処理部１２０及び補償部２１０で加える位相回転（パラメータ値）の大きさと、光ファイバ３００の延伸方向における送信用信号の光強度のピーク値の積算量との関係を示す図である。本図から、パラメータを適切な値に設定すると、パラメータが０の場合、すなわちフィルタ処理部１２０及び補償部２１０を動作させない場合と比較して、光信号の強度のピーク値の積算値を下げられることが分かる。 FIG. 5 is a diagram illustrating a relationship between the magnitude of the phase rotation (parameter value) applied by the filter processing unit 120 and the compensation unit 210 and the integrated amount of the peak value of the light intensity of the transmission signal in the extending direction of the optical fiber 300. is there. From this figure, when the parameter is set to an appropriate value, the integrated value of the peak value of the intensity of the optical signal can be reduced as compared with the case where the parameter is 0, that is, when the filter processing unit 120 and the compensation unit 210 are not operated. I understand that.
　図６は、フィルタ処理部１２０及び補償部２１０で加える位相回転（パラメータ値）の大きさと、光受信装置２０で受信した信号のＱ値との関係を示す図である。本図から、パラメータを適切な値に設定すると、Ｑ値が上昇することが分かる。図５と図６を比べると、光信号の強度のピーク値の積算値が下がると、Ｑ値が上昇することが分かる。 FIG. 6 is a diagram illustrating the relationship between the magnitude of the phase rotation (parameter value) applied by the filter processing unit 120 and the compensation unit 210 and the Q value of the signal received by the optical receiver 20. From this figure, it can be seen that the Q value increases when the parameter is set to an appropriate value. Comparing FIG. 5 and FIG. 6, it can be seen that the Q value increases when the integrated value of the peak value of the intensity of the optical signal decreases.
　以上、本実施形態によっても、第１の実施形態と同様の効果を得ることができる。また、位相回転設定装置３２０は、光ファイバ情報管理部３１０が記憶している送信用光信号の強度のピーク値又はＰＡＰＲの積算値を認識しながら、フィルタ処理部１２０及び補償部２１０のパラメータを変更することができる。このため、位相回転設定装置３２０を用いることにより、フィルタ処理部１２０及び補償部２１０のパラメータを容易に設定することができる。 As described above, according to this embodiment, the same effect as that of the first embodiment can be obtained. Further, the phase rotation setting device 320 recognizes the peak value of the intensity of the optical signal for transmission stored in the optical fiber information management unit 310 or the integrated value of the PAPR, and sets the parameters of the filter processing unit 120 and the compensation unit 210. Can be changed. For this reason, the parameters of the filter processing unit 120 and the compensation unit 210 can be easily set by using the phase rotation setting device 320.
　なお本実施形態において、位相回転設定装置３２０を設けずに、光通信システムの管理者が、直接フィルタ処理部１２２，１２４及び補償部２１０のパラメータを設定しても良い。 In this embodiment, the administrator of the optical communication system may directly set the parameters of the filter processing units 122 and 124 and the compensation unit 210 without providing the phase rotation setting device 320.
（第３の実施形態）
　図７は、第３の実施形態に係る光送信装置１０の構成を示す図であり、図８は、第３の実施形態に係る光受信装置２０の構成を示す図である。本図に示す光送信装置１０及び光受信装置２０は、偏波多重方式で光信号の送受信を行う。光送信装置１０及び光受信装置２０の基本的な構成は、第２の実施形態と同様である。 (Third embodiment)
FIG. 7 is a diagram illustrating a configuration of the optical transmission device 10 according to the third embodiment, and FIG. 8 is a diagram illustrating a configuration of the optical reception device 20 according to the third embodiment. The optical transmitter 10 and the optical receiver 20 shown in this figure transmit and receive optical signals using the polarization multiplexing method. The basic configuration of the optical transmitter 10 and the optical receiver 20 is the same as that of the second embodiment.
　まず、図７を用いて光送信装置１０の構成について説明する。本実施形態において、光送信装置１０は、駆動信号生成部１３２、フィルタ処理部１２２、及びＤＡ変換部１４２を２組有している。１組目の駆動信号生成部１３２、フィルタ処理部１２２、及びＤＡ変換部１４２は、Ｉ相に対応する駆動信号を生成している。２組目の駆動信号生成部１３２、フィルタ処理部１２２、及びＤＡ変換部１４２は、Ｑ相に対応する駆動信号を生成している。そして２つのＤＡ変換部１４２から出力された駆動信号は、いずれも光変調部１１２に入力される。本実施形態において光変調部１１２は光Ｉ／Ｑ変調器である。 First, the configuration of the optical transmission device 10 will be described with reference to FIG. In the present embodiment, the optical transmission device 10 includes two sets of a drive signal generation unit 132, a filter processing unit 122, and a DA conversion unit 142. The first set of drive signal generation unit 132, filter processing unit 122, and DA conversion unit 142 generate drive signals corresponding to the I phase. The second set of drive signal generation unit 132, filter processing unit 122, and DA conversion unit 142 generate drive signals corresponding to the Q phase. The drive signals output from the two DA converters 142 are both input to the light modulator 112. In the present embodiment, the light modulation unit 112 is an optical I / Q modulator.
　また光送信装置１０は、駆動信号生成部１３４、フィルタ処理部１２４、及びＤＡ変換部１４４も２組有している。１組目の駆動信号生成部１３４、フィルタ処理部１２４、及びＤＡ変換部１４４は、Ｉ相に対応する駆動信号を生成している。２組目の駆動信号生成部１３４、フィルタ処理部１２４、及びＤＡ変換部１４４は、Ｑ相に対応する駆動信号を生成している。そして２つのＤＡ変換部１４４から出力された駆動信号は、いずれも光変調部１１４に入力される。本実施形態では、光変調部１１４も光Ｉ／Ｑ変調器である。 The optical transmission device 10 also includes two sets of the drive signal generation unit 134, the filter processing unit 124, and the DA conversion unit 144. The first set of drive signal generation unit 134, filter processing unit 124, and DA conversion unit 144 generate drive signals corresponding to the I phase. The second set of drive signal generator 134, filter processor 124, and DA converter 144 generates a drive signal corresponding to the Q phase. The drive signals output from the two DA converters 144 are both input to the light modulator 114. In the present embodiment, the light modulator 114 is also an optical I / Q modulator.
　２つのフィルタ処理部１２２及び２つのフィルタ処理部１２４は、いずれも位相回転設定装置３２０から送信された情報に従って、駆動信号に対して回転位相を加える処理を行う。 Both the two filter processing units 122 and the two filter processing units 124 perform a process of adding a rotation phase to the drive signal according to the information transmitted from the phase rotation setting device 320.
　また光送信装置１０は、多重化部１６０を有している。多重化部１６０は、光変調部１１２が生成した光信号（第１光信号）及び光変調部１１４が生成した光信号（第２光信号）を、互いの偏向状態が直交となるような状態で多重化することにより、送信用光信号を生成する。 Further, the optical transmission device 10 has a multiplexing unit 160. The multiplexing unit 160 is in a state in which the optical signal (first optical signal) generated by the optical modulation unit 112 and the optical signal (second optical signal) generated by the optical modulation unit 114 are orthogonal to each other. The optical signal for transmission is generated by multiplexing in the above.
　次に、図８を用いて光受信装置２０の構成について説明する。光受信装置２０は、以下の点を除いて、第２の実施形態に係る３０と同様の構成である。 Next, the configuration of the optical receiver 20 will be described with reference to FIG. The optical receiver 20 has the same configuration as 30 according to the second embodiment except for the following points.
　まず、９０°光ハイブリッド２２２は、光信号と局所光とを位相差０で干渉させて光信号（Ｉｘ）を生成し、光信号と局所光とを位相差π／２で干渉させて光信号（Ｑｘ）を生成する。また９０°光ハイブリッド２２２は、光信号と局所光とを位相差０で干渉させて光信号（Ｉｙ）を生成し、光信号と局所光とを位相差π／２で干渉させて光信号（Ｑｙ）を生成する。 First, the 90 ° optical hybrid 222 generates an optical signal (I x ) by causing an optical signal and local light to interfere with each other with a phase difference of 0, and causes the optical signal and local light to interfere with each other with a phase difference of π / 2. A signal (Q x ) is generated. The 90 ° optical hybrid 222 generates an optical signal (I y ) by causing the optical signal and local light to interfere with each other with a phase difference of 0, and causes the optical signal and local light to interfere with each other with a phase difference of π / 2. (Q y ) is generated.
　そして偏光分離部２３０は、波長分散補償部２２８が出力した信号Ｉｘ、Ｑｘ、Ｉｙ、及びＱｙを用いて、２チャンネルの信号Ｅｘｉｎ（ｔ）＝Ｉｘ＋ｊＱｘ、及びＥｙｉｎ（ｔ）＝Ｉｙ＋ｊＱｙを生成する。Ｅｘｉｎ（ｔ）は光変調部１１２が送信してきた信号を示しており、Ｅｙｉｎ（ｔ）は光変調部１１４が送信してきた信号を示している。 Then, the polarization separation unit 230 generates two-channel signals E xin (t) = Ix + jQx and E yin (t) = Iy + jQy using the signals Ix, Qx, Iy, and Qy output from the chromatic dispersion compensation unit 228. To do. E xin (t) indicates a signal transmitted from the light modulator 112, and E yin (t) indicates a signal transmitted from the light modulator 114.
　そして、偏差補償部２３２及びシンボル識別部２３４は、２組設けられている。１組目の偏差補償部２３２及びシンボル識別部２３４は、Ｅｘｉｎ（ｔ）を処理する。２組目の偏差補償部２３２及びシンボル識別部２３４は、Ｅｙｉｎ（ｔ）を処理する。 Two sets of the deviation compensating unit 232 and the symbol identifying unit 234 are provided. The first set of deviation compensation unit 232 and symbol identification unit 234 processes E xin (t). The second set of deviation compensation unit 232 and symbol identification unit 234 processes E yin (t).
　本実施形態において、光ファイバ情報管理部３１０は、送信用光信号のうち、光変調部１１２が生成した光信号に相当する偏波成分の、光ファイバ３００の延伸方向における強度のピーク値又はＰＡＰＲの積算値と、光変調部１１４が生成した光信号に相当する偏波成分の、光ファイバ３００の延伸方向における強度のピーク値又はＰＡＰＲの積算値とを、それぞれ記憶している。そして位相回転設定装置３２０は、これら２つのピーク値（又はＰＡＰＲ）の積算値を加算した値に基づいて、フィルタ処理部１２２，１２４を制御する。ここで、位相回転設定装置３２０は、２つの積算値に互いに異なる係数を乗じた上で、これら２つの値を加算してもよい。位相回転設定装置３２０は、好ましくは、２つの積算値を加算した値が最小となるように、フィルタ処理部１２２，１２４を制御する。 In the present embodiment, the optical fiber information management unit 310 includes the intensity peak value or PAPR of the polarization component corresponding to the optical signal generated by the optical modulation unit 112 in the extending direction of the optical fiber 300 among the transmission optical signals. And the intensity peak value or PAPR integrated value of the polarization component corresponding to the optical signal generated by the optical modulation unit 114 in the extending direction of the optical fiber 300 are stored. Then, the phase rotation setting device 320 controls the filter processing units 122 and 124 based on a value obtained by adding the integrated values of these two peak values (or PAPR). Here, the phase rotation setting device 320 may add these two values after multiplying the two integrated values by different coefficients. The phase rotation setting device 320 preferably controls the filter processing units 122 and 124 so that a value obtained by adding the two integrated values is minimized.
　本実施形態によれば、偏波多重方式の光通信システムにおいても、第２の実施形態と同様の効果を得ることができる。 According to the present embodiment, the same effect as that of the second embodiment can be obtained also in the polarization multiplexing optical communication system.
（第４の実施形態）
　図９は、第４の実施形態に係る光通信システムで用いられる光受信装置２０の構成を示す図である。本実施形態に係る光受信装置２０は、波長分散補償部２２８が補償部２１０の機能を兼ねている点を除いて、第２の実施形態に係る光受信装置２０と同様の構成である。なお、第３の実施形態に係る光受信装置２０においても、波長分散補償部２２８が補償部２１０の機能を兼ねていてもよい。 (Fourth embodiment)
FIG. 9 is a diagram illustrating a configuration of an optical receiver 20 used in the optical communication system according to the fourth embodiment. The optical receiver 20 according to the present embodiment has the same configuration as that of the optical receiver 20 according to the second embodiment, except that the chromatic dispersion compensation unit 228 also functions as the compensation unit 210. In the optical receiver 20 according to the third embodiment, the chromatic dispersion compensator 228 may also function as the compensator 210.
　本実施形態において、フィルタ処理部１２２，１２４が加える位相回転の大きさ（すなわち波長分散の大きさ）は、波長分散補償部２２８が補償できる波長分散の大きさ以下となっている。 In this embodiment, the magnitude of the phase rotation (that is, the magnitude of chromatic dispersion) applied by the filter processing sections 122 and 124 is equal to or less than the magnitude of chromatic dispersion that can be compensated by the chromatic dispersion compensating section 228.
　本実施形態によっても、第２の実施形態と同様の効果を得ることができる。また補償部２１０を設ける必要がないため、光受信装置２０の構造を簡単にすることができる。 Also in this embodiment, the same effect as that of the second embodiment can be obtained. Further, since it is not necessary to provide the compensation unit 210, the structure of the optical receiver 20 can be simplified.
（第５の実施形態）
　図１０は、第５の実施形態に係る光通信システムで用いられる光受信装置２０の構成を示す図である。本実施形態に係る光受信装置２０は、補償部２１０の代わりに光学的分散補償部２３６が設けられている点を除いて、第２の実施形態に係る光受信装置２０と同様の構成である。光学的分散補償部２３６は、例えば分散補償ファイバであり、光学的に光の分散を補償する補償器である。なお、第３の実施形態に係る光受信装置２０においても、補償部２１０の代わりに光学的分散補償部２３６が設けられていても良い。 (Fifth embodiment)
FIG. 10 is a diagram illustrating a configuration of an optical receiver 20 used in the optical communication system according to the fifth embodiment. The optical receiving apparatus 20 according to the present embodiment has the same configuration as the optical receiving apparatus 20 according to the second embodiment, except that an optical dispersion compensation unit 236 is provided instead of the compensation unit 210. . The optical dispersion compensation unit 236 is, for example, a dispersion compensation fiber, and is a compensator that optically compensates for dispersion of light. Note that, also in the optical receiving device 20 according to the third embodiment, an optical dispersion compensation unit 236 may be provided instead of the compensation unit 210.
　本実施形態によっても、第２の実施形態と同様の効果を得ることができる。また、フィルタ処理部１２２，１２４が加える位相回転（すなわち波長分散）を、光学的に補償することができるため、デジタル処理回路を簡単にすることができる。 Also in this embodiment, the same effect as that of the second embodiment can be obtained. In addition, since the phase rotation (that is, chromatic dispersion) applied by the filter processing units 122 and 124 can be optically compensated, the digital processing circuit can be simplified.
（第６の実施形態）
　図１１は、第６の実施形態に係る光通信システムの構成を示す図である。本図に示す例において、光通信システムは、光受信装置２０を複数有している。そしてフィルタ処理部１２０は、送信先となる光受信装置２０に応じて、位相回転の大きさを異ならせる。なお、光送信装置１０及び光受信装置２０の構成の詳細は、第１～第５の実施形態のいずれかと同様である。 (Sixth embodiment)
FIG. 11 is a diagram illustrating a configuration of an optical communication system according to the sixth embodiment. In the example shown in this figure, the optical communication system has a plurality of optical receivers 20. And the filter process part 120 changes the magnitude | size of a phase rotation according to the optical receiver 20 used as a transmission destination. The details of the configurations of the optical transmitter 10 and the optical receiver 20 are the same as those in any of the first to fifth embodiments.
　送信先となる光受信装置２０が異なると、送信用光信号を伝達する光ファイバの長さなどが異なるため、必要となる位相回転の大きさも異なる。本実施形態では、フィルタ処理部１２０は、送信先となる光受信装置２０に応じて、位相回転の大きさを異ならせるため、いずれの光受信装置２０に送信用光信号を送信する場合においても、上記した実施形態と同様の効果を得ることができる。 If the optical receiver 20 that is the transmission destination is different, the length of the optical fiber that transmits the optical signal for transmission is different, so that the required phase rotation is different. In the present embodiment, the filter processing unit 120 varies the magnitude of the phase rotation depending on the optical receiver 20 that is the transmission destination, and therefore, even when transmitting the optical signal for transmission to any of the optical receivers 20 The same effects as those of the above-described embodiment can be obtained.
　以上、図面を参照して本発明の実施形態について述べたが、これらは本発明の例示であり、上記以外の様々な構成を採用することもできる。 As described above, the embodiments of the present invention have been described with reference to the drawings. However, these are exemplifications of the present invention, and various configurations other than the above can be adopted.
　この出願は、２０１２年３月１２日に出願された日本出願特願２０１２－５４０９７を基礎とする優先権を主張し、その開示の全てをここに取り込む。 This application claims priority based on Japanese Patent Application No. 2012-54097 filed on Mar. 12, 2012, the entire disclosure of which is incorporated herein.

Claims (15)

  1. 　送信用光信号を送信する光送信装置と、
    　前記送信用光信号を受信する光受信装置と、
    を備え、
    　前記光送信装置は、
    　　搬送波を変調することにより前記送信用光信号を生成する光信号生成手段と、
    　　前記送信用光信号に対して、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理を行うフィルタ処理手段と、
    を有し、
    　前記光受信装置は、前記送信用光信号に基づいて生成された信号に対して、前記フィルタ処理手段が前記送信用光信号に加えた前記位相回転を補償する処理を行う補償手段を有する光通信システム。     An optical transmitter for transmitting an optical signal for transmission;
    An optical receiver for receiving the optical signal for transmission;
    With
    The optical transmitter is
    Optical signal generating means for generating the transmission optical signal by modulating a carrier wave;
    Filter processing means for performing a process of adding a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave to the transmission optical signal;
    Have
    The optical receiver includes a compensation unit that performs a process of compensating the phase rotation added to the transmission optical signal by the filter processing unit with respect to a signal generated based on the transmission optical signal. system.
  2. 　請求項１に記載の光通信システムにおいて、
    　前記位相回転は、前記光送信装置と前記光受信装置の間の光ファイバにおいて、光強度のピーク値の前記光ファイバの延伸方向における積算値又は光強度のＰＡＰＲ（Peak to Average Power Ratio）の前記光ファイバの延伸方向における積算値が最小となるように設定されている光通信システム。     The optical communication system according to claim 1,
    In the optical fiber between the optical transmitting device and the optical receiving device, the phase rotation is the integrated value of the peak value of the light intensity in the extending direction of the optical fiber or the PAPR (Peak to Average Power Ratio) of the light intensity. An optical communication system that is set so that an integrated value in a drawing direction of an optical fiber is minimized.
  3. 　送信用光信号を送信する光送信装置と、
    　前記送信用光信号を受信する光受信装置と、
    を備え、
    　前記光送信装置は、
    　　搬送波を変調することにより前記送信用光信号を生成する光信号生成手段と、
    　　前記光送信装置と前記光受信装置の間の光ファイバにおいて、光強度のピーク値の前記光ファイバの延伸方向における積算値又は光強度のＰＡＰＲ（Peak to Average Power Ratio）の前記光ファイバの延伸方向における積算値が最小となるように、前記送信用光信号に位相回転を加えるフィルタ処理手段と、
    を有し、
    　前記光受信装置は、前記送信用光信号に基づいて生成された信号に対して、前記フィルタ処理手段が前記送信用光信号に加えた前記位相回転を補償する処理を行う補償手段を有する光通信システム。     An optical transmitter for transmitting an optical signal for transmission;
    An optical receiver for receiving the optical signal for transmission;
    With
    The optical transmitter is
    Optical signal generating means for generating the transmission optical signal by modulating a carrier wave;
    In the optical fiber between the optical transmitter and the optical receiver, the integrated value of the peak value of the light intensity in the extending direction of the optical fiber or the extending direction of the optical fiber of PAPR (Peak to Average Power Ratio) of the light intensity Filter processing means for applying phase rotation to the transmission optical signal so that the integrated value at
    Have
    The optical receiver includes a compensation unit that performs a process of compensating the phase rotation added to the transmission optical signal by the filter processing unit with respect to a signal generated based on the transmission optical signal. system.
  4. 　請求項３に記載の光通信システムにおいて、
    　前記フィルタ処理手段は、前記搬送波の周波数別に前記位相回転を加える光通信システム。     The optical communication system according to claim 3.
    The optical communication system, wherein the filter processing unit applies the phase rotation for each frequency of the carrier wave.
  5. 　請求項２～４のいずれか一項に記載の光通信システムにおいて、
    　前記光送信装置は、
    　　第１光信号を生成する第１光信号生成手段と、
    　　前記第１光信号と偏光状態が直交し、かつ搬送波の周波数帯が同一である第２光信号を生成する第２光信号生成手段と、
    　　前記第１光信号と前記第２光信号を多重化して前記送信用光信号を生成する多重化手段と、
    を有し、
    　前記光受信装置は、前記送信用光信号から、前記第１光信号及び前記第２光信号を互いに分離する分離手段を有する光通信システム。     The optical communication system according to any one of claims 2 to 4,
    The optical transmitter is
    First optical signal generating means for generating a first optical signal;
    Second optical signal generating means for generating a second optical signal having a polarization state orthogonal to the first optical signal and having the same carrier frequency band;
    Multiplexing means for multiplexing the first optical signal and the second optical signal to generate the optical signal for transmission;
    Have
    An optical communication system, wherein the optical receiving device includes a separating unit that separates the first optical signal and the second optical signal from the transmission optical signal.
  6. 　請求項５に記載の光通信システムにおいて、
    　前記フィルタ処理手段は、前記第１光信号の前記積算値と、前記第２光信号の前記積算値との和が最小となるように前記位相回転を加える光通信システム。     The optical communication system according to claim 5.
    The optical communication system, wherein the filter processing unit applies the phase rotation so that a sum of the integrated value of the first optical signal and the integrated value of the second optical signal is minimized.
  7. 　請求項６に記載の光通信システムにおいて、
    　前記フィルタ処理手段は、前記第１光信号の前記積算値に第１係数を乗じた値と、前記第２光信号の前記積算値に第２係数を乗じた値との和が最小となるように前記位相回転を加える光通信システム。     The optical communication system according to claim 6,
    The filter processing unit may minimize a sum of a value obtained by multiplying the integrated value of the first optical signal by a first coefficient and a value obtained by multiplying the integrated value of the second optical signal by a second coefficient. An optical communication system for applying the phase rotation to the.
  8. 　請求項１～７のいずれか一項に記載の光通信システムにおいて、
    　複数の前記光受信装置を有し、
    　前記フィルタ処理手段は、前記複数の光受信装置別に、前記位相回転の大きさを異ならせる光通信システム。     The optical communication system according to any one of claims 1 to 7,
    A plurality of the optical receivers;
    The optical communication system in which the filter processing unit varies the magnitude of the phase rotation for each of the plurality of optical receivers.
  9. 　請求項１～８のいずれか一項に記載の光通信システムにおいて、
    　前記フィルタ処理手段及び前記補償手段に、前記位相回転の大きさを示す情報を送信する位相回転設定装置をさらに備え、
    　前記フィルタ処理手段及び前記補償手段は、前記位相回転設定装置から受信した前記情報に基づいて動作する光通信システム。     The optical communication system according to any one of claims 1 to 8,
    A phase rotation setting device that transmits information indicating the magnitude of the phase rotation to the filter processing unit and the compensation unit;
    The optical communication system in which the filter processing unit and the compensation unit operate based on the information received from the phase rotation setting device.
  10. 　搬送波を変調することにより送信用光信号を生成する光信号生成手段と、
    　前記送信用光信号に対して、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理を行うフィルタ処理手段と、
    を備える光送信装置。     An optical signal generating means for generating an optical signal for transmission by modulating a carrier wave;
    Filter processing means for performing a process of adding a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave to the transmission optical signal;
    An optical transmission device comprising:
  11. 　光送信装置から送信された送信用光信号に基づいて生成された信号にフィルタ処理を行う補償手段を備え、
    　前記送信用光信号は、搬送波を変調することにより生成されており、かつ、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理が加えられており、
    　前記補償手段は、前記位相回転を補償する処理を行う光受信装置。     Compensating means for performing a filtering process on a signal generated based on a transmission optical signal transmitted from an optical transmission device,
    The transmission optical signal is generated by modulating a carrier wave, and for each frequency of the carrier wave, a phase rotation having a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant is applied. Processing has been added,
    The compensation means is an optical receiver that performs processing to compensate for the phase rotation.
  12. 　送信用光信号を送信する光送信装置と、
    　前記送信用光信号を受信する光受信装置と、
    を備える光通信システムと共に使用され、
    　　前記光送信装置は、
    　　搬送波を変調することにより前記送信用光信号を生成する光信号生成手段と、
    　　前記送信用光信号に対して、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理を行うフィルタ処理手段と、
    を有し、
    　前記光受信装置は、前記送信用光信号に基づいて生成された信号に、前記フィルタ処理手段が前記送信用光信号に加えた前記位相回転を補償する補償手段を有し、
    　前記フィルタ処理手段及び前記補償手段に、前記位相回転の大きさを示す情報を送信する位相回転設定装置。     An optical transmitter for transmitting an optical signal for transmission;
    An optical receiver for receiving the optical signal for transmission;
    Used with an optical communication system comprising:
    The optical transmitter is
    Optical signal generating means for generating the transmission optical signal by modulating a carrier wave;
    Filter processing means for performing a process of adding a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant for each frequency of the carrier wave to the transmission optical signal;
    Have
    The optical receiver includes a compensation unit that compensates for the phase rotation added to the optical signal for transmission by the filter processing unit in a signal generated based on the optical signal for transmission;
    A phase rotation setting device that transmits information indicating the magnitude of the phase rotation to the filter processing unit and the compensation unit.
  13. 　光送信装置が、搬送波を変調することにより送信用光信号を生成し、かつ前記送信用光信号に、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加え、
    　光受信装置が、前記送信用光信号に基づいて生成された信号に、前記位相回転を補償する光通信方法。     An optical transmission device generates a transmission optical signal by modulating a carrier wave, and multiplies the transmission optical signal by the same constant to the square of the deviation of the carrier wave at the frequency for each frequency of the carrier wave. Add a phase rotation of magnitude,
    An optical communication method in which an optical receiver compensates the phase rotation for a signal generated based on the transmission optical signal.
  14. 　搬送波を変調することにより送信用光信号を生成し、かつ前記送信用光信号に対して、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理を行ってから、前記送信用光信号を送信する光送信方法。 A transmission optical signal is generated by modulating a carrier, and the transmission optical signal has a magnitude obtained by multiplying the square of the deviation of the carrier at the frequency by the same constant for each frequency of the carrier. An optical transmission method for transmitting the optical signal for transmission after performing processing for applying phase rotation.
  15. 　搬送波を変調することにより生成されており、かつ、前記搬送波の周波数別に、当該周波数における前記搬送波の偏差の２乗に同一の定数を乗じた大きさの位相回転を加える処理が行われた送信用光信号を受信し、前記送信用光信号に基づいて生成された信号に対して、前記位相回転を補償する処理を行う光受信方法。 For transmission, which is generated by modulating a carrier wave, and for which a process of adding a phase rotation of a magnitude obtained by multiplying the square of the deviation of the carrier wave at the frequency by the same constant is performed for each frequency of the carrier wave An optical receiving method for receiving an optical signal and performing a process of compensating for the phase rotation on a signal generated based on the transmission optical signal.
PCT/JP2013/000387 2012-03-12 2013-01-25 Optical communications system, optical transmission device, optical reception device, optical communications method, optical transmission method, phase rotation setting device, and optical reception method WO2013136651A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012054097 2012-03-12
JP2012-054097 2012-03-12

Publications (1)

Publication Number Publication Date
WO2013136651A1 true WO2013136651A1 (en) 2013-09-19

Family

ID=49160604

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/000387 WO2013136651A1 (en) 2012-03-12 2013-01-25 Optical communications system, optical transmission device, optical reception device, optical communications method, optical transmission method, phase rotation setting device, and optical reception method

Country Status (1)

Country Link
WO (1) WO2013136651A1 (en)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0774699A (en) * 1993-09-03 1995-03-17 Hitachi Ltd Optical transmission system
JPH08288904A (en) * 1995-04-11 1996-11-01 Nippon Telegr & Teleph Corp <Ntt> Optical pulse transmission system
JP2004125837A (en) * 2002-09-30 2004-04-22 Mitsubishi Electric Corp Variable dispersion compensating device and its power supply circuit
JP2006518579A (en) * 2003-02-07 2006-08-10 フランス・テレコム Apparatus and method for high-speed optical transmission, and use of the apparatus and method
JP2008236512A (en) * 2007-03-22 2008-10-02 Mitsubishi Electric Corp Dispersion pre-equalizing optical transmitter
JP2009296259A (en) * 2008-06-04 2009-12-17 Sumitomo Electric Ind Ltd Optical transceiver, and optical transmission system
WO2010140289A1 (en) * 2009-06-05 2010-12-09 日本電気株式会社 Optical communication system, optical receiver of same, and optical communication method of same
JP2011142583A (en) * 2010-01-08 2011-07-21 Fujitsu Ltd Light receiving device and light receiving method
JP2011211516A (en) * 2010-03-30 2011-10-20 Hitachi Ltd Optical transmission apparatus, optical transmission method, and optical transmission and reception system

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0774699A (en) * 1993-09-03 1995-03-17 Hitachi Ltd Optical transmission system
JPH08288904A (en) * 1995-04-11 1996-11-01 Nippon Telegr & Teleph Corp <Ntt> Optical pulse transmission system
JP2004125837A (en) * 2002-09-30 2004-04-22 Mitsubishi Electric Corp Variable dispersion compensating device and its power supply circuit
JP2006518579A (en) * 2003-02-07 2006-08-10 フランス・テレコム Apparatus and method for high-speed optical transmission, and use of the apparatus and method
JP2008236512A (en) * 2007-03-22 2008-10-02 Mitsubishi Electric Corp Dispersion pre-equalizing optical transmitter
JP2009296259A (en) * 2008-06-04 2009-12-17 Sumitomo Electric Ind Ltd Optical transceiver, and optical transmission system
WO2010140289A1 (en) * 2009-06-05 2010-12-09 日本電気株式会社 Optical communication system, optical receiver of same, and optical communication method of same
JP2011142583A (en) * 2010-01-08 2011-07-21 Fujitsu Ltd Light receiving device and light receiving method
JP2011211516A (en) * 2010-03-30 2011-10-20 Hitachi Ltd Optical transmission apparatus, optical transmission method, and optical transmission and reception system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
R. KILLEY: "Dispersion and nonlinearity compensation using electronic predistortion techniques", THE IEE SEMINAR ON OPTICAL FIBRE COMMUNICATIONS AND ELECTRONIC SIGNAL PROCESSING, 15 December 2005 (2005-12-15) *

Similar Documents

Publication Publication Date Title
JP5760419B2 (en) Optical transmission device and optical transmission method
JP6319487B1 (en) Optical transmission characteristic estimation method, optical transmission characteristic compensation method, optical transmission characteristic estimation system, and optical transmission characteristic compensation system
JP5850041B2 (en) Optical receiver, polarization separation device, and optical reception method
WO2011052423A1 (en) Pre-equalisation optical transmitter and pre-equalisation optical fibre transmission system
JP2010050578A (en) Distortion compensator, optical receiver, control methods therefor, and optical transmission system
WO2018161355A1 (en) Signal transmitting method, signal receiving method, related device, and system
JP6107815B2 (en) Optical transmission device, optical communication system, optical reception device, optical transmission device adjustment method, optical transmission method, and optical reception method
US9608732B2 (en) Optical transmitter, optical communication system, and optical communication method
JP2019041285A (en) Optical transmission characteristic compensation system and optical transmission characteristic compensation method
WO2014155775A1 (en) Signal processing device, optical communication system, and signal processing method
JP4905951B2 (en) Optical modulation circuit and optical transmission system
JP6418973B2 (en) Dispersion compensation method, optical signal transmitter, and optical communication system
US9722697B2 (en) Polarization division multiplexing optical communication reception device, polarization division multiplexing optical communication system, and polarization division multiplexing optical communication method
JP6355465B2 (en) Optical receiver, transmitter / receiver, optical communication system, and waveform distortion compensation method
WO2013136651A1 (en) Optical communications system, optical transmission device, optical reception device, optical communications method, optical transmission method, phase rotation setting device, and optical reception method
WO2013140970A1 (en) Optical communication system and optical communication method having high phase noise resistance
JP6191595B2 (en) Optical communication system, optical transmission apparatus, optical communication method, and optical transmission method
JP2017195561A (en) Digital signal processing circuit and signal processing apparatus including multiple digital signal processing circuits
JP6116001B2 (en) Optical transmitter and optical receiver
JP5182154B2 (en) Optical communication system
Devi et al. 5× 222 Gb/s PM-16QAM Nyquist-WDM Superchannel
JP2016082347A (en) Optical transmitter, optical receiver and optical transmission and reception method
JP2010136146A (en) Optical receiving device
JP2007036785A (en) Optical transmission system

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: 13761232

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13761232

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP