WO2015004838A1 - 光通信システム、光受信器、光受信器の制御方法及び非一時的なコンピュータ可読媒体 - Google Patents
光通信システム、光受信器、光受信器の制御方法及び非一時的なコンピュータ可読媒体 Download PDFInfo
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- WO2015004838A1 WO2015004838A1 PCT/JP2014/002737 JP2014002737W WO2015004838A1 WO 2015004838 A1 WO2015004838 A1 WO 2015004838A1 JP 2014002737 W JP2014002737 W JP 2014002737W WO 2015004838 A1 WO2015004838 A1 WO 2015004838A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/25—Arrangements specific to fibre transmission
- H04B10/2507—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/548—Phase or frequency modulation
- H04B10/556—Digital modulation, e.g. differential phase shift keying [DPSK] or frequency shift keying [FSK]
- H04B10/5561—Digital phase modulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/612—Coherent receivers for optical signals modulated with a format different from binary or higher-order PSK [X-PSK], e.g. QAM, DPSK, FSK, MSK, ASK
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/614—Coherent receivers comprising one or more polarization beam splitters, e.g. polarization multiplexed [PolMux] X-PSK coherent receivers, polarization diversity heterodyne coherent receivers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/616—Details of the electronic signal processing in coherent optical receivers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/616—Details of the electronic signal processing in coherent optical receivers
- H04B10/6161—Compensation of chromatic dispersion
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
- H04L27/20—Modulator circuits; Transmitter circuits
- H04L27/2096—Arrangements for directly or externally modulating an optical carrier
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
- H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
- H04L27/38—Demodulator circuits; Receiver circuits
- H04L27/3809—Amplitude regulation arrangements
Definitions
- the present invention relates to an optical communication system, an optical receiver, an optical receiver control method, and a non-transitory computer-readable medium.
- An object of the present invention is to provide an optical communication system that controls the reception sensitivity of an optical receiver according to chromatic dispersion.
- An optical communication system is an optical communication system including an optical transmitter that inputs a data signal, modulates the optical signal, and transmits the optical signal; and an optical receiver that receives the optical signal and demodulates the data signal.
- the optical receiver comprises: photoelectric conversion means for converting the optical signal into an analog electric signal; conversion demodulation means for converting the analog electric signal into a digital signal and demodulating the data signal; and the analog electric signal Amplitude control means for controlling the amplitude of the analog electric signal according to the chromatic dispersion of the optical signal.
- An optical receiver includes a photoelectric conversion unit that converts an optical signal into an analog electric signal, a conversion demodulation unit that converts the analog electric signal into a digital signal and demodulates the data into a data signal, and an amplitude of the analog electric signal
- the amplitude control means controls the amplitude of the analog electric signal according to the chromatic dispersion of the optical signal.
- An optical receiver control method is configured such that the optical receiver converts an optical signal into an analog electric signal, converts the analog electric signal into a digital signal, and demodulates the data signal, and controls the control
- the method comprises controlling the amplitude of the analog electrical signal in response to chromatic dispersion of the optical signal.
- a non-transitory computer readable medium causes a computer to perform a control method of an optical receiver.
- the optical receiver is configured to convert an optical signal into an analog electrical signal, convert the analog electrical signal into a digital signal, and demodulate it into a data signal, and the control method is adapted to chromatic dispersion of the optical signal. In response, controlling the amplitude of the analog electrical signal.
- the above-described aspect can provide an optical communication system that controls the reception sensitivity of the optical receiver.
- FIG. 1 is a diagram of a communication system 100 according to a first exemplary embodiment of the present invention. It is a figure of the optical transmitter 1 concerning Embodiment 1 of this invention. It is a figure of the optical receiver 2 concerning Embodiment 1 of this invention. It is a figure of the amplitude control part 102 concerning Embodiment 1 of this invention. It is a flowchart of the communication method concerning Embodiment 1 of this invention. It is a sequence diagram of the communication method concerning Embodiment 1 of this invention. It is a figure of the communication system 300 concerning Embodiment 2 of this invention. It is a figure of the optical transmitter 3 concerning Embodiment 2 of this invention. It is a figure of the optical receiver 4 concerning Embodiment 2 of this invention. It is a figure of the amplitude control part 302 concerning Embodiment 2 of this invention. It is a flowchart of the communication method concerning Embodiment 2 of this invention. It is a figure of the communication system of the technique relevant to this invention.
- FIG. 12 shows a communication system 500 which is a related technique of the present invention.
- the digital coherent receiver 560 in FIG. 12 receives the signal light transmitted from the optical transmitter 550, causes the local light to interfere with the 90-degree hybrid circuit 522, and converts it into an analog electrical signal by coherent detection in a PD (Photo Diode) 523. Then, the signal amplitude is made constant in the analog amplifier 524 and input to an ADC (Analog / Digital Converter) unit 501 of a DSP (Digital Signal Processor) 525.
- ADC Analog / Digital Converter
- the analog amplifier 524 is gain-controlled so that the average amplitude of the analog electric signal converted into the electric signal is constant.
- the received optical signal is affected by the chromatic dispersion of the optical fiber that is the transmission path, and the time is increased.
- the signal waveform spreads in the axial direction.
- Chromatic dispersion is a phenomenon in which the width of an optical signal broadens in time because light having different wavelengths is transmitted through the optical fiber at different speeds while an optical pulse propagates through the optical fiber. Then, by superimposing several waveforms spread in the time axis direction, the amplitude of the received signal spreads and the waveform changes randomly.
- the ADC unit 501 Since the analog signal is digitally processed by the DSP 525, the ADC unit 501 needs to convert the entire analog signal amplitude into a digital signal. For this reason, the peak (maximum value) of the analog signal input to the ADC unit 501 is equal to or less than the dynamic range of the ADC unit 501 (the minimum value and the maximum value width of the identifiable analog signal input range). The output needs to be controlled.
- the output amplitude of the analog amplifier 524 is monitored, and a reference value (reference value) output from the reference generation circuit 526 set in advance in the comparator 527 is used. There is a method of comparing the output amplitude and feeding back to the gain control of the analog amplifier 524.
- the reference value output from the reference generation circuit 526 is fixed, and the reference value is set according to the maximum value of the chromatic dispersion of the transmission line. For this reason, even when the dispersion value is small and the distortion of the signal waveform is small, the signal amplitude is controlled to be small.
- the signal amplitude can be expanded and the resolution in the ADC can be relatively increased.
- the signal amplitude is constant, the input signal amplitude to the ADC unit 501 does not change.
- there is a problem that the reception sensitivity of the optical receiver is not different from that when the chromatic dispersion is maximum.
- the input amplitude of the ADC is set uniformly regardless of the chromatic dispersion value.
- the waveform of the received signal is distorted due to the chromatic dispersion and the amplitude peak becomes large. If uniform amplitude control is performed on the received signal, the dynamic range of the ADC will be exceeded. Therefore, it has been confirmed that the reception sensitivity is improved when the reference value input to the comparator 527 is set small and the analog signal amplitude input to the ADC is reduced.
- the reference value is set small, the signal amplitude after dispersion compensation also becomes small.
- the waveform distortion is small and the amplitude peak is small, but the analog signal amplitude inputted to the ADC remains small, and there is a problem that the reception sensitivity is not improved.
- the present invention has been made based on such a background, and embodiments will be described below.
- FIG. 1 shows a configuration example of an optical communication system 100 according to this embodiment.
- FIG. 1 shows a DP-QPSK (Dual Polarization-Quadrature Phase Shift Keying) type optical transmitter and a digital coherent type optical receiver.
- the optical communication system 100 includes a DP-QPSK transmitter (optical transmitter) 1 and a digital coherent DP-QPSK receiver (optical receiver) 2.
- FIG. 2 is a diagram showing the configuration of the optical transmitter 1.
- the optical transmitter 1 includes a circuit for generating and transmitting a DP-QPSK signal.
- the optical transmitter 1 includes an LD (Laser Diode) 11 that generates CW (Continuous Wave) light serving as a light source of signal light, and DP-QPSK CW light of the LD 11 by an input electric signal (input signal). And a DP-QPSK modulator 12 for modulation.
- LD Laser Diode
- CW Continuous Wave
- the DP-QPSK modulator 12 divides the CW light into two, QPSK modulation is performed on each of them, and the polarization planes are orthogonalized at 90 degrees and combined to generate a polarization multiplexed signal.
- the optical transmitter 1 describes the configuration of a general DP-QPSK transmitter.
- FIG. 3 is a diagram showing the configuration of the optical receiver 2.
- the optical receiver 2 receives an optical signal, interferes with local light, converts the optical signal into an electrical signal, converts the analog electrical signal input from the photoelectric conversion unit 101 into a digital signal,
- a conversion demodulator (DSP: Digital Signal Processor) 25 that performs chromatic dispersion compensation and DP-QPSK signal demodulation by processing, and an amplitude controller 102 are provided.
- DSP Digital Signal Processor
- the photoelectric conversion unit 101 includes a local light generation unit (LO; Local Oscillator) 21 that generates local light, a 90-degree hybrid circuit 22 that inputs and interferes with the received DP-QPSK signal and local light from the LO 21, A PD (Photo Diode) 23 that coherently detects an optical signal interfered by the 90-degree hybrid circuit 22 and converts it into an analog electrical signal, and an analog electrical signal from the PD 23 is input and gain control from a comparator (COMP) 27
- An analog amplifier (TIA; “Trans” Impedance ”AMP) 24 that amplifies an analog electric signal to a predetermined amplitude by the signal is provided.
- FIG. 3 shows a block diagram of the internal configuration of the conversion demodulator 25.
- the conversion demodulator 25 includes an ADC unit 201 that converts an analog electric signal into a digital signal, a dispersion estimation / compensation unit 202 that estimates and compensates for chromatic dispersion and polarization dispersion, and a carrier that extracts a clock from the digitally converted signal. And a QPSK demodulator 204 that demodulates the QPSK signal and generates an electrical signal (output signal) having the same waveform as the original signal.
- polarization dispersion is a phenomenon in which the reflection direction of light in a fiber is divided into a fast component and a slow component due to distortion of the optical fiber, and a difference in arrival time occurs between them, thereby widening the width of the signal component.
- the ADC unit 201 monitors the average amplitude of the input analog electrical signal and outputs the monitor value to the comparator 27.
- the dispersion compensation estimation / compensation unit 202 outputs the dispersion estimation result to the reference generation circuit 26.
- the carrier estimation unit 203 detects the phase state of the local light and the signal light of the dispersion-compensated signal and corrects the phase.
- the QPSK demodulator 204 demodulates the phase-corrected signal and restores the same data signal as the input signal in the optical transmitter.
- FIG. 4 shows a block diagram of the internal configuration of the amplitude control unit 102.
- the amplitude controller 102 receives the variance estimation result from the conversion demodulator 25 and generates a reference value (reference value), and receives the analog electrical signal amplitude monitor value from the conversion demodulator 25 to generate a reference.
- a comparator (COMP) 27 that compares the reference value input from the circuit 26 and outputs a gain control signal to the analog amplifier 24 is provided.
- the reference generation circuit 26 includes an input unit 104 serving as an interface for inputting the variance estimation value output from the variance estimation / compensation unit 202, and an operation for calculating an optimal reference value based on the variance estimation value. And an output unit 106 serving as an interface for outputting the reference value to the comparator 27.
- the above configuration is an example, and other device configurations may be used.
- the comparator 27 receives an input unit 107 serving as an interface for inputting the reference value output from the reference generation circuit 26 and the amplitude monitor value output from the ADC unit, and the reference value and the amplitude monitor value.
- a comparison unit 108 for comparison, and an output unit 109 serving as an interface for outputting a gain control signal based on the result of comparing the reference value and the amplitude monitor value to the analog amplifier 24 are provided.
- the above configuration is an example, and other device configurations may be used.
- the optical transmitter 1 performs DP-QPSK modulation of the CW light from the LD 11 using the input electrical signal, and sends it to the transmission line.
- the optical receiver 2 inputs the DP-QPSK optical signal received from the transmission path and the local light generated by the local light generator 21 to the 90-degree hybrid circuit 22.
- the 90-degree hybrid circuit 22 separates the input optical signal and local light into four parts, adjusts the polarization and phase so that the DP-QPSK signal can be demodulated, and combines the optical signal and local light.
- the 90-degree hybrid circuit 22 inputs the combined light to the four PDs 23, and converts the phase modulation into amplitude modulation by causing the signal light and the local light to interfere with each other to generate an analog electric signal. Since this analog electric signal is weak, it is amplified to a predetermined amplitude by the analog amplifier 24. At this time, the comparator 27 uses the control signal to adjust the gain of the analog amplifier 24 so that the signal amplitude at the input of the ADC unit 201 in the conversion demodulator 25 is constant.
- FIG. 5 is a flowchart showing processing of the control method of the communication system 100.
- the optical receiver 2 receives the optical signal transmitted by the optical transmitter 1.
- the optical receiver calculates a chromatic dispersion estimated value of the received optical signal (S100).
- the optical receiver 2 compares the estimated chromatic dispersion value with a predetermined reference value and determines the magnitude (S101).
- the optical receiver 2 determines that the chromatic dispersion value is larger than the reference value (S101: yes).
- the optical receiver 2 sets the reference value to be smaller (S102).
- the optical receiver 2 controls the amplitude of the analog electric signal to be small based on the reference value (S103).
- the optical receiver 2 determines that the dispersion value is smaller than the reference value (S101: no)
- the optical receiver 2 sets the reference value to be larger (S104).
- the optical receiver 2 largely controls the amplitude of the analog electric signal based on the reference value (S105).
- FIG. 6 is a sequence diagram showing processing of each unit of the optical receiver 2.
- the reference generation circuit 26 As an initial state, the reference generation circuit 26 generates a reference value (reference value) when the estimated chromatic dispersion value is maximum, that is, a minimum reference value, and the comparator 27 uses the reference value to increase the gain of the analog amplifier 24.
- a reference value reference value
- the comparator 27 controls the gain of the TIA 24 to be small with the minimum reference value, the input amplitude to the ADC unit 201 does not exceed the dynamic range.
- the analog amplifier 24 amplifies the analog electric signal and inputs it to the conversion demodulator 25.
- the conversion demodulator 25 samples the input analog electric signal in the ADC unit 201 and converts the amplitude information into a digital signal.
- the ADC unit 201 monitors the amplitude of the analog electric signal and outputs a monitor value to the comparator 27.
- the ADC unit 201 performs sampling based on the waveform of the analog signal, converts the analog signal into a digital signal, and inputs the digital signal to the dispersion estimation / compensation unit 202.
- the dispersion estimation / compensation unit 202 estimates the chromatic dispersion value and the polarization dispersion value by numerical calculation, and compensates the chromatic dispersion based on the estimation result.
- the dispersion estimation / compensation unit 202 also outputs the chromatic dispersion estimated value to the reference generation circuit 26.
- the carrier estimation unit 203 detects the phase state of the local light and the signal light of the dispersion-compensated signal and corrects the phase.
- the QPSK demodulator 204 demodulates the phase-corrected signal and restores the original signal.
- the reference generation circuit 26 inputs the chromatic dispersion estimated value from the dispersion estimation / compensation unit 202 of the conversion demodulator 25 via the input unit 104.
- the input unit 104 outputs the chromatic dispersion estimated value to the calculation unit 105.
- the calculation unit calculates an optimum reference value corresponding to the chromatic dispersion value so that the input amplitude to the ADC unit 201 is optimized according to the chromatic dispersion estimated value from the dispersion estimation / compensation unit 202.
- a table may be referred to or calculation may be used.
- the calculation unit outputs the reference value to the comparator 27 via the output unit 106.
- the chromatic dispersion of the input signal is smaller than the predetermined reference value, the difference between the signal amplitude after dispersion compensation and the peak value of the signal amplitude of the electrical signal before dispersion compensation becomes small. Then, in order to increase the signal reception sensitivity, the input amplitude of the analog signal to the ADC unit 201 can be increased. Therefore, in the signal processing in the conversion demodulation unit 25 in the conversion demodulation unit, the TIA gain is increased within a range not exceeding the dynamic range, and the input amplitude to the ADC unit is optimized.
- the comparator 27 inputs the amplitude monitor value of the analog electric signal from the ADC unit 201 of the conversion demodulator 25 and the reference value from the reference generation circuit 26 via the input unit 107.
- the input unit 107 outputs the amplitude monitor value and the reference value to the comparison unit 108.
- the comparison unit 108 compares the amplitude monitor value with the reference value.
- the comparison unit 108 controls the gain of the analog amplifier 24 to be small when the amplitude monitor value is larger than the reference value via the output unit 109, and when the amplitude monitor value is smaller than the reference value, the gain of the analog amplifier 24 is Control to increase.
- the comparison unit 108 performs control so that the amplitude of the analog electric signal is reduced when the amplitude monitor value is larger than the reference value. Then, when the amplitude monitor value is smaller than the reference value, the comparison unit 108 performs control so that the amplitude of the analog electric signal is increased. However, the comparison unit 108 does not control the amplitude of the analog electric signal when the reference value is equal to the amplitude monitor value. By this control, the analog amplifier 24 adjusts the amplitude of the output analog signal to be the same as the reference value output by the reference generation circuit 26.
- the waveform of the analog electric signal output from the analog amplifier 24 is distorted due to the dispersion of the transmission path, the temporal distribution of the signal is broadened as the chromatic dispersion value is increased, and the variation in amplitude is increased due to the superposition of the signals. For this reason, when the chromatic dispersion of the transmission line is large, the peak value of the electric signal before dispersion compensation becomes larger than the signal amplitude after dispersion compensation. On the other hand, when the chromatic dispersion value of the transmission line is small, the temporal distribution of the signal is small and the variation in amplitude is also small. Therefore, the input amplitude of the analog signal to the ADC unit 201 may be increased within the allowable range of the ADC unit 201. it can.
- the method for controlling the amplitude of the analog electrical signal is such that when there is a first amplitude corresponding to the reference first chromatic dispersion value, the second chromatic dispersion value is greater than the first chromatic dispersion value.
- the second amplitude is controlled to be larger than the first amplitude
- the second chromatic dispersion value is larger than the first chromatic dispersion value
- the second amplitude is controlled to be smaller than the first amplitude. You can also do it.
- the chromatic dispersion value of the received signal estimated by the dispersion estimation / compensation unit 202 of the conversion demodulator 25 is input to the reference generation circuit, and the reference value is set according to the estimated chromatic dispersion value. It can be changed. Accordingly, the gain sensitivity of the analog amplifier 24 is controlled so that the input amplitude of the analog electric signal to the ADC unit 201 is optimized according to the chromatic dispersion value of the received signal, and the receiving sensitivity can be adjusted optimally.
- the DP-QPSK optical receiver 2 always adjusts the amplitude of the analog electric signal at the input of the ADC unit 201 of the optical receiver 2 to the optimum value according to the chromatic dispersion value of the transmission path of the optical signal, A decrease in signal reception sensitivity can be avoided.
- Embodiment 2 In the first embodiment, an example using the DP-QPSK communication method has been described. In the present embodiment, an example using a DP-BPSK (Dual Polarization-Binary Phase Shift Keying) method is shown.
- FIG. 7 shows a configuration example of an optical communication system 300 according to the present embodiment.
- FIG. 7 shows a configuration when the embodiment of the present invention is applied to the DP-BPSK modulation method.
- FIG. 7 shows an example of a DP-BPSK optical transmitter and a digital coherent receiver.
- the optical communication system 300 includes a DP-BPSK transmitter (optical transmitter) 3 and a digital coherent DP-BPSK receiver (optical receiver) 4.
- FIG. 8 is a diagram showing the configuration of the optical transmitter 3.
- the optical transmitter 3 includes a circuit for generating and transmitting a DP-BPSK signal.
- the optical transmitter 3 includes an LD (Laser Diode) 31 that generates CW (Continuous Wave) light serving as a light source of signal light, and DP-BPSK CW light of the LD 31 based on an input electric signal (input signal). And a DP-BPSK modulator 32 for modulation.
- LD Laser Diode
- CW Continuous Wave
- DP-BPSK modulator 32 for modulation.
- the DP-BPSK modulator 32 divides the CW light into two, BPSK modulation is performed on each of the two, and the polarization planes are orthogonalized at 90 degrees and combined to generate a polarization multiplexed signal.
- the optical transmitter 3 describes the configuration of a general DP-BPSK transmitter.
- FIG. 9 is a diagram showing the configuration of the optical receiver 4.
- the optical receiver 4 receives an optical signal, interferes with local light, converts the optical signal into an electrical signal, converts the analog electrical signal input from the photoelectric conversion unit 301 into a digital signal, A conversion demodulator 45 that performs chromatic dispersion compensation and DP-BPSK signal demodulation by processing, and an amplitude controller 302 are provided.
- the photoelectric conversion unit 301 includes a local light generation unit (LO; Local Oscillator) 41 that generates local light, a 90-degree hybrid circuit 42 that inputs and interferes with the received DP-BPSK signal and local light from the LO 41, Coherent detection of the optical signal interfered by the 90-degree hybrid circuit 42 and conversion into an analog electrical signal 43 (Photo Diode) 43, and an analog electrical signal from the PD 43 are input and gain control from a comparator (COMP) 47
- An analog amplifier (TIA; “Trans” Impedance ”AMP) 44 that amplifies an analog electric signal to a predetermined amplitude by the signal is provided.
- FIG. 9 shows a block diagram of the internal configuration of the conversion demodulator 45.
- the conversion demodulator 45 includes an ADC 401 that converts an analog electric signal into a digital signal, a dispersion estimation / compensation unit 402 that estimates and compensates for chromatic dispersion and polarization dispersion, and extracts a carrier from the digitally converted signal and outputs a clock. And a BPSK demodulator 404 that demodulates the BPSK signal and generates an electric signal (output signal) having the same waveform as the original signal.
- the ADC unit 401 monitors the average amplitude of the input analog electric signal and outputs the monitor value to the comparator 47.
- the dispersion estimation / compensation unit 402 outputs the dispersion estimation result to the reference generation circuit 46.
- the carrier estimation unit 403 detects the phase state of the local light and the signal light of the dispersion compensated signal, and corrects the phase.
- the BPSK demodulator 404 demodulates the phase-corrected signal and restores it to an output signal having the same waveform as the original signal.
- FIG. 10 shows a block diagram of the internal configuration of the amplitude control unit 302.
- the amplitude control unit 302 receives a chromatic dispersion estimation result from the conversion demodulation unit 45 and generates a reference value (reference value), and receives an amplitude monitor value of the analog electric signal from the conversion demodulation unit 45 and generates a reference.
- a comparator (COMP) 47 that compares the reference value input from the circuit 46 and outputs a gain control signal to the analog amplifier 44 is provided.
- COMP comparator
- the reference generation circuit 46 calculates an optimum reference value based on the chromatic dispersion estimated value, and an input unit 304 serving as an interface for inputting the chromatic dispersion estimated value output from the dispersion estimating / compensating unit 402. And an output unit 306 serving as an interface for outputting the reference value to the comparator 47.
- an input unit 304 serving as an interface for inputting the chromatic dispersion estimated value output from the dispersion estimating / compensating unit 402.
- an output unit 306 serving as an interface for outputting the reference value to the comparator 47.
- the comparator 47 includes an input unit 307 serving as an interface for inputting the reference value output from the reference generation circuit 46 and the amplitude monitor value output from the ADC unit, and the reference value and the amplitude monitor value.
- a comparison unit 308 for comparison and an output unit 309 serving as an interface for outputting a gain control signal based on the result of comparing the reference value and the amplitude monitor value to the analog amplifier 44 are provided.
- the above configuration is an example, and other device configurations may be used.
- the optical transmitter 3 performs DP-BPSK modulation of the CW light from the LD 31 using the input electrical signal and sends it to the transmission line.
- the optical receiver 4 inputs the DP-BPSK optical signal input from the transmission path and the local light generated by the local light generator 41 to the 90-degree hybrid circuit 42.
- the 90-degree hybrid circuit 42 divides the input optical signal and local light into two, respectively, adjusts the polarization and phase so that the DP-BPSK signal can be demodulated, and combines the optical signal and local light.
- the 90-degree hybrid circuit 42 inputs the combined light to the two PDs 43, converts the phase modulation into amplitude modulation by causing the signal light and the local light to interfere, and generates an analog electric signal. Since this analog electric signal is weak, it is amplified to a predetermined amplitude by the analog amplifier 44. At this time, the comparator 47 uses the control signal to adjust the gain of the analog amplifier 44 so that the signal amplitude at the input of the ADC unit 401 in the conversion demodulator 45 is constant.
- FIG. 11 is a flowchart showing processing of the communication method of the communication system 300.
- the optical receiver 4 receives the optical signal transmitted by the optical transmitter 3.
- the optical receiver calculates a chromatic dispersion estimated value of the received optical signal (S200).
- the optical receiver 4 compares the estimated chromatic dispersion value with a predetermined reference value and determines the magnitude (S201).
- the optical receiver 4 determines that the dispersion value is larger than the reference value (S201: yes).
- the optical receiver 4 sets the reference value to be smaller (S202).
- the optical receiver 4 controls the amplitude of the analog electric signal to be small based on the reference value (S203).
- the optical receiver 4 determines that the dispersion value is smaller than the reference value (S201: no)
- the optical receiver 4 sets the reference value to be larger (S204).
- the optical receiver 4 largely controls the amplitude of the analog electric signal based on the reference value (S205).
- the reference generation circuit 46 As an initial state, the reference generation circuit 46 generates a reference value (reference value) when the estimated chromatic dispersion value is maximum, that is, a minimum reference value, and the comparator 47 sets the gain of the analog amplifier 44 using this reference value. To do. When the chromatic dispersion of the input signal is maximum, the peak value of the signal amplitude is maximum. Since the comparator 47 controls the gain of the TIA 44 to be small with the minimum reference value, the input amplitude to the ADC unit 401 does not exceed the dynamic range.
- a reference value reference value
- the analog amplifier 44 amplifies the analog electric signal and inputs it to the conversion demodulator 45.
- the conversion demodulator 45 samples the input analog electric signal in the ADC unit 401 and converts the amplitude information into a digital signal.
- the ADC unit 401 monitors the amplitude of the electric signal and outputs a monitor value to the comparator 47.
- the ADC unit 401 performs sampling based on the waveform of the analog signal, converts the analog signal into a digital signal, and inputs the digital signal to the dispersion estimation / compensation unit 402.
- the dispersion estimation / compensation unit 402 estimates the chromatic dispersion value and the polarization dispersion value by numerical calculation, and compensates the dispersion based on the estimation result.
- the dispersion estimation / compensation unit 402 also outputs the chromatic dispersion estimated value to the reference generation circuit 46.
- the carrier estimation unit 403 detects the phase state of the local light and the signal light of the dispersion compensated signal, and corrects the phase.
- the BPSK demodulator 404 demodulates the phase-corrected signal and restores the original signal.
- the reference generation circuit 46 inputs the chromatic dispersion estimated value from the dispersion estimating / compensating unit 402 of the conversion demodulating unit 45 via the input unit 304.
- the input unit 304 outputs the chromatic dispersion estimated value to the calculation unit 305.
- the computing unit calculates an optimal reference value corresponding to the chromatic dispersion value so that the input amplitude to the ADC unit 301 is optimized according to the chromatic dispersion estimated value from the dispersion estimating / compensating unit 402.
- a table may be referred to or calculation may be used.
- the calculation unit outputs the reference value to the comparator 47 via the output unit 306.
- the chromatic dispersion of the input signal is smaller than the predetermined reference value, the difference between the signal amplitude after dispersion compensation and the peak value of the signal amplitude of the electrical signal before dispersion compensation becomes small. Then, in order to increase the signal reception sensitivity, the input amplitude of the analog signal to the ADC unit 301 can be increased. Therefore, in the signal processing in the conversion demodulation unit 45 in the conversion demodulation unit, the TIA gain is increased within a range not exceeding the dynamic range, and the input amplitude to the ADC unit is optimized.
- the comparator 47 receives the analog electrical signal amplitude monitor value from the ADC unit 301 of the conversion demodulation unit 45 and the reference value from the reference generation circuit 46 via the input unit 307.
- the input unit 307 outputs the amplitude monitor value and the reference value to the comparison unit 308.
- the comparison unit 308 compares the amplitude monitor value with the reference value.
- the comparison unit 308 controls the gain of the analog amplifier 24 to be small when the amplitude monitor value is larger than the reference value via the output unit 309, and when the amplitude monitor value is smaller than the reference value, the gain of the analog amplifier 24 is Control to increase.
- the comparison unit 308 performs control so that the amplitude of the analog electric signal becomes smaller when the amplitude monitor value is larger than the reference value. Then, the comparison unit 308 controls the amplitude of the analog electric signal to be increased when the amplitude monitor value is smaller than the reference value. However, the comparison unit 308 does not control the amplitude of the analog electrical signal when it is equal to the reference value and the amplitude monitor value. By this control, the analog amplifier 44 adjusts the amplitude of the output analog signal to be the same as the reference value output by the reference generation circuit 46.
- the analog electric signal output from the analog amplifier 44 is distorted in waveform due to dispersion in the transmission path, the time distribution of the signal is broadened with an increase in chromatic dispersion value, and the variation in amplitude becomes large due to signal superposition. For this reason, when the chromatic dispersion of the transmission line is large, the peak value of the electric signal before dispersion compensation becomes larger than the signal amplitude after dispersion compensation. On the other hand, when the chromatic dispersion value of the transmission path is small, the temporal distribution of the signal is small and the amplitude variation is also small. Therefore, the input amplitude of the analog signal to the ADC unit 401 may be increased within the allowable range of the ADC unit 401. it can.
- the method for controlling the amplitude of the analog electrical signal is such that when there is a first amplitude corresponding to the reference first chromatic dispersion value, the second chromatic dispersion value is greater than the first chromatic dispersion value.
- the second amplitude is controlled to be larger than the first amplitude
- the second chromatic dispersion value is larger than the first chromatic dispersion value
- the second amplitude is controlled to be smaller than the first amplitude. You can also do it.
- the chromatic dispersion value of the received signal estimated by the dispersion estimation / compensation unit 402 of the conversion demodulator 45 is input to the reference generation circuit, and the reference value is set according to the estimated chromatic dispersion value. It can be changed. As a result, the gain of the analog amplifier 44 is controlled so that the input amplitude to the ADC unit 401 is optimized according to the chromatic dispersion value of the received signal, and the receiving sensitivity can be optimally adjusted.
- the DP-BPSK optical receiver 2 always adjusts the amplitude of the analog electric signal at the input of the ADC unit 401 of the optical receiver 4 to an optimum value according to the chromatic dispersion value of the transmission path of the optical signal, A decrease in signal reception sensitivity can be avoided.
- optical communication method described above may be realized using a semiconductor processing apparatus including an ASIC (Application Specific Integrated Circuit).
- ASIC Application Specific Integrated Circuit
- These processes may be realized by causing a computer system including at least one processor (eg, a microprocessor, MPU, DSP (Digital Signal Processor)) to execute a program.
- processor eg, a microprocessor, MPU, DSP (Digital Signal Processor)
- one or a plurality of programs including an instruction group for causing the computer system to perform an algorithm related to the transmission signal processing or the reception signal processing may be created, and the programs may be supplied to the computer.
- Non-transitory computer readable media include various types of tangible storage media (tangible storage medium).
- non-transitory computer-readable media examples include magnetic recording media (eg flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg magneto-optical discs), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable ROM), flash ROM, RAM (random access memory)) are included.
- the program may also be supplied to the computer by various types of temporary computer-readable media.
- Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves.
- the temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.
- quadrature amplitude modulation Quadrature (Quadrature (Amplitude ⁇ Modulation: QAM), orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplex: OFDM), and other digital communication methods may be used.
- QAM Quadrature amplitude modulation
- OFDM Orthogonal Frequency Division Multiplex
- a communication system comprising: an optical transmitter that inputs an input signal, modulates and transmits an optical signal; and an optical receiver that receives the optical signal and demodulates it to an output signal,
- the optical receiver includes a photoelectric conversion unit that converts the optical signal into an analog electric signal, a conversion demodulation unit that converts the analog electric signal into a digital signal and demodulates the output signal, and an amplitude of the analog electric signal.
- Amplitude control means for controlling, The amplitude control means controls the amplitude of the analog electric signal according to the chromatic dispersion of the optical signal. Communications system.
- the amplitude control means controls the amplitude of the analog electric signal to be smaller as the wavelength dispersion of the optical signal is larger.
- the communication system according to attachment 1. (Appendix 3)
- the photoelectric conversion means includes an amplifier that amplifies the analog electric signal input to the conversion demodulation means.
- the amplitude control means estimates a chromatic dispersion value of the optical signal and determines a reference value for controlling a gain of the amplifier based on the estimated chromatic dispersion value;
- Photoelectric conversion means for converting an optical signal into an analog electrical signal; conversion demodulation means for converting the analog electrical signal into a digital signal and demodulating it into an output signal; and amplitude control means for controlling the amplitude of the analog electrical signal .
- the amplitude control means controls the amplitude of the analog electric signal according to the chromatic dispersion of the optical signal.
- Optical receiver (Appendix 5) The amplitude control means controls the amplitude of the analog electric signal to be smaller as the wavelength dispersion of the optical signal is larger.
- the optical receiver according to appendix 4.
- the photoelectric conversion means includes an amplifier that amplifies the analog electric signal input to the conversion demodulation means.
- the amplitude control means estimates a chromatic dispersion value of the optical signal and determines a reference value for controlling a gain of the amplifier based on the estimated chromatic dispersion value;
- the optical receiver according to appendix 4 or 5.
- Appendix 7 A method of controlling an optical receiver, wherein the optical receiver is configured to convert an optical signal into an analog electrical signal, convert the analog electrical signal into a digital signal, and demodulate the output signal.
- the control method comprises controlling the amplitude of the analog electric signal according to chromatic dispersion of the optical signal, Control method of optical receiver.
- the controlling includes controlling the amplitude of the analog electric signal to be smaller as the chromatic dispersion of the optical signal is larger.
- the method of controlling an optical receiver according to appendix 7. The optical receiver includes an amplifier that amplifies the analog electric signal input to the conversion demodulation means, The controlling includes estimating a dispersion value of the optical signal and determining a reference value for controlling a gain of the amplifier based on the estimated chromatic dispersion value;
- the method for controlling an optical receiver according to appendix 7 or 8. (Appendix 10) A non-transitory computer readable medium for causing a computer to perform an optical receiver control method, The optical receiver is configured to convert an optical signal into an analog electrical signal, convert the analog electrical signal into a digital signal, and demodulate the output signal,
- the control method includes controlling the amplitude of the analog electric signal according to chromatic dispersion of the optical signal.
- a non-transitory computer readable medium The controlling includes controlling the amplitude of the analog electric signal to be smaller as the chromatic dispersion of the optical signal is larger.
- the optical receiver includes an amplifier that amplifies the analog electric signal input to the conversion demodulation means, The controlling includes estimating a chromatic dispersion value of the optical signal and determining a reference value for controlling the gain of the amplifier based on the estimated chromatic dispersion value.
- Optical Transmitter 2 Optical Receiver 3
- Optical Transmitter 4 Optical Receiver 11 LD (Laser Diode) 12 DP-QPSK modulator 21 Local light generator (LO) 22 90 degree hybrid circuit 23 PD (Photo Diode) 24 Analog Amplifier (TIA; Trans Impedance AMP) 25 Conversion demodulator (DSP) 26 Reference Generation Circuit 27 Comparator (COMP) 31 LD (Laser Diode) 32 DP-BPSK modulator 41 Local light generator (LO) 42 90 degree hybrid circuit 43 PD (Photo Diode) 44 Analog Amplifier (TIA; Trans Impedance AMP) 45 Conversion Demodulator (DSP) 46 Reference generation circuit 47 Comparator (COMP) 100 optical communication system 101 photoelectric conversion unit 102 amplitude control unit 104 input unit 105 arithmetic unit 106 output unit 107 input unit 108 comparison unit 109 output unit 201 ADC unit 202 dispersion estimation / compensation unit 203 carrier estimation unit 204 QPS
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Abstract
Description
本発明は、波長分散に応じて光受信器の受信感度を制御する光通信システムを提供することを目的とする。
図12は、本発明の関連する技術である通信システム500を示している。図12のデジタルコヒーレント受信器560は、光送信器550が送信した信号光を受信し、ローカル光を90度ハイブリッド回路522で干渉させ、PD(Photo Diode)523においてコヒーレント検波によりアナログ電気信号に変換し、アナログ増幅器524において信号振幅を一定にしてDSP(Digital Signal Processor)525のADC(Analog/Digital Converter)部501に入力している。
図1に本実施の形態による光通信システム100の構成例を示す。図1は、DP-QPSK(Dual Polarization-Quadrature Phase Shift Keying)方式の光送信器とデジタルコヒーレント方式の光受信器を示している。光通信システム100は、DP-QPSK送信機(光送信器)1とデジタルコヒーレントDP-QPSK受信器(光受信器)2とを備える。
次に図2と図3を参照し、本実施の形態の通信システム100の処理について説明する。光送信器1は入力した電気信号を用いてLD11からCW光をDP-QPSK変調し、伝送路へ送出する。光受信器2は、伝送路から受信したDP-QPSK光信号とローカル光生成部21で生成したローカル光を90度ハイブリッド回路22に入力する。90度ハイブリッド回路22は、入力した光信号とローカル光をそれぞれ4つに分離し、DP-QPSK信号を復調できるように偏波と位相を調整して光信号とローカル光を合波する。
アナログ増幅器24は、アナログ電気信号を増幅し、変換復調部25へ入力する。
本実施の形態によると、変換復調部25の分散推定・補償部202で推定した受信信号の波長分散値をリファレンス生成回路に入力し、推定された波長分散値に応じて参照値を変化させる事ができる。これにより受信信号の波長分散値に応じてADC部201へのアナログ電気信号の入力振幅が最適となるようにアナログ増幅器24の利得制御を行い、受信感度を最適に調整することができる。
実施の形態1は、DP-QPSKの通信方式による例を示した。本実施の形態は、DP-BPSK(Dual Polarization-Binary Phase Shift Keying)方式による例を示す。図7に本実施の形態による光通信システム300の構成例を示す。図7はDP-BPSK変調方式に本発明の実施の形態を適用した場合の構成を示している。図7にはDP-BPSK方式の光送信器とデジタルコヒーレント受信器を例として記載している。光通信システム300は、DP-BPSK送信器(光送信器)3とデジタルコヒーレントDP-BPSK受信器(光受信器)4とを備える。
効果の説明
本実施の形態によると、変換復調部45の分散推定・補償部402で推定した受信信号の波長分散値をリファレンス生成回路に入力し、推定された波長分散値に応じて参照値を変化させる事ができる。これにより受信信号の波長分散値に応じてADC部401への入力振幅が最適となるようにアナログ増幅器44の利得制御を行い、受信感度を最適に調整することができる。
上記で説明した光通信方法は、ASIC(Application Specific Integrated Circuit)を含む半導体処理装置を用いて実現されてもよい。また、これらの処理は、少なくとも1つのプロセッサ(e.g. マイクロプロセッサ、MPU、DSP(Digital Signal Processor))を含むコンピュータシステムにプログラムを実行させることによって実現されてもよい。具体的には、これらの送信信号処理又は受信信号処理に関するアルゴリズムをコンピュータシステムに行わせるための命令群を含む1又は複数のプログラムを作成し、当該プログラムをコンピュータに供給すればよい。
(付記1)
入力信号を入力し、光信号に変調して送信する光送信器と、前記光信号を受信して出力信号に復調する光受信器とを備える通信システムであって、
前記光受信器は、前記光信号をアナログ電気信号に変換する光電変換手段と、前記アナログ電気信号をデジタル信号に変換して前記出力信号に復調する変換復調手段と、前記アナログ電気信号の振幅を制御する振幅制御手段とを備え、
前記振幅制御手段は、前記光信号の波長分散に応じて前記アナログ電気信号の振幅を制御する、
通信システム。
(付記2)
前記振幅制御手段は、前記光信号の波長分散が大きいほど前記アナログ電気信号の振幅を小さくするよう制御する、
付記1に記載の通信システム。
(付記3)
前記光電変換手段は、前記変換復調手段に入力される前記アナログ電気信号を増幅する増幅器を備え、
前記振幅制御手段は、前記光信号の波長分散値を推定し、推定された波長分散値に基づいて前記増幅器の利得を制御するための参照値を決定する、
付記1又は2に記載の通信システム。
(付記4)
光信号をアナログ電気信号に変換する光電変換手段と、前記アナログ電気信号をデジタル信号に変換して出力信号に復調する変換復調手段と、前記アナログ電気信号の振幅を制御する振幅制御手段とを備え、
前記振幅制御手段は、前記光信号の波長分散に応じて前記アナログ電気信号の振幅を制御する、
光受信器。
(付記5)
前記振幅制御手段は、前記光信号の波長分散が大きいほど前記アナログ電気信号の振幅を小さくするよう制御する、
付記4に記載の光受信器。
(付記6)
前記光電変換手段は、前記変換復調手段に入力される前記アナログ電気信号を増幅する増幅器を備え、
前記振幅制御手段は、前記光信号の波長分散値を推定し、推定された波長分散値に基づいて前記増幅器の利得を制御するための参照値を決定する、
付記4又は5に記載の光受信器。
(付記7)
光受信機の制御方法であって
光受信器は、光信号をアナログ電気信号に変換し、前記アナログ電気信号をデジタル信号に変換して出力信号に復調するよう構成され、
前記制御方法は、前記光信号の波長分散に応じて前記アナログ電気信号の振幅を制御することを備える、
光受信器の制御方法。
(付記8)
前記制御することは、前記光信号の波長分散が大きいほど前記アナログ電気信号の振幅を小さくするよう制御することを含む、
付記7に記載の光受信器の制御方法。
(付記9)
前記光受信器は、変換復調手段に入力される前記アナログ電気信号を増幅する増幅器を備え、
前記制御することは、前記光信号の分散値を推定し、推定された波長分散値に基づいて前記増幅器の利得を制御するための参照値を決定することを含む、
付記7又は8に記載の光受信器の制御方法。
(付記10)
光受信機の制御方法をコンピュータに行わせるための非一時的なコンピュータ可読媒体であって、
光受信器は、光信号をアナログ電気信号に変換し、前記アナログ電気信号をデジタル信号に変換して出力信号に復調するよう構成され、
前記制御方法は、前記光信号の波長分散に応じて前記アナログ電気信号の振幅を制御することを含む、
非一時的なコンピュータ可読媒体。
(付記11)
前記制御することは、前記光信号の波長分散が大きいほど前記アナログ電気信号の振幅を小さくするよう制御することを含む、
付記10に記載の非一時的なコンピュータ可読媒体。
(付記12)
前記光受信器は、変換復調手段に入力される前記アナログ電気信号を増幅する増幅器を備え、
前記制御することは、前記光信号の波長分散値を推定し、推定された波長分散値に基づいて前記増幅器の利得を制御するための参照値を決定することを含む、
付記10又は11に記載の非一時的なコンピュータ可読媒体。
2 光受信器
3 光送信器
4 光受信器
11 LD(Laser Diode)
12 DP-QPSK変調器
21 ローカル光生成部(LO; Local Oscillator)
22 90度ハイブリッド回路
23 PD(Photo Diode)
24 アナログ増幅器(TIA; Trans Impedance AMP)
25 変換復調部(DSP)
26 リファレンス生成回路
27 比較器(COMP; Comparator)
31 LD(Laser Diode)
32 DP-BPSK変調器
41 ローカル光生成部(LO; Local Oscillator)
42 90度ハイブリッド回路
43 PD(Photo Diode)
44 アナログ増幅器(TIA; Trans Impedance AMP)
45 変換復調部(DSP)
46 リファレンス生成回路
47 比較器(COMP; Comparator)
100 光通信システム
101 光電変換部
102 振幅制御部
104 入力部
105 演算部
106 出力部
107 入力部
108 比較部
109 出力部
201 ADC部
202 分散推定・補償部
203 キャリア推定部
204 QPSK復調部
300 光通信システム
301 光電変換部
302 振幅制御部
304 入力部
305 演算部
306 出力部
307 入力部
308 比較部
309 出力部
401 ADC部
402 分散推定・補償部
403 キャリア推定部
404 BPSK復調部
500 光通信システム
501 ADC部
521 ローカル光生成部(LO; Local Oscillator)
522 90度ハイブリッド回路
523 PD(Photo Diode)
524 アナログ増幅器(TIA; Trans Impedance AMP)
525 変換復調部(DSP)
526 リファレンス生成回路
527 比較器(COMP; Comparator)
550 光送信器
560 光受信器
Claims (10)
- 入力信号を入力し、光信号に変調して送信する光送信器と、前記光信号を受信して出力信号に復調する光受信器とを備え、
前記光受信器は、前記光信号をアナログ電気信号に変換する光電変換手段と、前記アナログ電気信号をデジタル信号に変換して前記出力信号に復調する変換復調手段と、前記アナログ電気信号の振幅を制御する振幅制御手段とを備え、
前記振幅制御手段は、前記光信号の波長分散に応じて前記アナログ電気信号の振幅を制御する、
通信システム。 - 前記振幅制御手段は、前記光信号の波長分散が大きいほど前記アナログ電気信号の振幅を小さくするよう制御する、
請求項1に記載の通信システム。 - 前記光電変換手段は、前記変換復調手段に入力される前記アナログ電気信号を増幅する増幅器を備え、
前記振幅制御手段は、前記光信号の波長分散値を推定し、推定された波長分散値に基づいて前記増幅器の利得を制御するための参照値を決定する、
請求項1又は2に記載の通信システム。 - 光信号をアナログ電気信号に変換する光電変換手段と、前記アナログ電気信号をデジタル信号に変換して出力信号に復調する変換復調手段と、前記アナログ電気信号の振幅を制御する振幅制御手段とを備え、
前記振幅制御手段は、前記光信号の波長分散に応じて前記アナログ電気信号の振幅を制御する、
光受信器。 - 前記振幅制御手段は、前記光信号の波長分散が大きいほど前記アナログ電気信号の振幅を小さくするよう制御する、
請求項4に記載の光受信器。 - 前記光電変換手段は、前記変換復調手段に入力される前記アナログ電気信号を増幅する増幅器を備え、
前記振幅制御手段は、前記光信号の波長分散値を推定し、推定された波長分散値に基づいて前記増幅器の利得を制御するための参照値を決定する、
請求項4又は5に記載の光受信器。 - 光受信器は、光信号をアナログ電気信号に変換し、前記アナログ電気信号をデジタル信号に変換して出力信号に復調するよう構成され、
前記制御方法は、前記光信号の波長分散に応じて前記アナログ電気信号の振幅を制御することを備える、
光受信器の制御方法。 - 前記制御することは、前記光信号の波長分散が大きいほど前記アナログ電気信号の振幅を小さくするよう制御することを含む、
請求項7に記載の光受信器の制御方法。 - 前記光受信器は、変換復調手段に入力される前記アナログ電気信号を増幅する増幅器を備え、
前記制御することは、前記光信号の波長分散値を推定し、推定された波長分散値に基づいて前記増幅器の利得を制御するための参照値を決定することを含む、
請求項7又は8に記載の光受信器の制御方法。 - 光受信器は、光信号をアナログ電気信号に変換し、前記アナログ電気信号をデジタル信号に変換して出力信号に復調するよう構成され、
前記制御方法は、前記光信号の波長分散に応じて前記アナログ電気信号の振幅を制御することを含む、光受信機の制御方法をコンピュータに行わせるための非一時的なコンピュータ可読媒体。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
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US14/904,023 US10009102B2 (en) | 2013-07-11 | 2014-05-26 | Optical communication system, optical receiver, optical receiver control method, and non-transitory computer readable medium |
JP2015526140A JP6112202B2 (ja) | 2013-07-11 | 2014-05-26 | 光通信システム、光受信器、光受信器の制御方法及びプログラム |
EP14823778.7A EP3021501B1 (en) | 2013-07-11 | 2014-05-26 | Light communication system, light receiver, light receiver control method, and nontemporary computer readable medium |
US15/991,852 US10320483B2 (en) | 2013-07-11 | 2018-05-29 | Optical communication system, optical receiver, optical receiver control method, and non-transitory computer readable medium |
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US15/991,852 Continuation US10320483B2 (en) | 2013-07-11 | 2018-05-29 | Optical communication system, optical receiver, optical receiver control method, and non-transitory computer readable medium |
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JP2017005386A (ja) * | 2015-06-05 | 2017-01-05 | 日本電信電話株式会社 | 光受信装置及び光受信方法 |
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US10009102B2 (en) * | 2013-07-11 | 2018-06-26 | Nec Corporation | Optical communication system, optical receiver, optical receiver control method, and non-transitory computer readable medium |
CN107171745B (zh) * | 2017-03-24 | 2023-04-07 | 厦门优迅高速芯片有限公司 | 一种用于dp-qpsk接收机的高速adc的测试系统和方法 |
JP7057500B2 (ja) * | 2018-05-16 | 2022-04-20 | 日本電信電話株式会社 | 受信装置及び受信方法 |
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US10009102B2 (en) | 2018-06-26 |
US20160164610A1 (en) | 2016-06-09 |
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US20180351644A1 (en) | 2018-12-06 |
EP3021501B1 (en) | 2020-03-11 |
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