Including Compensation Patents (Class 398/158)
  • Patent number: 10826603
    Abstract: Optical receivers and methods for tuning an operating point of an optical resonator, such as a Fabry-Perot etalon are disclosed. A free-space optical signal is received at an optical receiver and directed towards at least one beam splitter. After passing through the beam splitter, the optical signal is reflected off a surface of the optical resonator. The reflected signal is detected and utilized to tune the operating point of the optical resonator.
    Type: Grant
    Filed: November 27, 2019
    Date of Patent: November 3, 2020
    Assignee: RAYTHEON COMPANY
    Inventors: Andrew Kowalevicz, Gary M. Graceffo, Benjamin P. Dolgin
  • Patent number: 10805003
    Abstract: An optical signal monitor, including: a storage that holds a threshold value set for each of determination areas having a bandwidth set in accordance with an average grid of dummy light; a measurement section that sequentially measures an optical intensity of an inputted wavelength-multiplexed optical signal with respect to each of measurement areas obtained by dividing the determination area into areas with a bandwidth sufficiently smaller than a grid width of a monitoring-target optical signal composing the wavelength-multiplexed optical signal, and output measured values; and a section that determines that dummy light corresponding to the determination area needs introducing if each of measured values in the determination area is smaller than a threshold value, and, determines that dummy light corresponding to the determination area does not need introducing if at least one of the measured values in the determination area is equal to or larger than the threshold value.
    Type: Grant
    Filed: June 13, 2019
    Date of Patent: October 13, 2020
    Assignee: NEC CORPORATION
    Inventor: Yoshirou Satou
  • Patent number: 10623094
    Abstract: In some embodiments, an apparatus includes an optical transceiver configured to be operatively coupled to a network. The optical transceiver includes a photo diode and a processor configured to be operatively coupled to the photo diode. The photo diode is configured to measure a receiver optical power (ROP) value and send the ROP value to the processor. The processor is configured to measure a bit error rate (BER) value of a digital modulated signal at an input port of the optical transceiver. The processor is also configured to determine an estimated optical signal noise ratio (OSNR) value at the input port of the optical transceiver based on the ROP value and the BER value. The processor is configured to send a signal indicating the estimated OSNR value such that a planned route is selected for sending data signals through within the optical transceiver based on the estimated OSNR value.
    Type: Grant
    Filed: January 29, 2019
    Date of Patent: April 14, 2020
    Assignee: Juniper Networks, Inc.
    Inventors: Qiang Wang, Massimiliano Salsi
  • Patent number: 10608737
    Abstract: A transmission device includes a memory, and a processor coupled to the memory and configured to acquire a polarization mode dispersion value of each of wavelengths of a polarization-multiplexed optical signal having a wavelength, multiply a mean value of the polarization mode dispersion values of the wavelengths by a prescribed ratio, to thereby calculate a maximum value of the polarization mode dispersion value that is temporally varied, and select a multi-level modulation scheme of the polarization-multiplexed optical signal based on an index value of transmission quality of the polarization-multiplexed optical signal depending on the maximum value.
    Type: Grant
    Filed: June 5, 2019
    Date of Patent: March 31, 2020
    Assignee: FUJITSU LIMITED
    Inventor: Hiroyuki Irie
  • Patent number: 10547408
    Abstract: In some embodiments, an apparatus includes a memory and a processor operatively coupled to the memory. The processor is configured to be operatively coupled to a first optical transponder and a second optical transponder. The processor is configured to receive, from the second optical transponder, a signal representing a skew value of an optical signal and a signal representing a bit-error-rate (BER) value of the optical signal. The skew value is associated with a skew between an in-phase component of the optical signal and a quadrature component of the optical signal. The processor is configured to determine, based on at least one of the skew value or the BER value, if a performance degradation of the first optical transponder satisfies a threshold. The processor is configured to send a control signal to the first optical transponder to adjust a pulse shaping or a data baud rate of the first optical transponder.
    Type: Grant
    Filed: May 3, 2018
    Date of Patent: January 28, 2020
    Assignee: Juniper Networks, Inc.
    Inventors: Xuan He, Qiang Wang, Yang Yue
  • Patent number: 10498457
    Abstract: It is possible to suppress carrier light with a simple configuration when modulating the carrier light to generate optical sideband components. An optical carrier-suppressed signal generator includes first splitting means used to split input carrier light into two light beams, an optical modulator which modulates one split carrier light beam and outputs light including optical sideband components, a phase modulator which phase-modulates another split carrier light beam, and second or third splitting means used to split the output light of the optical modulator into two light beams. The output light split by the second or third splitting means and the output light of the phase modulator are multiplexed to obtain the amplitude of the signal waveform of optical power, and the optical modulator is controlled such that the obtained value is minimized.
    Type: Grant
    Filed: September 28, 2012
    Date of Patent: December 3, 2019
    Assignee: SUMITOMO OSAKA CEMENT CO., LTD.
    Inventors: Takeshi Sakai, Masahito Mure, Junichiro Ichikawa
  • Patent number: 10483959
    Abstract: An example device includes splitter logic to split an input sample having a predetermined number of bits into a first segment of most significant bits and a second segment of least significant bits. Pulse logic generates a pattern of pulses that correlate to the values of the most significant bits. Edge mover logic determines edge adjustment data based on the values of the least significant bits, the edge adjustment data representing an adjustment to at least one edge in the pattern of pulses. Combiner logic generates an enhanced pulse stream by adjusting at least one edge in the pattern of pulses based on the edge adjustment data.
    Type: Grant
    Filed: August 7, 2018
    Date of Patent: November 19, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventor: Albrecht Lutz Naumann
  • Patent number: 10404376
    Abstract: A system for analyzing an optical transport network is provided. The system can generate a linear OSNR and an output power profile for each optical link element of an optical link based on an input power profile, amplifier characteristics, transport fiber characteristics, and a set of operating parameters. The system can generate a nonlinear OSNR for each optical link element based on the input power profile and transport fiber characteristics of each optical link element. The system can determine an expected performance metric for the optical link based on the linear OSNR, the non-linear OSNR, and a transmitter output OSNR. The system can designate the optical link as valid for use in the optical transport network if the expected performance metric is greater than or equal to a performance metric threshold.
    Type: Grant
    Filed: July 18, 2018
    Date of Patent: September 3, 2019
    Assignee: Google LLC
    Inventors: Rene Schmogrow, Vinayak Dangui
  • Patent number: 10404366
    Abstract: An optical signal monitor, including: a storage that holds a threshold value set for each of determination areas having a bandwidth set in accordance with an average grid of dummy light; a measurement section that sequentially measures an optical intensity of an inputted wavelength-multiplexed optical signal with respect to each of measurement areas obtained by dividing the determination area into areas with a bandwidth sufficiently smaller than a grid width of a monitoring-target optical signal composing the wavelength-multiplexed optical signal, and output measured values; and a section that determines that dummy light corresponding to the determination area needs introducing if each of measured values in the determination area is smaller than a threshold value, and, determines that dummy light corresponding to the determination area does not need introducing if at least one of the measured values in the determination area is equal to or larger than the threshold value.
    Type: Grant
    Filed: July 19, 2018
    Date of Patent: September 3, 2019
    Assignee: NEC CORPORATION
    Inventor: Yoshirou Satou
  • Patent number: 10361778
    Abstract: An optical signal monitor, including: a storage that holds a threshold value set for each of determination areas having a bandwidth set in accordance with an average grid of dummy light; a measurement section that sequentially measures an optical intensity of an inputted wavelength-multiplexed optical signal with respect to each of measurement areas obtained by dividing the determination area into areas with a bandwidth sufficiently smaller than a grid width of a monitoring-target optical signal composing the wavelength-multiplexed optical signal, and output measured values; and a section that determines that dummy light corresponding to the determination area needs introducing if each of measured values in the determination area is smaller than a threshold value, and, determines that dummy light corresponding to the determination area does not need introducing if at least one of the measured values in the determination area is equal to or larger than the threshold value.
    Type: Grant
    Filed: July 19, 2018
    Date of Patent: July 23, 2019
    Assignee: NEC CORPORATION
    Inventor: Yoshirou Satou
  • Patent number: 10341158
    Abstract: A segment-based approach for fast fourier transforms of input signals is provided for the generation of baseband signals. A FFT is performed individually for each of the segments from the input signal and the FFT result from each segment is accumulated to provide a final FFT for an input signal symbol. After the samples are received for one segment, a FFT can be performed to generate an intermediate FFT result while samples for the additional segment(s) are received. The system accumulates the intermediate result from the segments into a final FFT result that can be used to generate the baseband signal. Segment-based processing of an input signal can provide faster and more efficient processing to generate a baseband signal. Segment-based processing can also decrease the required size of the input buffers for antennas.
    Type: Grant
    Filed: May 17, 2017
    Date of Patent: July 2, 2019
    Assignee: Futurewei Technologies, Inc.
    Inventors: Weizhong Chen, Tao Zhang
  • Patent number: 10295406
    Abstract: An optical spectral analyzer for measuring an optical multi-channel signal by separating the multi-channel signal and measuring a plurality of single-channel signals simultaneously. The spectral analyzer can include a demultiplexer configured to receive the multi-channel signal. The multi-channel signal can be a multi-channel wavelength range. The demultiplexer can separate the multi-channel signal into the plurality of single-channel signals including a first single-channel signal and a second single-channel signal. The spectral analyzer can include a plurality of optical paths. The plurality of optical paths can include a plurality of respective detectors for measuring an optical power of the respective single-channel signals. The detectors can convert the optical power of the respective single-channel signals to corresponding electrical signals.
    Type: Grant
    Filed: June 30, 2017
    Date of Patent: May 21, 2019
    Assignee: Intel Corporation
    Inventors: Abram M Detofsky, Brett E Klehn
  • Patent number: 10284252
    Abstract: A transceiver (100) is disclosed for a communication node adapted to transmit a first signal to an other communication node and to receive a second signal from the other communication node. The transceiver comprises at least one antenna (110), at least one transmitter module (120), at least one receiver module (130), and a mode alternator (160). The at least one antenna is adapted to simultaneously transmit the first signal and receive the second signal, wherein the first and second signals have equal carrier frequencies and different polarizations. The second signal is for determining a channel characterization of a communication channel over which the second signal is received, and the channel characterization is for determination of one or more transmission parameters for the first signal. The mode alternator is adapted to alternate a mode of operation of the transceiver between at least a first and a second mode of operation.
    Type: Grant
    Filed: May 28, 2015
    Date of Patent: May 7, 2019
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Harald Jacobsson, Mats Rydström, Per-Arne Thorsén
  • Patent number: 10225016
    Abstract: Wavelength multiplexed optical communication systems include a channeled chromatic dispersion compensator coupled to receive modulated optical beams associated with a plurality of optical channels at respective communication wavelengths. The channeled chromatic dispersion compensator applies independently selected dispersion compensations to each of the optical channels by identifying a dispersion compensation associated with a preferred bit error rate, inter-symbol interference, or other signal quality metric, or determined using optical fiber properties such as dispersion slope and zero dispersion wavelength. Chromatic dispersion compensation can be coupled with channel power equalization, and can be performed at a receiver or a transmitter or in the middle of a fiber span.
    Type: Grant
    Filed: June 28, 2016
    Date of Patent: March 5, 2019
    Assignee: Amazon Technologies, Inc.
    Inventors: Salman Khaleghi, Emily Abbess, Christopher Rodenchuk, Alaa Adel Mahdi Hayder, Robert Harrison, Matt Connolly
  • Patent number: 10116432
    Abstract: A measuring instrument for measuring electrical characteristics of a device under test (DUT) includes a signal generator for generating a synchronization signal transmittable to a receiver and a phase shifter. The measuring instrument is configured to receive a retransmission of the synchronization signal from the receiver. The phase shifter configured to receive the synchronization signal from the signal generator and the retransmission of the synchronization signal from the receiver and shift a phase of the synchronization signal so that pulse edges of the synchronization signal are aligned at the measuring instrument and the receiver.
    Type: Grant
    Filed: December 29, 2017
    Date of Patent: October 30, 2018
    Assignee: ANRITSU COMPANY
    Inventor: Donald Anthony Bradley
  • Patent number: 10116408
    Abstract: The present disclosure describes a reconfigurable optical add-drop multiplexer including a wavelength selective switch configured to filter wavelengths of an optical signal; and an optical equalizer, coupled to the wavelength selective switch, configured to equalize the optical signal to mitigate optical filtering effects caused by the wavelength selective switch.
    Type: Grant
    Filed: August 10, 2016
    Date of Patent: October 30, 2018
    Assignee: AT&T Intellectual Propert I, L.P.
    Inventor: Xiang Zhou
  • Patent number: 10098027
    Abstract: In some embodiments, an apparatus includes a memory, a processor operatively coupled to the memory and a sensor. The sensor is configured to intercept a wireless signal associated with a vehicle. The processor configured to identify from the wireless signal (1) a bit rate of the wireless signal, (2) an encoding type associated with the wireless signal, and (3) data associated with the wireless signal. The processor configured to generate an identifier associated with the vehicle based on the bit rate, the encoding type and the data. The processor configured to correlate within the memory the identifier with additional data associated with a user of the vehicle.
    Type: Grant
    Filed: June 1, 2017
    Date of Patent: October 9, 2018
    Assignee: Anatrope, Inc.
    Inventors: Tiffany Strauchs Rad, Drew James Newman, Teague James Newman
  • Patent number: 10084547
    Abstract: This disclosure provides systems, methods, and apparatus for mitigating the effects of interference signals on optical signals received at a direct-detection optical receivers. The optical receivers are capable of attenuating interference noise signals resulting from the interference between a transmitted optical signal transmitted from a transmitter to the optical receiver and one or more additional signals received at the optical receiver. The interference can be due to multi-path interference or due to in-band interference. The receivers include a tunable filter for filtering the received optical signal to remove the interference. A frequency offset module processes the received optical signal to determine a frequency offset indicative of the difference between the carrier frequencies of a modulated optical signal and an interference optical signal.
    Type: Grant
    Filed: March 7, 2018
    Date of Patent: September 25, 2018
    Assignee: Google LLC
    Inventors: Xiang Zhou, Ryohei Urata, Erji Mao, Hong Liu, Christopher Lyle Johnson
  • Patent number: 10027412
    Abstract: Apparatuses, systems, and methods of communication using visible light communications (VLC) are provided. A system can include a VLC transmitter and a VLC receiver suitable for implementing a diversity combining technique. The diversity combining technique can include equal gain combining, selective best combining, and maximal ratio combining. The VLC transmitter can be a multi-element diversity transmitter and can provide illumination as well as data transfer.
    Type: Grant
    Filed: March 2, 2017
    Date of Patent: July 17, 2018
    Assignee: The Florida International University Board of Trustees
    Inventors: Yusuf S. Eroglu, Ismail Guvenc, Nezih Pala
  • Patent number: 10014938
    Abstract: Techniques are described for indicating a wavelength at which a network interface device is configured to operate. A first controller circuit may determine a wavelength at which the network interface device is operating. The wavelength at which the network interface device is operating includes at least one of an optical wavelength at which a laser of the network interface device is transmitting optical data or an optical wavelength at which a photodiode of the network interface device is receiving optical data. A second controller circuit may cause the network interface device to output a sensory output that indicates the wavelength at which the network interface device is operating.
    Type: Grant
    Filed: August 18, 2016
    Date of Patent: July 3, 2018
    Assignee: Calix, Inc.
    Inventor: Christopher T. Bernard
  • Patent number: 10014933
    Abstract: A method of transmitting communications traffic in an optical communication network comprising a plurality of nodes, the method comprising, at a source node: receiving communications traffic to be transmitted across the optical communication network to a target node; obtaining a path sequence defining an order in which a plurality of optical paths from the source node to the target node across the optical communication network are to be used, at least part of each optical path being spatially separate from each other optical path; and transmitting the communications traffic as a series of traffic portions, each traffic portion being transmitted for a respective preselected transmission period on a respective optical path according to the path sequence.
    Type: Grant
    Filed: October 15, 2013
    Date of Patent: July 3, 2018
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (publ)
    Inventors: Roberto Magri, Giulio Bottari
  • Patent number: 10009136
    Abstract: Methods, systems, and apparatus, for an external cavity FP laser. In one aspect, an apparatus is provided that includes a FP laser diode; a Faraday rotator (FR) coupled to receive an optical output of the FP laser diode and that rotates a polarization of the optical output; an optical fiber coupled at a first end to receive the output of the FR; a WDM filter coupled to a second end of the optical fiber to receive the optical signal from the optical fiber; and a FRM coupled directly or indirectly to an output of the WDM filter, wherein an optical output of the WDM filter is partially reflected by the FRM such that the polarization of a reflected beam is rotated, and wherein the reflected optical signal then passes through the FR with its polarization being rotated by the FR before it is injected back into the FP laser diode.
    Type: Grant
    Filed: May 1, 2017
    Date of Patent: June 26, 2018
    Assignee: Oplink Communications, LLC
    Inventors: Zuon-Min Chuang, Rang-Chen Yu, Domenico DiMola, Sung-Ping Huang
  • Patent number: 9960789
    Abstract: If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, it is difficult to make effective utilization of frequency resources without the power consumption increasing and the control becoming complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an interface means for converting a digital signal to be transmitted under a predetermined transmission condition over an optical carrier wave into a parallel signal with a predetermined bit number at a predetermined transmission rate, and outputting the parallel signal; an encoding means for encoding the parallel signal using one coding system from among a plurality of convolutional coding systems with different degrees of redundancy; a mapping means for mapping an output bit signal output from the encoding means to a modulation symbol; an optical modulation means for modulating the optical carrier wave based on a sy
    Type: Grant
    Filed: January 20, 2016
    Date of Patent: May 1, 2018
    Assignee: NEC CORPORATION
    Inventors: Tatsuya Nakamura, Emmanuel Le Taillandier De Gabory, Junichi Abe
  • Patent number: 9860053
    Abstract: Synchronizing SBS suppressing optical phase/frequency modulation of each of a plurality of optical transmitters can be achieved with a plurality of optical transmitters conveying a plurality of optical carriers; and a synchronizer coupled to each of the plurality of optical transmitters to synchronize the SBS suppressing optical phase/frequency modulation of each of the plurality of optical carriers.
    Type: Grant
    Filed: April 15, 2016
    Date of Patent: January 2, 2018
    Assignee: Aurora Networks, Inc.
    Inventors: Brian Ishaug, Sudhesh Mysore
  • Patent number: 9831944
    Abstract: A probe generator includes: a first demultiplexer configured to branch a first optical signal having a first wavelength into at least two first polarized optical signals; a first adjustor configured to adjust the first polarized optical signals such that the first polarized optical signals have the same polarization direction and to combine the adjusted first polarized optical signals into a second optical signal; a first modulator configured to branch the second optical signal into at least two first split optical signals and to intensity-modulate each of the first split optical signals with first pilot signals; a second adjustor configured to adjust the first split optical signals intensity-modulated by the first modulator such that the intensity-modulated first split optical signals have different polarization directions; and an output unit configured to combine the first split optical signals adjusted by the second adjustor to generate a probe optical signal to be output.
    Type: Grant
    Filed: March 18, 2016
    Date of Patent: November 28, 2017
    Assignee: FUJITSU LIMITED
    Inventor: Futoshi Izumi
  • Patent number: 9825731
    Abstract: An optical transmission system includes a first optical transmission apparatus that adds a plurality of error correction codes to a main signal, retrieves, from a first error correction code that is added to the main signal and that corresponds to a first sub-carrier among the plurality of sub-carriers, a first code portion in excess of a predetermined redundancy level, distributes the first code portion to a second sub-carrier among the plurality of sub-carriers, concatenates a second code portion into the first error correction code, and transmits an optical signal including the main signal multiplexed with the first error correction code that has been concatenated with the second code portion.
    Type: Grant
    Filed: March 1, 2016
    Date of Patent: November 21, 2017
    Assignee: FUJITSU LIMITED
    Inventors: Taizo Maeda, Yohei Koganei, Ichiro Nakajima
  • Patent number: 9768886
    Abstract: An optical receiver including: a phase modulation unit that generates local oscillation light and modulates a phase of the local oscillation light; a coherent detection unit that causes a received optical signal and the local oscillation light phase-modulated by the phase modulation unit to interfere and converts the optical signal to an electrical signal; a polarization separation/adaptive equalization unit that performs polarization separation and adaptive equalization on the electrical signal after coherent detection; and decoding units that decode the polarization-separated electrical signals outputted from the polarization separation/adaptive equalization unit.
    Type: Grant
    Filed: February 13, 2014
    Date of Patent: September 19, 2017
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Mitsuko Mieno, Tsuyoshi Yoshida, Hiroaki Shintaku, Shusaku Hayashi
  • Patent number: 9621276
    Abstract: An optical transmitter for transmitting a multilevel amplitude-shift-keying modulated signal includes an optical modulator for modulating an optical signal with a multilevel amplitude-shift-keying modulation, and a spectral filter adapted to increase a high-frequency component of the modulated optical signal relatively to a central frequency component. The multilevel ASK modulation is quaternary ASK and the symbol rate of the optical modulator is above 40 Gbaud. An optical link connects the optical transmitter to a quadratic direct detection optical receiver.
    Type: Grant
    Filed: June 21, 2013
    Date of Patent: April 11, 2017
    Assignee: Alcatel Lucent
    Inventors: Jeremie Renaudier, Gabriel Charlet, Haik Mardoyan
  • Patent number: 9602206
    Abstract: Disclosed are an apparatus and method configured to process video data signals operating on a passive optical network (PON). One example method of operation may include receiving a data signal at an optical distribution network node (ODN) and identifying signal interference in the data signal. The method may also include modifying a shape of the data signal in the electrical domain and transmitting the modified data signal to at least one optical termination unit (ONT).
    Type: Grant
    Filed: December 30, 2014
    Date of Patent: March 21, 2017
    Assignee: Alcatel Lucent
    Inventors: James J. Stiscia, Joe L. Smith
  • Patent number: 9450678
    Abstract: A system and method including a transmitter including digital signal processor for providing a shaped data output in response to an input data stream. The shaped data output is coupled to a modulator that modulates an optical signal in response to the shaped data output to provide a non-rectangular shaped output having channel spacing greater than Nyquist channel spacing. Providing a shaped output consistent the present disclosure mitigates the effects of non-linear impairments in an optical transmission system.
    Type: Grant
    Filed: October 1, 2014
    Date of Patent: September 20, 2016
    Assignee: Tyco Electronics Subsea Communications LLC
    Inventors: Matthew V. Mazurczyk, Oleg Sinkin, Dmitri Foursa, Alexei N. Pilipetskii
  • Patent number: 9407360
    Abstract: Disclosed is an optical line monitoring system and method which detects an optical line where a disorder occurs, by using an OTDR (Optical Time Domain Reflectometer) pulse pattern with matching information. The optical line monitoring system generates and stores a reference OTDR pulse pattern matched with identification information of an optical channel service unit, and compares the matched reference OTDR pulse pattern with the OTDR pulse pattern collected at an inspection time to verify an optical line region where a disorder occurs.
    Type: Grant
    Filed: October 10, 2012
    Date of Patent: August 2, 2016
    Assignee: LS CABLE LTD.
    Inventors: Ji-Sang Park, Lae-Hyuk Park, Ki-Yeul Kim, Kwan-Hee Han, Eun-Jeong Yang
  • Patent number: 9391712
    Abstract: An apparatus comprises a receiver configured to receive first messages, a processor coupled to the receiver and configured to process the first messages, determine transmission powers associated with the first messages, and generate a transmission scheme based on the transmission powers, and a transmitter coupled to the processor and configured to transmit a second message comprising the transmission scheme. An apparatus comprises a transmitter configured to transmit a first message indicating a transmission power of the apparatus, a receiver configured to receive a second message, wherein the second message assigns to the apparatus a wavelength based on the transmission power, and a processor coupled to the transmitter and the receiver and configured to process the second message, and instruct the transmitter to transmit a third message at the wavelength.
    Type: Grant
    Filed: June 16, 2014
    Date of Patent: July 12, 2016
    Assignee: Futurewei Technologies, Inc.
    Inventors: Yuanqiu Luo, Frank Effenberger
  • Patent number: 9331788
    Abstract: A communication device includes a signal correcting unit that performs signal correction on an electric signal indicating information to be transmitted to reduce signal deterioration occurring in transmission of the electric signal; a conversion unit that converts the electric signal subjected to the signal correction into a digital signal on which information indicating the signal correction performed by the signal correcting unit is superimposed; and a light-emitting element that emits light in accordance with the digital signal converted by the conversion unit.
    Type: Grant
    Filed: January 23, 2013
    Date of Patent: May 3, 2016
    Assignee: RICOH COMPANY, LIMITED
    Inventors: Hiroyuki Abe, Junichi Ikeda, Satoru Numakura, Mitsuru Suzuki
  • Patent number: 9332429
    Abstract: A spectral content of a baseband waveform is varied and a measure of the baseband waveform whose spectral content has been varied is used by a transmitter in order to convey information. According to embodiments of inventive concepts, a set of frequencies that is used to provide spectral content to the baseband waveform is varied. In some embodiments, the spectral content comprises non-contiguous first and second frequency intervals wherein a third frequency interval that is between the first and second frequency intervals remains substantially devoid of providing spectral content in order to reduce or avoid interference. In other embodiments, the spectral content that is varied comprises a bandwidth that is varied. The inventive concepts are relevant to 4G LTE carrier aggregation systems/methods and/or other aspects of 4G LTE. Various transmitter/receiver embodiments are disclosed including direct synthesis transmitter/receiver embodiments.
    Type: Grant
    Filed: August 11, 2014
    Date of Patent: May 3, 2016
    Assignee: Odyssey Wireless, Inc.
    Inventor: Peter D. Karabinis
  • Patent number: 9325206
    Abstract: A system for delivering optical power over optical conduits includes at least one optical power source delivering multiple optical power forms over an optical conduit with a counter propagating optical control signal.
    Type: Grant
    Filed: July 12, 2013
    Date of Patent: April 26, 2016
    Assignee: Deep Science, LLC
    Inventors: Alistair K. Chan, Roderick A. Hyde, Jordin T. Kare, Lowell L. Wood, Jr., Muriel Y. Ishikawa
  • Patent number: 9319137
    Abstract: Aspects of the present invention provide techniques for compensating nonlinear impairments of a signal traversing an optical communications system. A parallel array of linear convolutional filters are configured to process a selected set of samples of the signal to generate an estimate of a nonlinear interference field. The predetermined set of samples comprises a first sample and a plurality of second samples. A processor applies the estimated nonlinear interference field to the first sample to least partially compensate the nonlinear impairment.
    Type: Grant
    Filed: September 9, 2014
    Date of Patent: April 19, 2016
    Assignee: CIENA CORPORATION
    Inventors: Qunbi Zhuge, Shahab Oveis Gharan, Michael Andrew Reimer, Maurice O'Sullivan
  • Patent number: 9300400
    Abstract: An example apparatus comprises an optical transmitter which includes a first processor and at least two optical modulators. The first processor is configured to generate a first electronic representation for each of at least two optical signals for carrying payload data modulated according to a one-dimensional (1-D) modulation format, and to induce on respective ones of the first electronic representations an amount of dispersion that depends on a power-weighted accumulated dispersion (ADPW) of a transmission link through which the at least two optical signals are to be transmitted thereby generating complex-valued electronic representations of pre-dispersion-compensated optical signals. Each of the at least two optical modulators modulate a respective analog version corresponding to a respective one of the complex-valued electronic representations onto a polarization of an optical carrier.
    Type: Grant
    Filed: December 31, 2012
    Date of Patent: March 29, 2016
    Assignee: Alcatel Lucent
    Inventors: Xiang Liu, Peter J Winzer, Andrew R Chraplyvy, Robert W Tkach, Chandrasekhar Sethumadhavan
  • Patent number: 9258065
    Abstract: The present document relates to an optical communication system. In particular, the present document relates to the alignment of the laser frequency at a transmitter of the optical communication system and the local oscillator frequency at a coherent receiver of the optical communication system. A coherent optical receiver (222) is described. The receiver (222) comprises a reception unit adapted to convert a received optical signal at a carrier frequency into a digital signal using a local oscillator, referred to as LO, having an LO frequency; a spectral analysis unit adapted to estimate a degree of asymmetry of a spectrum of the received optical signal, based on the digital signal; and a transmission unit adapted to transmit an indication of the degree of asymmetry to a near-end transponder (210) comprising a transmitter (211) of the received optical signal.
    Type: Grant
    Filed: February 12, 2013
    Date of Patent: February 9, 2016
    Assignee: Alcatel Lucent
    Inventors: Massimiliano Salsi, Oriol Bertran-Pardo
  • Patent number: 9209900
    Abstract: An improved method and apparatus for reducing performance degradation in optical fiber transmission system due to polarization mode dispersion and nonlinear polarization coupling. Digital polarization scrambling with transmit and receive digital signal processing is used to reduce these effects. By performing digital polarization scrambling on all possible states of polarization with respect to the two principle axes of an optical fiber, the SOP dependent penalty is averaged out. The invention also provides a method and apparatus for performing digital polarization scrambling on the transmit side and blinded polarization tracking or synchronized polarization descrambling at the receive side. Using a configurable scrambling speed, the invention works as a polarization scanner low speed SOP rotation or as a scrambler at fast SOP rotation speeds.
    Type: Grant
    Filed: June 16, 2014
    Date of Patent: December 8, 2015
    Assignee: ZTE CORPORATION
    Inventor: Yi Cai
  • Patent number: 9190797
    Abstract: A method for generating an optical frequency comb with a defined number of frequency comb lines with an adjustable spacing therebetween includes generating an input frequency comb comprising a multiplicity of input frequency comb lines with a light source. Individual frequency comb lines having an identical frequency spacing are filtered out of the multiplicity of input frequency comb lines so as to obtain filtered frequency comb lines. A first modulating of the filtered frequency comb lines is performed at a first modulation frequency so as to generate first sideband lines. The first sideband lines are generated by the first modulating so that the filtered frequency comb lines and the first sideband lines have an identical frequency spacing.
    Type: Grant
    Filed: February 12, 2015
    Date of Patent: November 17, 2015
    Assignee: DEUTSCHE TELEKOM AG
    Inventor: Thomas Schneider
  • Patent number: 9188740
    Abstract: A waveguide pathway and a phased-array device utilizing the waveguide pathway are provided. The waveguide pathway comprises a two-dimensional array of homogeneous unit cells. Each unit cell includes a branch point leading to two waveguide branches. Each waveguide branch passes through a positive phase shift element and a negative phase shift element, in series, and with each waveguide branch passing through the two phase shift elements in opposite order relative to the other waveguide branch. Each unit cell additionally includes a convergence point where the two waveguide branches converge. The wavepath grid and the phased-array device are capable of producing output channels with linear, asymmetrical phase distribution but with symmetrical power distribution without employing amplifiers. The phased-array device can be tuned with single-channel or dual-channel control.
    Type: Grant
    Filed: May 22, 2014
    Date of Patent: November 17, 2015
    Assignee: Toyota Motor Engineering & Manufacturing North America, Inc.
    Inventor: Tsuyoshi Nomura
  • Patent number: 9104085
    Abstract: Method for modulating a carrier light wave with symbols, led through a modulating interferometer, the total path phase shift being the sum of a respective first, second, third or fourth static phase shift and a respective first, second, third or fourth variable modulating phase shift amount. For each of at least two symbols: the first variable modulating phase shift equals the sum of the first pair phase shift and the common phase shift; the second variable modulating phase shift equals the sum of the negative of the first pair phase shift and the common phase shift; the third variable modulating phase shift equals the sum of the second pair phase shift and the negative of the common phase shift; the fourth variable modulating phase shift equals the sum of the negative of the second pair phase shift and the negative of the common phase shift.
    Type: Grant
    Filed: September 4, 2013
    Date of Patent: August 11, 2015
    Assignee: FINISAR SWEDEN AB
    Inventor: Jan-Olof Wesstrom
  • Patent number: 9094117
    Abstract: A receiver applies a calibration method to compensate for skew between input channels. The receiver skew is estimated by observing the coefficients of an adaptive equalizer which adjusts the coefficients based on time-varying properties of the multi-channel input signal. The receiver skew is compensated by programming the phase of the sampling clocks for the different channels. Furthermore, during real-time operation of the receiver, channel diagnostics is performed to automatically estimate differential group delay and/or other channel characteristics based on the equalizer coefficients using a frequency averaging or polarization averaging approach. Framer information can furthermore be utilized to estimate differential group delay that is an integer multiple of the symbol rate. Additionally, a DSP reset may be performed when substantial signal degradation is detected based on the channel diagnostics information.
    Type: Grant
    Filed: January 17, 2013
    Date of Patent: July 28, 2015
    Assignee: ClariPhy Communications, Inc.
    Inventors: Shih Cheng Wang, Seyedmohammadreza Motaghiannezam, Matthew C. Bashaw
  • Patent number: 9036999
    Abstract: One aspect provides an optical communication system. The system includes an optical-to-digital converter, a frequency estimator and a symbol synchronizer. The optical-to-digital converter is configured to receive an optical OFDM bit stream including an OFDM symbol bearing payload data and a symbol header preceding the OFDM payload data. The frequency estimator is configured to determine a carrier frequency offset of the payload data from the symbol header. The symbol synchronizer is configured to determine a starting location of the payload data within the bit stream by cross-correlating a synchronization pattern within the symbol header with a model synchronization pattern stored by the symbol synchronizer.
    Type: Grant
    Filed: July 29, 2011
    Date of Patent: May 19, 2015
    Assignee: Alcatel Lucent
    Inventors: Noriaki Kaneda, Timo Pfau, Qi Yang
  • Patent number: 9036998
    Abstract: An undersea long-haul transmission system includes an optical fiber transmission span and a coherent detection and digital signal processing module for providing dispersion compensation. The transmission span includes at least one fiber pair comprising substantially equal lengths of a positive-dispersion first fiber and a negative-dispersion second fiber that are configured to provide a signal output at transmission distances greater than 10,000 km, in which the combined accumulated dispersion across the operating bandwidth does not exceed the dispersion-compensating capacity of the coherent detection and digital signal processing module. Further described is a fiber for use in an undersea long-haul transmission span. At a transmission wavelength of 1550 nm, the fiber has a dispersion coefficient in the range of ?16 to ?25 ps/nm·km, and a dispersion slope in the range of 0.04 to 0.02 ps/nm2·km.
    Type: Grant
    Filed: August 16, 2013
    Date of Patent: May 19, 2015
    Assignee: OFS FITEL, LLC
    Inventor: Ole A Levring
  • Patent number: 9031421
    Abstract: Provided is a method of measuring signal transmission time difference of a measuring device. The measuring device according to embodiments, by measuring a skew on two optical paths through signal delays of sufficient sizes for skew measurement on the optical paths, even a skew having a minute size can be measured within a measurable range.
    Type: Grant
    Filed: July 3, 2013
    Date of Patent: May 12, 2015
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Joong-Seon Choe, Chun Ju Youn, Jong-Hoi Kim, Duk Jun Kim, Yong-Hwan Kwon, Kwang-Seong Choi, Eun Soo Nam
  • Patent number: 9025962
    Abstract: A system for transmitting an optical signal between a host and a device according to a SATA protocol. The system comprises a transmitting-side converter for generating a logic one voltage value responsive to a data one value from an information source, for generating a logic zero voltage value responsive to a data zero value from the information source, for generating an idle state logic voltage value, wherein the idle state logic voltage value is (logic one voltage value+logic zero voltage value)/2, the transmitting-side converter comprising only linear functions to preserve the idle state logic voltage value, and an electrical-to-optical converter for converting the logic one, logic zero and the idle state logic voltage values to an optical signal further comprising respective logic one, logic zero and idle state optical values and for supplying the optical signal to an optical communications medium.
    Type: Grant
    Filed: January 28, 2013
    Date of Patent: May 5, 2015
    Inventor: James V Wernlund
  • Patent number: 9020338
    Abstract: A method for optically transmitting data between a transmitter and a receiver is disclosed, in which a color coding method based on a plurality of elemental colors is provided for the coding and transmission of the data, which color coding method involves a respective elemental color being sent by a respective transmitter-end optical radiation source and being received at the receiver end by a respective optical radiation receiver. The method provides for a control loop to be formed between the transmitter and the receiver, wherein the transmitter sends calibration messages to the receiver, and wherein a piece of compensation information is ascertained by comparing at least one channel property of at least one received calibration message with a corresponding channel property of at least one previously sent calibration message, and wherein the transmitter takes the compensation information as a basis for adjusting at least one transmission parameter.
    Type: Grant
    Filed: May 17, 2011
    Date of Patent: April 28, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventor: Joachim Walewski
  • Patent number: 9020365
    Abstract: Current optical networks are engineered to handle amplifier noise and chromatic dispersion. Polarization mode dispersion occurs in optical networks due splitting of the light energy of a pulse propagating in a fiber into two modes. Compensating for polarization mode dispersion is a difficult and expensive task and hence only few commercial systems have been deployed to deal with this issue. A polarization mode dispersion compensation module according to an example embodiment of the present invention compensates for polarization mode dispersion by determining a performance metric related to an error rate of an optical signal in at least one polarization mode in a filtered state. Based on the performance metric, a control vector is determined to control the optical signal in the at least one polarization mode in the filtered state. The control vector is then applied to a polarization effecting device to compensate for polarization mode dispersion.
    Type: Grant
    Filed: April 8, 2008
    Date of Patent: April 28, 2015
    Assignee: Tellabs Operations, Inc.
    Inventors: Richard C. Younce, Julia Y. Larikova
  • Patent number: 9008514
    Abstract: Example embodiments of the present invention relate to An optical node comprising of at least two optical degrees; a plurality of directionless add/drop ports; and at least one wavelength equalizing array, wherein the at least one wavelength equalizing array is used to both select wavelengths for each degree, and to perform directionless steering for the add/drop ports.
    Type: Grant
    Filed: June 22, 2013
    Date of Patent: April 14, 2015
    Inventors: Mark E. Boduch, Kimon Papakos