WO2003017534A2 - Crosstalk cancellation - Google Patents

Crosstalk cancellation Download PDF

Info

Publication number
WO2003017534A2
WO2003017534A2 PCT/IL2002/000651 IL0200651W WO03017534A2 WO 2003017534 A2 WO2003017534 A2 WO 2003017534A2 IL 0200651 W IL0200651 W IL 0200651W WO 03017534 A2 WO03017534 A2 WO 03017534A2
Authority
WO
WIPO (PCT)
Prior art keywords
crosstalk
optical
filter
receiver
transmitter
Prior art date
Application number
PCT/IL2002/000651
Other languages
French (fr)
Other versions
WO2003017534A3 (en
Inventor
Raanan Ivry
Original Assignee
Broadlight Ltd.
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 Broadlight Ltd. filed Critical Broadlight Ltd.
Priority to AU2002324313A priority Critical patent/AU2002324313A1/en
Publication of WO2003017534A2 publication Critical patent/WO2003017534A2/en
Publication of WO2003017534A3 publication Critical patent/WO2003017534A3/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/40—Transceivers
    • 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
    • H04B10/80—Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water
    • H04B10/85—Protection from unauthorised access, e.g. eavesdrop protection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems

Definitions

  • the present invention generally relates to optical transceivers. More specifically, the present invention relates to a device for crosstalk cancellation in optical transceivers.
  • a bi-directional optical transceiver which transmits and receives optical data, becomes a key component in optical links such as Passive Optical Networks (PON). Integration of the transmitter and receiver into one module reduces the cost of the system, of which the transceiver is one of the most expensive parts.
  • PON Passive Optical Networks
  • the crosstalk in optical transceivers can limit the performance of the receiver in that transceiver. In order to prevent performance degradation, or to improve the situation, a higher price must be paid. In the case of optical crosstalk, the price of a double filter must be paid. In the case of electrical crosstalk, a more expensive size and material design is needed.
  • the object of the invention is to have a new architecture for optical transceivers.
  • the invention will improve the receiver sensitivity by implementing new crosstalk cancellation techniques.
  • SNDR Signal to Noise and Distortion
  • the present invention provides a device useful for cancellation of crosstalk in an optical transceiver, integrating transmission of an output signal and reception of an input signal comprising: a tunable filter for cancelling the crosstalk component from the transmitter to the receiver; a delay element for closing the gap between the input signal and cancelled crosstalk component; and an adaptation circuit for adjusting to the changing characteristics of the device, such as the signal to noise and distortion ratio and the relative amounts of electrical and optical crosstalk, such that the crosstalk component from the transmitter to the receiver is more fully cancelled.
  • the tunable filter is a linear filter.
  • the adaptation circuit has a zero-forcing algorithm.
  • the adaptation circuit has a least mean squares algorithm.
  • the tunable filter is a non-linear filter.
  • the filter incorporates analog techniques.
  • the filter incorporates digital techniques.
  • the tunable filter is a combination of linear and nonlinear filters.
  • the crosstalk between the transmitter and the receiver is electrical crosstalk.
  • the crosstalk between the transmitter and the receiver is optical crosstalk.
  • Fig. 1 is a schematic block diagram of a general prior art optical transceiver, which consists of a bi-directional optical module and the electrical circuitry;
  • Fig. 2 is a schematic block diagram illustrating the implementation of crosstalk cancellation in an optical transceiver, constructed and operated in accordance with the principles of the present invention
  • Fig. 3 is a schematic block diagram illustrating the implementation of crosstalk cancellation in an optical transceiver using a linear type tunable filter, constructed and operated in accordance with the principles of the present invention.
  • Fig. 4 is a schematic block diagram illustrating the implementation of crosstalk cancellation in an optical transceiver using a non-linear type tunable filter, constructed and operated in accordance with the principles of the present invention.
  • fig. 1 is a schematic block diagram of a general prior art optical transceiver 100, which consists of a bi-directional optical module 110 and the electrical circuitry 120.
  • the crosstalk in optical transceivers can limit the performance of the receiver in that transceiver. In order to prevent performance degradation, or to improve the situation, a higher price must be paid. In the case of optical crosstalk, the price of a double filter must be paid.
  • Bi-directional module 110 comprises laser diode 112, Positive Intrinsic Negative (PIN) diode 114 and Wave Division Multiplex (WDM) filter 116 and/or beam splitter 118.
  • Laser diode 112 converts the electrical current, which contains the transmitted information, into optical power, which is coupled to the fiber.
  • PIN diode 114 converts the received optical power, which contains the received information, into electrical current.
  • the Avalanche Photo Diode (APD) can alternatively be used for more sensitive and more expensive receivers.
  • Beam splitter 118 directs the output optical power of laser diode 112 to the fiber, but part of the output power flows to PIN diode 114 or the APD alternative optical input. This part is the optical crosstalk.
  • the optical WDM filter 116 which reduces the optical crosstalk, can also be used for better performance.
  • the other part of the receiver shown in figure 1 is electrical circuitry 120.
  • the laser diode driver 122 which converts the transmitted data stream into current which drive laser diode 112.
  • the receive side 125 comprises a pre-amplifier 126, a limiter amplifier 127 and a clock data recovery circuit (CDR) 128.
  • Pre amplifier 126 is a low noise amplifier, usually a trans impedance amplifier that amplifies the low electrical current at the output of PIN diode 114.
  • Limiter amplifier 127 discriminates the noisy signal into a 2-level signal.
  • CDR 128 estimates the timing of the stream, and samples the data at the right points. Feedback methods, such as Phase Lock Loop (PLL) or feed forward methods can be used for CDR 128.
  • PLL Phase Lock Loop
  • the optical crosstalk attenuation is limited to less than 50dB while the electrical crosstalk attenuation is limited to less than lOOdB. That means that using an expensive and sensitive detector Avalanche Photo Diode (APD), will not improve the transceivers' performance because of the crosstalk.
  • APD Avalanche Photo Diode
  • FIG. 2 a schematic block diagram is shown illustrating the implementation of crosstalk cancellation 200 in an optical transceiver, constructed and operated in accordance with the principles of the present invention.
  • the gray blocks in fig. 2 implement the crosstalk cancellation. These blocks are the tunable filter 210, the delay element 220 and the adaptation circuit 230.
  • the received signal 255 consists of the wanted received signal 250 and the crosstalk (optical and electrical) components 257.
  • Crosstalk components 257 can be modeled as a transmitted data signal 240, which passes through filter 210, and which can have linear and nonlinear components, as detailed accordingly hereinbelow in fig.3 and fig. 4.
  • Tunable filter 210 can be of 2 basic types: a linear type; a nonlinear type; or a combination of linear and non linear.
  • a linear type tunable filter is a tapped delay line (FIR - Finite Impulse Response) with programmable or tunable coefficients.
  • FIG. 3 a schematic block diagram is shown, illustrating the implementation of crosstalk cancellation in an optical transceiver using a linear type tunable filter 300, constructed and operated in accordance with the principles of the present invention.
  • Adaptive filters are a subset of digital filters, which are a digital signal processing technique used to alter the characteristics of a signal.
  • the advantage of adaptive filters is that they can adjust to the changing characteristics of the system.
  • Linear filter 310 improves on the simple FIR delay line by allowing the system to choose a single optimal time-constant by minimizing the Mean Squared Error of the system.
  • the tapped delay line is an FIR filter, used in nearly all digital interference canceling applications due to its inherent stability.
  • the time delay taps 320 are scaled by weighting coefficients 330, and then summed 340 to form FIR linear filter 310.
  • the implementation can be digital or analog.
  • DAC Digital to Analog Converter
  • Nonlinear type tuned filter is described in figure 4.
  • Fig. 4 a schematic block diagram is shown, illustrating the implementation of crosstalk cancellation in an optical transceiver using a non-linear type tunable filter 400, constructed and operated in accordance with the principles of the present invention.
  • the data sequence determines the pulse-shape 457 to be subtracted from the received signal 450.
  • analog and digital techniques can be used.
  • the delay component in both implementations is used to ensure that precursor and post cursor bits will determine the signal to be cancelled.

Abstract

A device useful for cancellation of crosstalk in an optical transceiver, integrating transmission of an output signal and reception of an input signal comprising:a tunable filter for cancelling the crosstalk component from the transmitter to the receiver; a delay element for closing the gap between the input signal and cancelled crosstalk component; and an adaptation circuit for adjusting to the changing characteristics of the device, such as the signal to noise and distortion ratio and the relative amounts of electrical and optical crosstalk, such that the crosstalk component from the transmitter to the receiver is more fully cancelled.

Description

A DEVICE FOR CROSSTALK CANCELLATION IN OPTICAL TRANSCEIVERS
FIELD OF THE INVENTION
The present invention generally relates to optical transceivers. More specifically, the present invention relates to a device for crosstalk cancellation in optical transceivers.
BACKGROUND
A bi-directional optical transceiver, which transmits and receives optical data, becomes a key component in optical links such as Passive Optical Networks (PON). Integration of the transmitter and receiver into one module reduces the cost of the system, of which the transceiver is one of the most expensive parts.
However, integration has its own price. Optical and electrical crosstalk may reach the receiver, and degrade its performance. Reduction of crosstalk has been achieved using expensive techniques, such as optical filtering and electrical separation, which achieve high crosstalk attenuation.
The crosstalk in optical transceivers can limit the performance of the receiver in that transceiver. In order to prevent performance degradation, or to improve the situation, a higher price must be paid. In the case of optical crosstalk, the price of a double filter must be paid. In the case of electrical crosstalk, a more expensive size and material design is needed.
Therefore, there is a need to provide an optical transceiver that overcomes the disadvantages of prior art technology. SUMMARY OF THE INVENTION
The object of the invention is to have a new architecture for optical transceivers. The invention will improve the receiver sensitivity by implementing new crosstalk cancellation techniques.
It is another object of the present invention to provide better performance receivers. By improving the receiver sensitivity the invention enables longer distance optical communication and/or higher rate optical communication at lower cost.
It is a further object of the present invention to provide a new technique called crosstalk cancellation, which improves the receiver performance by improving the Signal to Noise and Distortion (SNDR).
The present invention provides a device useful for cancellation of crosstalk in an optical transceiver, integrating transmission of an output signal and reception of an input signal comprising: a tunable filter for cancelling the crosstalk component from the transmitter to the receiver; a delay element for closing the gap between the input signal and cancelled crosstalk component; and an adaptation circuit for adjusting to the changing characteristics of the device, such as the signal to noise and distortion ratio and the relative amounts of electrical and optical crosstalk, such that the crosstalk component from the transmitter to the receiver is more fully cancelled. In certain embodiments, the tunable filter is a linear filter. In such case, in certain embodiments the adaptation circuit has a zero-forcing algorithm. In other embodiments the adaptation circuit has a least mean squares algorithm.
In certain embodiments the tunable filter is a non-linear filter. In this case, in certain embodiments the filter incorporates analog techniques. In other embodiments the filter incorporates digital techniques.
In certain embodiments the tunable filter is a combination of linear and nonlinear filters.
In certain embodiments the crosstalk between the transmitter and the receiver is electrical crosstalk.
In certain embodiments the crosstalk between the transmitter and the receiver is optical crosstalk.
Other features and advantages of the invention will become apparent from the following drawings and description.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention with regard to the embodiments thereof, reference is made to the accompanying drawings, in which like numerals designate corresponding elements or sections throughout, and in which:
Fig. 1 is a schematic block diagram of a general prior art optical transceiver, which consists of a bi-directional optical module and the electrical circuitry;
Fig. 2 is a schematic block diagram illustrating the implementation of crosstalk cancellation in an optical transceiver, constructed and operated in accordance with the principles of the present invention; Fig. 3 is a schematic block diagram illustrating the implementation of crosstalk cancellation in an optical transceiver using a linear type tunable filter, constructed and operated in accordance with the principles of the present invention; and
Fig. 4 is a schematic block diagram illustrating the implementation of crosstalk cancellation in an optical transceiver using a non-linear type tunable filter, constructed and operated in accordance with the principles of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference is now made to fig. 1, which is a schematic block diagram of a general prior art optical transceiver 100, which consists of a bi-directional optical module 110 and the electrical circuitry 120. The crosstalk in optical transceivers can limit the performance of the receiver in that transceiver. In order to prevent performance degradation, or to improve the situation, a higher price must be paid. In the case of optical crosstalk, the price of a double filter must be paid. See, for example, "A 1.3/1.55μm BI-DIRECTIONAL TRANSCEIVER FOR ATM-PON ONU WITH - 40dBm FULL-DUPLEX SENSITIVITY USING A NOVEL DOUBLE-FILTER 1.55μm-PIN-PD", Yoshiki Kuhara, Hiromi Nakanishi, Takeshi Okada, Jiro Shinkai, Hitoshi Terauchi, ECOC 2000.
In the case of electrical crosstalk, a more expensive design in size and material is needed. See, for example, "AN ONU TRANSCEIVER MODULE USING PLC FOR 622Mbit/s-DOWNSTREAM ATM-PON SYSYTEM", H.Yanagisawa, A.Goto, R.Nomura, N.Kitamura, Y.Fukutomi, J.Yokoyama, M.Kunitsugu and K.Kaede, ECOC 2000. Bi-directional module 110 comprises laser diode 112, Positive Intrinsic Negative (PIN) diode 114 and Wave Division Multiplex (WDM) filter 116 and/or beam splitter 118. Laser diode 112 converts the electrical current, which contains the transmitted information, into optical power, which is coupled to the fiber.
PIN diode 114 converts the received optical power, which contains the received information, into electrical current. The Avalanche Photo Diode (APD) can alternatively be used for more sensitive and more expensive receivers.
Beam splitter 118 directs the output optical power of laser diode 112 to the fiber, but part of the output power flows to PIN diode 114 or the APD alternative optical input. This part is the optical crosstalk.
The optical WDM filter 116, which reduces the optical crosstalk, can also be used for better performance.
The other part of the receiver shown in figure 1 is electrical circuitry 120. In the transmit side 121, it is the laser diode driver 122, which converts the transmitted data stream into current which drive laser diode 112.
The receive side 125 comprises a pre-amplifier 126, a limiter amplifier 127 and a clock data recovery circuit (CDR) 128. Pre amplifier 126 is a low noise amplifier, usually a trans impedance amplifier that amplifies the low electrical current at the output of PIN diode 114. Limiter amplifier 127 discriminates the noisy signal into a 2-level signal. CDR 128 estimates the timing of the stream, and samples the data at the right points. Feedback methods, such as Phase Lock Loop (PLL) or feed forward methods can be used for CDR 128.
Since the electrical current of transmitted data 121 is much larger than the electrical current of received data 125, the transmitted current is induced to the receive circuitry. This induction happens via common electrical connections and via radiation. This induction is the electrical crosstalk.
The common methods that are used to attenuate the electrical crosstalk are careful design for maximum separation between the electrical output and electrical input. This makes the electrical component more expensive.
In all the known designs, the optical crosstalk attenuation is limited to less than 50dB while the electrical crosstalk attenuation is limited to less than lOOdB. That means that using an expensive and sensitive detector Avalanche Photo Diode (APD), will not improve the transceivers' performance because of the crosstalk.
Referring to Fig. 2, a schematic block diagram is shown illustrating the implementation of crosstalk cancellation 200 in an optical transceiver, constructed and operated in accordance with the principles of the present invention.
The gray blocks in fig. 2 implement the crosstalk cancellation. These blocks are the tunable filter 210, the delay element 220 and the adaptation circuit 230.
In reality, the received signal 255 consists of the wanted received signal 250 and the crosstalk (optical and electrical) components 257. Crosstalk components 257 can be modeled as a transmitted data signal 240, which passes through filter 210, and which can have linear and nonlinear components, as detailed accordingly hereinbelow in fig.3 and fig. 4.
In order to cancel the crosstalk, the transmitted data 245 is passed through tunable filter 210 and then subtracted 252 from wanted received signal 250. Tunable filter 210 can be of 2 basic types: a linear type; a nonlinear type; or a combination of linear and non linear.
A linear type tunable filter is a tapped delay line (FIR - Finite Impulse Response) with programmable or tunable coefficients.
Referring to Fig. 3, a schematic block diagram is shown, illustrating the implementation of crosstalk cancellation in an optical transceiver using a linear type tunable filter 300, constructed and operated in accordance with the principles of the present invention.
In the case of a linear filter 310 the adaptation can be performed using some known algorithms, like Zero-Forcing or Least Mean Squares (LMS) or others. See, for example, "The Theory and Practice of MODEM Design", John A.C. Bingham. Adaptive filters are a subset of digital filters, which are a digital signal processing technique used to alter the characteristics of a signal. The advantage of adaptive filters is that they can adjust to the changing characteristics of the system. Linear filter 310 improves on the simple FIR delay line by allowing the system to choose a single optimal time-constant by minimizing the Mean Squared Error of the system. The tapped delay line is an FIR filter, used in nearly all digital interference canceling applications due to its inherent stability. The time delay taps 320 are scaled by weighting coefficients 330, and then summed 340 to form FIR linear filter 310.
In figure 3 the implementation can be digital or analog. In the case of digital implementation a Digital to Analog Converter (DAC) is required at the filter's output.
Nonlinear type tuned filter is described in figure 4. Referring to Fig. 4, a schematic block diagram is shown, illustrating the implementation of crosstalk cancellation in an optical transceiver using a non-linear type tunable filter 400, constructed and operated in accordance with the principles of the present invention. In the case of non-linear filtering, the data sequence determines the pulse-shape 457 to be subtracted from the received signal 450. Also in this case, analog and digital techniques can be used.
The delay component in both implementations is used to ensure that precursor and post cursor bits will determine the signal to be cancelled.

Claims

CLAIMS:
1. A device useful for cancellation of crosstalk in an optical transceiver, integrating transmission of an output signal and reception of an input signal comprising: a tunable filter for cancelling the crosstalk component from the transmitter to the receiver; a delay element for closing the gap between the input signal and cancelled crosstalk component; and an adaptation circuit for adjusting to the changing characteristics of the device, such as the signal to noise and distortion ratio and the relative amounts of electrical and optical crosstalk, such that the crosstalk component from the transmitter to the receiver is more fully cancelled.
2. A device according to claim 1, wherein the tunable filter is a linear filter.
3. A device according to claim 2, wherein the adaptation circuit has a zero-forcing algorithm.
4. A device according to claim 2, wherein the adaptation circuit has a least mean squares algorithm.
5. A device according to claim 1, wherein the tunable filter is a non-linear filter.
6. A device according to claim 5, wherein said filter incorporates analog techniques.
7. A device according to claim 5, wherein said filter incorporates digital techniques.
8. A device according to claim 1, wherein the tunable filter is a combination of linear and nonlinear filters.
9. A device according to claim 1, wherein the crosstalk between the transmitter and the receiver is electrical crosstalk.
10. A device according to claim 1, wherein the crosstalk between the transmitter and the receiver is optical crosstalk.
PCT/IL2002/000651 2001-08-14 2002-08-08 Crosstalk cancellation WO2003017534A2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2002324313A AU2002324313A1 (en) 2001-08-14 2002-08-08 Crosstalk cancellation

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IL14489001A IL144890A0 (en) 2001-08-14 2001-08-14 A device for crosstalk cancellation in optical transceivers
IL144890 2001-08-14

Publications (2)

Publication Number Publication Date
WO2003017534A2 true WO2003017534A2 (en) 2003-02-27
WO2003017534A3 WO2003017534A3 (en) 2003-10-16

Family

ID=11075694

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IL2002/000651 WO2003017534A2 (en) 2001-08-14 2002-08-08 Crosstalk cancellation

Country Status (3)

Country Link
AU (1) AU2002324313A1 (en)
IL (1) IL144890A0 (en)
WO (1) WO2003017534A2 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005013517A2 (en) * 2003-07-30 2005-02-10 Denselight Semiconductors Pte Ltd. Optical transceiver with reduced optical cross-talk between transmitter and receiver
WO2008067776A1 (en) * 2006-12-07 2008-06-12 Huawei Technologies Co., Ltd. Method, device and signal processing system for remote crosstalk cancellation
US8300682B2 (en) 2006-12-07 2012-10-30 Huawei Technologies Co., Ltd. Signal processing system, filter device and signal processing method
WO2013098325A1 (en) * 2011-12-30 2013-07-04 Nokia Siemens Networks Oy Method and arrangement for signal transmission and compensation of back reflections in optical acces pon systems
US9071333B2 (en) 2006-12-15 2015-06-30 Huawei Technologies Co., Ltd. Device for canceling crosstalk, signal processing system and method for canceling crosstalk
US20150288418A1 (en) * 2012-12-26 2015-10-08 Huawei Technologies Co., Ltd. Crosstalk suppression method and apparatus

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5307405A (en) * 1992-09-25 1994-04-26 Qualcomm Incorporated Network echo canceller
US6198819B1 (en) * 1997-11-14 2001-03-06 Tellabs Operations, Inc. Echo canceller having improved non-linear processor
WO2001033730A1 (en) * 1999-11-05 2001-05-10 Infineon Technologies Ag Echo compensation device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5307405A (en) * 1992-09-25 1994-04-26 Qualcomm Incorporated Network echo canceller
US6198819B1 (en) * 1997-11-14 2001-03-06 Tellabs Operations, Inc. Echo canceller having improved non-linear processor
WO2001033730A1 (en) * 1999-11-05 2001-05-10 Infineon Technologies Ag Echo compensation device

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005013517A2 (en) * 2003-07-30 2005-02-10 Denselight Semiconductors Pte Ltd. Optical transceiver with reduced optical cross-talk between transmitter and receiver
WO2005013517A3 (en) * 2003-07-30 2005-04-28 Denselight Semiconductors Pte Optical transceiver with reduced optical cross-talk between transmitter and receiver
WO2008067776A1 (en) * 2006-12-07 2008-06-12 Huawei Technologies Co., Ltd. Method, device and signal processing system for remote crosstalk cancellation
US8254471B2 (en) 2006-12-07 2012-08-28 Huawei Technologies Co., Ltd. Far-end crosstalk canceling method and device, and signal processing system
US8295369B2 (en) 2006-12-07 2012-10-23 Huawei Technologies Co., Ltd. Far-end crosstalk canceling method and device, and signal processing system
US8300682B2 (en) 2006-12-07 2012-10-30 Huawei Technologies Co., Ltd. Signal processing system, filter device and signal processing method
US9787357B2 (en) 2006-12-07 2017-10-10 Huawei Technologies Co., Ltd. Far-end crosstalk canceling method and device
US8792568B2 (en) 2006-12-07 2014-07-29 Huawei Technologies Co., Ltd. Far-end crosstalk canceling method and device
US9071334B2 (en) 2006-12-07 2015-06-30 Huawei Technologies Co., Ltd. Far-end crosstalk canceling method and device
US9071333B2 (en) 2006-12-15 2015-06-30 Huawei Technologies Co., Ltd. Device for canceling crosstalk, signal processing system and method for canceling crosstalk
WO2013098325A1 (en) * 2011-12-30 2013-07-04 Nokia Siemens Networks Oy Method and arrangement for signal transmission and compensation of back reflections in optical acces pon systems
US9887735B2 (en) 2011-12-30 2018-02-06 Xieon Networks S.A.R.L. Method and arrangement for signal transmission and compensation of back reflections in optical access PON systems
US20150288418A1 (en) * 2012-12-26 2015-10-08 Huawei Technologies Co., Ltd. Crosstalk suppression method and apparatus
US9838074B2 (en) * 2012-12-26 2017-12-05 Huawei Technologies Co., Ltd. Crosstalk suppression method and apparatus

Also Published As

Publication number Publication date
AU2002324313A1 (en) 2003-03-03
WO2003017534A3 (en) 2003-10-16
IL144890A0 (en) 2002-06-30

Similar Documents

Publication Publication Date Title
US7224911B2 (en) Adaptive distortion compensation in optical fiber communication networks
US7471904B2 (en) Method and apparatus for electronic equalization in optical communication systems
US7574146B2 (en) Pattern-dependent error counts for use in correcting operational parameters in an optical receiver
EP1545030B1 (en) Optical channel equalisation
US6067180A (en) Equalization, pulse shaping and regeneration of optical signals
US6016374A (en) Optical fiber communications system with adaptive data equalizer
US9166703B2 (en) Equalizer for an optical transmission system
Nielsen et al. OFC 2004 workshop on optical and electronic mitigation of impairments
US7304543B2 (en) Burst-mode TIA (trans-impedance amplifier)
US7376352B2 (en) Chirp managed laser fiber optic system including an adaptive receiver
US6856724B2 (en) Compensation system for adaptive equalization of an optical signal
US6898379B2 (en) System and method for reducing interference in an optical data stream
KR20130071481A (en) Jitter reduction of electrical signals from limiting optical modules
WO2003017534A2 (en) Crosstalk cancellation
US7427939B2 (en) Parallel processed electronic dispersion control
US20060097777A1 (en) Architecture for transverse-form analog finite-impulse-response filter
US20020126355A1 (en) Dispersion compensation of higher-order optical signal distortion
JP5338593B2 (en) Distributed equalization circuit and optical transceiver
JP2000269892A (en) Optical receiver with waveform equalization function and method for controlling equalization of optical reception
US20050213995A1 (en) Low power and low jitter optical receiver for fiber optic communication link
JP2003503680A (en) Polarization mode dispersion detector
SU1672576A1 (en) Adaptive device for transmission and reception of information
EP0884867B1 (en) Equalisation, pulse shaping and regeneration of optical signals
US20020181040A1 (en) Decision circuit for high data rates as well as eye monitor, pseudoerror monitor, and system using the circuit
CA2196239C (en) Optical wavelength demultiplexer for a video passive optical network

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SI SK SL TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BY BZ CA CH CN CO CR CU CZ DE DM DZ EC EE ES FI GB GD GE GH HR HU ID IL IN IS JP KE KG KP KR LC LK LR LS LT LU LV MA MD MG MN MW MX MZ NO NZ OM PH PL PT RU SD SE SG SI SK SL TJ TM TN TR TZ UA UG US UZ VC VN YU ZA ZM

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): GH GM KE LS MW MZ SD SL SZ UG ZM ZW AM AZ BY KG KZ RU TJ TM AT BE BG CH CY CZ DK EE ES FI FR GB GR IE IT LU MC PT SE SK TR BF BJ CF CG CI GA GN GQ GW ML MR NE SN TD TG

Kind code of ref document: A2

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LU MC NL PT SE SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP