Feedback Patents (Class 398/209)
  • Patent number: 10285160
    Abstract: The present application discloses a method for transmitting, by a base station, a broadcast channel through a massive multiple-input multiple output (MIMO) antenna in a wireless communication system. Specifically, the method comprises the steps of: selecting broadcast channel dedicated antenna elements from among all antenna elements of the massive MIMO antenna; and transmitting the broadcast channel by performing a beamforming using the broadcast channel dedicated antenna elements. In the present invention, the power applied to the broadcast channel dedicated antenna elements in greater than the voltage applied to the remaining antenna elements.
    Type: Grant
    Filed: December 17, 2013
    Date of Patent: May 7, 2019
    Assignee: LG ELECTRONICS INC.
    Inventors: Soocheol Kyeong, Sungho Park, Kyunghaeng Lee, Hyunsoo Ko, Sunam Kim
  • Patent number: 10224879
    Abstract: A peak detector utilizes two choppers to cancel offset voltage of a transconductance amplifier, so the influence of the offset voltage is preventable and the peak detection accuracy of the peak detector can be improved significantly.
    Type: Grant
    Filed: December 26, 2017
    Date of Patent: March 5, 2019
    Assignee: NATIONAL SUN YAT-SEN UNIVERSITY
    Inventors: Chua-Chin Wang, Deng-Shian Wang, Hao-Chun Huang
  • Patent number: 9948396
    Abstract: The present invention is directed to data communication system and methods. More specifically, various embodiments of the present invention provide a communication interface that is configured to transfer data at high bandwidth using PAM format(s) over optical communication networks. A feedback mechanism is provided for adjusting the transmission power levels. There are other embodiments as well.
    Type: Grant
    Filed: September 29, 2016
    Date of Patent: April 17, 2018
    Assignee: INPHI CORPORATION
    Inventors: Sudeep Bhoja, Chao Xu, Hari Shankar
  • Patent number: 9915614
    Abstract: Methods, systems, and devices are disclosed for molecular capture, manipulation, and analysis. In one aspect, a device to aggregate and characterize particles in a fluid includes an electrically insulative substrate including a channel to carry an electrically conducting fluid containing particles, electrodes located in the channel forming a nanoscale opening and including an insulating layer over their surface at the opening, a first circuit to apply a non-uniform ac electric field and a dc bias signal across the electrodes, in which the applied non-uniform ac electric field produces a positive dielectrophoretic force to aggregate the particles in a trapping region including the opening and adjacent region, a second circuit to detect changes in a dc current caused by at least some of the particles in the trapping region, and an optical device that directs a coherent light beam on the opening to determine Raman spectra of the particles in the trapping region.
    Type: Grant
    Filed: April 26, 2013
    Date of Patent: March 13, 2018
    Assignees: ACADEMIA SINICA, MAX-PLANCK-INSTITUT FUR EISENFORSCHUNG GMBH
    Inventors: Chia-Fu Chou, Lesser-Rojas Leonardo, Ming-Lee Chu, Andreas Erbe
  • Patent number: 9843295
    Abstract: Disclosed is a transimpedance amplifier. The transimpedance amplifier includes an inverter configured to have a feedback resistor and amplify a signal provided to an input side, and a common gate amplifier configured to be connected to the inverter in cascade and amplify an output of the inverter, wherein the signal provided to the input side is fed forward to a gate of the common gate amplifier through a gate resistor.
    Type: Grant
    Filed: June 16, 2015
    Date of Patent: December 12, 2017
    Assignee: EWHA UNIVERSITY-INDUSTRY COLLABORATION FOUNDATION
    Inventors: Sung Min Park, Seung Hoon Kim
  • Patent number: 9774392
    Abstract: Systems and methods using a polarimetric measurement device to localize a source of one or more State of Polarization (SOP) transients affecting one or more optical fibers are disclosed. The method includes transmitting a signal into a fiber in a first direction; receiving, at the polarimetric measurement device, the signal from one of the fiber and another fiber collocated in a bundle with the fiber in a second direction; and processing data from the polarimetric measurement device to determine a location of the one or more SOP transients. The processing can include detecting a presence of the one or more SOP transients based on a first signature and its echo seen in the data; and converting a time between the echoes into a distance.
    Type: Grant
    Filed: September 25, 2015
    Date of Patent: September 26, 2017
    Assignee: Ciena Corporation
    Inventors: David R. Doucet, Douglas Charlton, David C. Bownass, Maurice S. O'Sullivan, Joanne Wakefield
  • Patent number: 9602202
    Abstract: Methods and systems for replicating current outputs from a photodetector include using a transimpedance (TIA) amplifier to directly generate a TIA output voltage that is linear with optical power at the photodetector. Additionally, a first logarithmic amplifier is used to generate a first output voltage from the photodetector current and a second logarithmic amplifier is used to generate a second voltage from a copy of the photodetector current. The first voltage and the second voltage may be linear in some cases with the optical power in decibels.
    Type: Grant
    Filed: September 9, 2015
    Date of Patent: March 21, 2017
    Assignee: Fujitsu Limited
    Inventors: Christopher Mesibov, Noah Gottfried, Idan Mandelbaum
  • Patent number: 9479264
    Abstract: An apparatus comprising a receiver optical subassembly (ROSA) configured to receive an optical signal, wherein the ROSA comprises an optical-electrical (O/E) converter configured to convert the optical signal into an electrical signal, and a processor coupled to the ROSA and configured to calibrate an O/E converter bias, wherein calibrating the O/E converter bias comprises reading an initial O/E converter dark current measurement, adjusting the O/E converter bias with a voltage step, reading an adjusted O/E converter dark current measurement after the voltage step adjustment, and monitoring an O/E converter dark current change rate by subtracting the initial O/E converter dark current measurement from the adjusted O/E converter dark current measurement.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: October 25, 2016
    Assignee: Futurewei Technologies, Inc.
    Inventors: Ning Cheng, Guo Wei, Zhenxing Liao
  • Patent number: 9467231
    Abstract: The present invention is directed to data communication system and methods. More specifically, various embodiments of the present invention provide a communication interface that is configured to transfer data at high bandwidth using PAM format(s) over optical communication networks. A feedback mechanism is provided for adjusting the transmission power levels. There are other embodiments as well.
    Type: Grant
    Filed: January 19, 2015
    Date of Patent: October 11, 2016
    Assignee: INPHI CORPORATION
    Inventors: Sudeep Bhoja, Chao Xu, Hari Shankar
  • Patent number: 9270386
    Abstract: Techniques are disclosed for detecting image depth in three-dimensional (3-D) surface imaging. The disclosed techniques can be used, for example, to provide structured light encoded with a coded word that includes error-correcting code (ECC). The ECC is effectively configured to detect and correct data errors as may result, for example, from the presence of ambient light and/or camera-noise-causing errors during imaging. In an example case, the coded word is a 15-bit pattern provided in a 3×5 matrix and including: (1) nine data bits of disparity code; (2) five ECC bits for correcting an error and detecting two errors; and (3) one 8-bit/10-bit encoding bit to ensure the presence of a transient pixel in the data for white threshold level detection. Greater or lesser bit quantities and varied bit partitioning matrices can be provided, as desired. In some cases, imaging robustness and/or power usage can be improved using the disclosed techniques.
    Type: Grant
    Filed: June 24, 2013
    Date of Patent: February 23, 2016
    Assignee: INTEL CORPORATION
    Inventor: David D. Bar-On
  • Patent number: 9237002
    Abstract: One embodiment includes a circuit system. The system includes a power detector configured to convert an AC signal to a DC signal corresponding to a power amplitude associated with the AC signal. The AC signal can include a periodic signal power null. The system also includes a null-gating circuit comprising a logic switch that is activated to enable sampling of an amplitude of the DC signal and that is deactivated during the periodic signal power null. The system also includes an analog-to-digital converter (ADC) configured to convert the sampled DC signal to a digital signal. The system further includes a processor configured to process the digital signal.
    Type: Grant
    Filed: January 30, 2014
    Date of Patent: January 12, 2016
    Assignee: Imagine Communications Corp.
    Inventor: William Ty Chizevsky
  • Patent number: 9236851
    Abstract: A direct conversion radio-frequency (RF) receiver includes a controller and an adaptive continuous-time filter. The adaptive continuous-time filter receives a multiple-bit control signal generated by the controller to adjust a characteristic of the continuous-time filter. The controller generates the multiple-bit control signal in response to process variation in the semi-conductor material used to implement the controller and the adaptive continuous-time filter. A method for tuning an adaptive continuous-time filter comprises determining a RC time constant, converting the RC time constant to a digital word, comparing a select bit of the digital word to a respective bit of a predetermined reference word to generate a control bit, applying the control bit to an adjustable element to modify the RC time constant, repeating the determining, converting, comparing and applying steps until the control bits generate an output word and providing the output word to the adaptive continuous-time filter.
    Type: Grant
    Filed: February 6, 2012
    Date of Patent: January 12, 2016
    Assignee: Skyworks Solutions, Inc.
    Inventors: Edward Youssoufian, Aly M. Ismail, Geoffrey Hatcher
  • Patent number: 9197324
    Abstract: The present invention is directed to data communication system and methods. More specifically, various embodiments of the present invention provide a communication interface that is configured to transfer data at high bandwidth using PAM format(s) over optical communication networks. A feedback mechanism is provided for adjusting the transmission power levels. There are other embodiments as well.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: November 24, 2015
    Assignee: Inphi Corporation
    Inventors: Sudeep Bhoja, Chao Xu, Hari Shankar
  • Patent number: 9116810
    Abstract: Described are methods and circuits for margin testing digital receivers. These methods and circuits prevent margins from collapsing in response to erroneously received data, and can thus be used in receivers that employ historical data to reduce intersymbol interference (ISI). Some embodiments detect receive errors for input data streams of unknown patterns, and can thus be used for in-system margin testing. Such systems can be adapted to dynamically alter system parameters during device operation to maintain adequate margins despite fluctuations in the system noise environment due to e.g. temperature and supply-voltage changes. Also described are methods of plotting and interpreting filtered and unfiltered error data generated by the disclosed methods and circuits. Some embodiments filter error data to facilitate pattern-specific margin testing.
    Type: Grant
    Filed: July 17, 2014
    Date of Patent: August 25, 2015
    Assignee: Rambus Inc.
    Inventors: Andrew Ho, Vladimir Stojanovic, Bruno W. Garlepp, Fred F. Chen
  • Patent number: 9071478
    Abstract: A method for performing adaptive equalization includes: dynamically detecting current levels of a plurality of sets of pattern levels respectively corresponding to a plurality of data patterns, wherein each set of the sets of pattern levels includes a previous level, a current level, and a next level respectively corresponding to one of the plurality of data patterns; and dynamically calculating a plurality of data decision levels according to the current levels of the sets of pattern levels, for use of data decision, wherein each data decision level of at least one portion of the plurality of data decision levels is not equal to zero, and the data decision levels are dynamically adjusted in accordance with the current levels of the sets of pattern levels, in order to enhance a signal-to-noise ratio (SNR). An associated method for performing adaptive equalization is also provided. Associated apparatus are also provided.
    Type: Grant
    Filed: May 24, 2011
    Date of Patent: June 30, 2015
    Assignee: MEDIATEK INC.
    Inventors: Yan-Bin Luo, Kuan-Hua Chao
  • Patent number: 9042820
    Abstract: An optical receiver circuit is disclosed in which a number of electrical signals are processed to extract data encoded therein. The electrical signals may be compared during the process to selectively remove one or more waveforms from one or more corresponding electrical signals. Various data signals, each including one or more waveforms, may then be processed to extract the encoded data. The optical receiver circuit reduces, or eliminates, electrical offsets which may be present in one or more of the electrical signals to reduce corresponding errors in the encoded data signals.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: May 26, 2015
    Assignee: Infinera Corporation
    Inventors: Huan-Shang Tsai, Jeffrey T. Rahn
  • Patent number: 9042741
    Abstract: Described herein are systems and methods for accurately estimating and removing a carrier frequency offset. One exemplary embodiment relates to a system comprising a frequency offset detection circuit detecting a carrier frequency offset in an optical signal, and a frequency testing circuit calculating an estimated frequency offset value of the carrier frequency offset, wherein the frequency testing circuit removes a carrier phase based on the estimated frequency offset value and recovers the optical signal. Another exemplary embodiment relates to a method comprising detecting a carrier frequency offset in an optical signal, calculating an estimated frequency offset value of the carrier frequency offset, removing a carrier phase based on the estimated frequency offset value, and recovering the optical signal.
    Type: Grant
    Filed: March 15, 2011
    Date of Patent: May 26, 2015
    Assignee: AT&T INTELLECTUAL PROPERTY I, L.P.
    Inventor: Xiang Zhou
  • Patent number: 9031420
    Abstract: An optical signal is converted into an electric signal by an O/E converter on the reception side, and converted into a digital signal by an analog/digital conversion unit. In a capture unit A at the input stage of the digital signal processing unit at the next stage, the constellation of a signal output from an analog/digital conversion unit is acquired for each polarization. According to the constellation information, the amplitude value of the electric signal input to the analog/digital conversion unit is corrected so that the value is optimum. Also, the capture unit B acquires the constellation on the signal after the demodulation by the digital signal processing. According to the constellation information, the amplitude of the I and Q signals and the skew between the I and Q signals are corrected.
    Type: Grant
    Filed: February 5, 2013
    Date of Patent: May 12, 2015
    Assignee: Fujitsu Limited
    Inventor: Yuichirou Sakamoto
  • 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: 9031415
    Abstract: An Ethernet adapter system may include a transmitter to insert a payload type identifier sequence in a generic frame procedure header to indicate that a network is a converged enhanced Ethernet network. The transmitter may insert idle sequences in a stream of data frames transmitted along a link. The system may include a receiver to recognize a condition and to force a loss of synchronization condition on the link that will be converted by the receiver into a loss of light condition. The receiver may scan the transmitted stream of data frames for invalid data frames and introduce a code into the stream of data frames whenever an invalid data frame is detected.
    Type: Grant
    Filed: December 8, 2012
    Date of Patent: May 12, 2015
    Assignee: International Business Machines Corporation
    Inventors: Casimer M. DeCusatis, Thomas A. Gregg, Rajaram B. Krishnamurthy
  • Patent number: 9025971
    Abstract: An optical receiving circuit includes: a first non-feedback amplifier configured to convert a current signal, obtained from a light receiving element in response to an optical signal, into a first voltage signal; a second amplifier configured to convert an input current signal into a second voltage signal, the output signal not being directly fed back to an input side; a differential amplifier configured to perform differential amplification on the first voltage signal and the second voltage signal and to output an in positive signal and a negative signal obtained through the differential amplification; and an offset compensation circuit configured to input, on the basis of the in positive signal and the negative signal output from the differential amplifier, an offset current signal in accordance with an offset of a level of the in positive signal from a level of the negative signal to the second amplifier.
    Type: Grant
    Filed: November 27, 2013
    Date of Patent: May 5, 2015
    Assignee: Fujitsu Limited
    Inventor: Satoshi Ide
  • Patent number: 9025969
    Abstract: An optical signal receiver tracks local oscillator frequency offset (LOFO) and compensates for the phase distortion introduced in the received signals as a result of utilizing the local oscillator within a coherent detection scheme. This phase distortion is basically a constant phase rotation caused by the LOFO and implementation of the receiver using coherent detection and a digital interferometer instead of a conventional (yet complex) carrier phase estimation or recovery scheme. With an optical receiver implemented in this manner, the requirement of using a precise local oscillator laser with low frequency offset is less important.
    Type: Grant
    Filed: May 24, 2012
    Date of Patent: May 5, 2015
    Assignee: Futurewei Technologies, Inc.
    Inventors: Chuandong Li, Yuanjie Chen, Zhuhong Zhang, Yi Cai, Fei Zhu
  • Patent number: 9020366
    Abstract: Provided are a polarization multiplexing optical receiving device and a polarization multiplexing optical receiving method with which a mismatch of optical intensity between polarized signals accumulated in an optical transmission path of an optical receiving system can be compensated with high precision, and a high-quality polarized optical signal can be received.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: April 28, 2015
    Assignee: NEC Corporation
    Inventor: Takeshi Okamoto
  • Patent number: 9014575
    Abstract: In a sampling clock synchronizing apparatus, an A/D converter converts an analog signal to a digital signal based on a sampling clock, and a processor compensates a band limitation due to spectral narrowing by filter characteristics of characteristics opposite to those of the spectral narrowing with respect to a signal produced from the A/D converter subjected to the spectral narrowing, and detects a phase shift in the sampling clock based on a signal after the compensation of the spectral narrowing and synchronizes sampling timing.
    Type: Grant
    Filed: January 6, 2012
    Date of Patent: April 21, 2015
    Assignee: Fujitsu Limited
    Inventors: Hisao Nakashima, Takeshi Hoshida
  • Patent number: 9014574
    Abstract: In order to appropriately demultiplex the polarization multiplexed BPSK signal without using a training sequence and decreasing the resistance to a frequency offset, an optical receiver includes a coherent optical detection unit receiving an optical signal in which BPSK modulated carrier waves are polarization-multiplexed, performing coherent detection by mixing the received optical signal with local light, and outputting first electrical signals corresponding to the carrier waves; a butterfly FIR filter receiving the first electrical signals and extracting second electrical signals corresponding to each of the carrier waves from the first electrical signals; and a coefficient control unit for calculating a sum of respective phases of the second electrical signals output from the butterfly FIR filter, adaptively controlling tap coefficients of the butterfly FIR filter so that the calculated phase sum may become equal to 0 or ?, and outputting tap coefficients after being controlled to the butterfly FIR filter
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: April 21, 2015
    Assignee: NEC Corporation
    Inventors: Manabu Arikawa, Daisaku Ogasahara, Emmanuel Le Taillandier de Gabory, Kiyoshi Fukuchi
  • Patent number: 9002215
    Abstract: A coherent optical receiver measures a portion of a spectra of a multi-channel optical signal that includes at least one signal adjacent to a selected signal. The coherent optical receiver determines structure and bandwidth information for the measured portion of spectra, and determines one or more filter parameters for the selected signal based on the structure and bandwidth information of the at least one signal adjacent to the selected signal. The coherent optical receiver adjusts one or more active filter parameters of a carrier phase estimator in the optical coherent receiver to have values corresponding to the determined one or more filter parameters.
    Type: Grant
    Filed: July 11, 2013
    Date of Patent: April 7, 2015
    Assignee: Oclaro, Inc.
    Inventor: Sunil Kumar Singh Khatana
  • Patent number: 8989602
    Abstract: A digital coherent optical receiver includes a processor that is operative to separate electric signals obtained by converting an optical signal into a horizontal signal component and a vertical signal component; to generate a histogram of the horizontal signal component and the vertical signal component as outputs of the equalizing filter; and to determine a presence/absence of local convergence based on distribution of the histogram of the horizontal signal component and the histogram of the vertical signal component.
    Type: Grant
    Filed: October 27, 2011
    Date of Patent: March 24, 2015
    Assignee: Fujitsu Limited
    Inventors: Kosuke Komaki, Osamu Takeuchi
  • Patent number: 8977138
    Abstract: A technique is provided for configuring an optical receiver. A photo detector is connected to a load resistor, and the photo detector includes an internal capacitance. A current source is connected through a switching circuit to the load resistor and to the photo detector. The current source is configured to discharge the internal capacitance of the photo detector. The switching circuit is configured to connect the current source to the internal capacitance based on a previous data bit.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: March 10, 2015
    Assignee: International Business Machines Corporation
    Inventors: Jonathan E. Proesel, Alexander V. Rylyakov, Clint L. Schow, Yurii A. Vlasov
  • Patent number: 8977141
    Abstract: A parameter of an adaptive filter is optimized so that inter-symbol interference having an amount corresponding to an inserted fixed filter remains.
    Type: Grant
    Filed: February 7, 2012
    Date of Patent: March 10, 2015
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Kengo Horikoshi, Etsushi Yamazaki, Takayuki Kobayashi, Eiji Yoshida, Yutaka Miyamoto
  • Patent number: 8965218
    Abstract: According to one embodiment, a photo detector-combined illuminance sensor includes a circuit for a Photo Detector (PD) function to detect the illuminance of the ambient environment. The illuminance sensor operates under the control of a controller in a visible light communication terminal. When an optical signal detected by the illuminance sensor is a visible light communication signal, the controller switches to cause the illuminance sensor to operate as the photo detector for the visible light communication in a visible light communication mode.
    Type: Grant
    Filed: July 12, 2012
    Date of Patent: February 24, 2015
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-Seung Son, Tae-Han Bae, Eun-Tae Won
  • Patent number: 8958706
    Abstract: A coherent optical communication device includes a demodulator configured to demodulate a reception signal; a local oscillator light optical source configured to generate local oscillator light used for demodulating the reception signal; a memory configured to store wavelength information; and a controller configured to control the local oscillator light optical source when the demodulator cannot receive the reception signal, so that a wavelength of the local oscillator light generated in the local oscillator light optical source is changed to a wavelength specified by the wavelength information stored in the memory.
    Type: Grant
    Filed: January 25, 2011
    Date of Patent: February 17, 2015
    Assignee: Fujitsu Limited
    Inventor: Takuji Maeda
  • Patent number: 8953952
    Abstract: An optical receiver, a method of operating an optical receiver, a correction based transimpedance amplifier circuit, and a method of adjusting an output of a transimpedance amplifier. In one embodiment, the optical receiver comprises an optical-to-electrical converter, a transimpedance amplifier, and a correction circuit. The optical-to-electrical converter is provided for receiving an optical signal and converting the optical signal to an electrical signal. The transimpedance amplifier is provided for receiving the electrical signal from the converter and for generating from the electrical signal an amplified electrical signal. The amplified electrical signal has inter symbol interference resulting from a reduced bandwidth of the transimpedance amplifier.
    Type: Grant
    Filed: August 28, 2012
    Date of Patent: February 10, 2015
    Assignee: International Business Machines Corporation
    Inventors: Jonathan E. Poesel, Alexander V. Rylyakov, Clint L. Schow, Yurii A. Vlasov
  • Patent number: 8948613
    Abstract: In part, aspects of the invention relate to methods, apparatus, and systems for intensity and/or pattern line noise reduction in a data collection system such as an optical coherence tomography system that uses an electromagnetic radiation source and interferometric principles. In one embodiment, the noise is intensity noise or line pattern noise and the source is a laser such as a swept laser. One or more attenuators responsive to one or more control signals can be used in conjunction with an analog or digital feedback network in one embodiment.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: February 3, 2015
    Assignee: Lightlab Imaging, Inc.
    Inventors: Joseph M. Schmitt, Victor Grinberg
  • Patent number: 8934783
    Abstract: An Ethernet adapter system may include a transmitter to insert a payload type identifier sequence in a generic frame procedure header to indicate that a network is a converged enhanced Ethernet network. The transmitter may insert idle sequences in a stream of data frames transmitted along a link. The system may include a receiver to recognize a condition and to force a loss of synchronization condition on the link that will be converted by the receiver into a loss of light condition. The receiver may scan the transmitted stream of data frames for invalid data frames and introduce a code into the stream of data frames whenever an invalid data frame is detected.
    Type: Grant
    Filed: February 17, 2011
    Date of Patent: January 13, 2015
    Assignee: International Business Machines Corporation
    Inventors: Casimer M. DeCusatis, Thomas A. Gregg, Rajaram B. Krishnamurthy
  • Patent number: 8929743
    Abstract: A scheme is described of remote control of the slicing level of a receiver in a smart SFP (or SFP+, or XFP) duplex (or BiDi, or SWBiDi) transceiver in a communication system using an operating system with OAM and PP functions, an OAM, PP & Payload Processor, a transceiver, a BERT, and an optical link in the field.
    Type: Grant
    Filed: August 11, 2011
    Date of Patent: January 6, 2015
    Assignee: Optoelectronics Solutions Co., Ltd.
    Inventors: Kwang Soo Park, Moon Soo Park
  • Patent number: 8923708
    Abstract: A signal processing device includes: a phase controller configured to control respective phases of an in-phase signal and an quadrature signal, which are obtained by converting an analog signal into a digital signal when a multi-value phase modulation light is demodulated, by digital signal processing; and a control amount provider configured to provide a control amount to the phase controller based on an output of the phase controller.
    Type: Grant
    Filed: February 17, 2010
    Date of Patent: December 30, 2014
    Assignee: Fujitsu Limited
    Inventor: Takahito Tanimura
  • Patent number: 8923694
    Abstract: An optical receiving device includes: an optical amplifier configured to amplify a wavelength multiplexed optical signal; a demultiplexer configured to demultiplex the amplified wavelength multiplexed signal into optical signals of a plurality of wavelengths; optical receivers configured to regenerate the demultiplexed optical signals; error correction units configured to correct a bit error in the regenerated optical signals; and main control unit. The control unit adjusts RXDTV of the optical receiver for receiving optical signals of a given wavelength to the optimal value in the state where the gain of the optical amplifier is lowered from that of a normal operation such that the occurrence of bit errors in the optical signals of the other wavelengths does not exceed the correction capability of the error correction unit.
    Type: Grant
    Filed: February 4, 2013
    Date of Patent: December 30, 2014
    Assignees: Fujitsu Telecom Networks Limited, Fujitsu Limited
    Inventors: Toshiki Honda, Takehiro Fujita, Yasushi Sugaya
  • Patent number: 8903255
    Abstract: A polarization-multiplexed signal receiver includes a polarization adjustment unit to adjust a polarization state of inputted polarization-multiplexed signal, which is carrying signal data on each of two polarized waves being inputted, based on a control signal and to output the adjusted polarization-multiplexed signal, an optical signal reception unit to convert the polarization-multiplexed signal having the adjusted polarization state into an analog electric signal and output the analog electric signal, an A/D conversion unit to convert the analog electric signal into a digital electric signal and output the digital electric signal, a digital signal processing unit to perform digital coherent processing to the digital electric signal and take out the signal data and a feedback control unit to generate the control signal based on quality of the signal data and output the signal data to the polarization adjustment unit.
    Type: Grant
    Filed: August 1, 2012
    Date of Patent: December 2, 2014
    Assignee: NEC Corporation
    Inventor: Takeshi Okamoto
  • Patent number: 8897396
    Abstract: Provided is a pulse receiver capable of receiving a burst signal and decoding the burst signal with a bit error rate reduced to a target value or less by controlling a determination threshold such that decoding success rate is equal to or less than a predetermined value. A decode unit 140 decodes a pulse train 20 to information 30, counts the number of decoding successes for a predetermined time period and outputs the counted number (decoding success rate DR) to a control unit 150. The control unit 150 uses as a basis the decoding success rate DR communicated from the decode unit 140 to control the set value of reference voltage Vth used in the comparator 130.
    Type: Grant
    Filed: August 15, 2012
    Date of Patent: November 25, 2014
    Assignees: Furukawa Electric Co., Ltd., Furukawa Automotive Systems Inc.
    Inventors: Hiroyuki Itohara, Kazutaka Kamimura, Yasushi Aoyagi
  • Patent number: 8897655
    Abstract: An optical transport system in which (i) an optical transmitter is configured to adaptively change an operative constellation to use a constellation that provides optimal performance characteristics for the present optical-link conditions and/or (ii) an optical receiver is configured to change shapes of the decision regions corresponding to an operative constellation to adapt them to the type of signal distortions experienced by a transmitted optical signal in the optical link between the transmitter and receiver. Under some optical-link conditions, the optical receiver might use a decision-region configuration in which a decision region corresponding to a first constellation point includes an area that is closer in distance to a different second constellation point than to the first constellation point.
    Type: Grant
    Filed: June 18, 2012
    Date of Patent: November 25, 2014
    Assignee: Alcatel Lucent
    Inventors: René-Jean Essiambre, Chongjin Xie
  • Patent number: 8897656
    Abstract: A system may include one or more devices that may be used to simultaneously measure and modulate phases of a many-channel optical system relative to a high frequency optical carrier. This device may be constructed using analog-to-digital converters, comparators, and distributed timers. A digital processor may be used to recover phase information from the measurements and to calculate an error compared to desired phase. The processor may then apply feedback to a phase modulator to correct the phase.
    Type: Grant
    Filed: July 7, 2011
    Date of Patent: November 25, 2014
    Assignee: EM Photonics, Inc.
    Inventors: Petersen F. Curt, Michael R. Bodnar
  • Patent number: 8891979
    Abstract: A photon detection system including a photon detector configured to detect single photons, a signal divider to divide the output signal of the photon detector into a first part and a second part, wherein the first part is substantially identical to the second part, a delay mechanism to delay the second part with respect to the first part, and a combiner to combine the first and delayed second parts of the signal such that the delayed second part is used to cancel periodic variations in the first part of the output signal.
    Type: Grant
    Filed: February 29, 2008
    Date of Patent: November 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Zhiliang Yuan, Andrew James Shields
  • Patent number: 8891978
    Abstract: At least one cell implementing a sensor array embraces a photoelectric-conversion accumulation element configured to generate and accumulate signal charges, a potential detection circuit configured to detect the signal charges generated by the photoelectric-conversion accumulation element as a potential change, and an amplification circuit configured to amplify the potential change and to transmit to an output-signal line. The photoelectric-conversion accumulation element and the potential detection circuit are connected in series between a first potential terminal and a second potential terminal, and the potential detection circuit has an insulated-gate transistor, which detects the potential change in a weak inversion state, in a period when an optical-communication signal is received.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: November 18, 2014
    Assignee: National University Corporation Shizuoka University
    Inventors: Shoji Kawahito, Isamu Takai, Michinori Ando
  • Patent number: 8891980
    Abstract: Methods, systems, and devices are described for a digital demodulator device for processing received optical signals. The device may include a quadrature error filter that receives a digitized version of an optical signal, and removes quadrature errors to generate a filtered series of data samples. The device may also include a frequency offset removal module for performing frequency rotation on the filtered series of data samples. The device may include a chromatic dispersion compensation module which removes chromatic dispersion from horizontal and vertical polarization channels. The device may include a polarization mode dispersion (PMD)/polarization dependent loss (PDL) compensation module which compensates for interference caused by PMD and PDL. The device may also include a phase recovery module configured to track and correct phase.
    Type: Grant
    Filed: February 10, 2014
    Date of Patent: November 18, 2014
    Assignee: ViaSat, Inc.
    Inventors: Fan Mo, William Thesling, Matthew Nimon, Sameep Dave
  • Patent number: 8886051
    Abstract: Compensation for in-phase (I) and quadrature (Q) timing skew and offset in an optical signal may be achieved based on the correlation between derivatives of I and Q samples in the optical signal. The magnitude of the correlation between derivatives is measured to determine the presence of skew. Correlation between derivatives may be coupled with frequency offset information and/or with trials having additional positive and negative skew to determine presence of skew. Correlations are determined according to pre-defined time periods to provide for continued tracking and compensation for timing skew that may result from, for example, thermal drift.
    Type: Grant
    Filed: February 12, 2014
    Date of Patent: November 11, 2014
    Assignee: ViaSat, Inc.
    Inventors: Yuri Zelensky, Fan Mo
  • Patent number: 8879927
    Abstract: An optical receiver, a method of operating an optical receiver, a correction based transimpedance amplifier circuit, and a method of adjusting an output of a transimpedance amplifier. In one embodiment, the optical receiver comprises an optical-to-electrical converter, a transimpedance amplifier, and a correction circuit. The optical-to-electrical converter is provided for receiving an optical signal and converting the optical signal to an electrical signal. The transimpedance amplifier is provided for receiving the electrical signal from the optical-to-electrical converter and for generating from the electrical signal an amplified electrical signal. The amplified electrical signal has inter symbol interference resulting from a reduced bandwidth of the transimpedance amplifier.
    Type: Grant
    Filed: March 2, 2011
    Date of Patent: November 4, 2014
    Assignee: International Business Machines Corporation
    Inventors: Jonathan E. Proesel, Alexander V. Rylyakov, Clint L. Schow, Yurii A. Vlasov
  • Patent number: 8873974
    Abstract: An embodiment of the invention is a technique to equalize received samples. A coefficient generator generates filter coefficients using an error vector and input samples. A filter stage generates equalized samples from input samples using the filter coefficients. The received samples are provided by a receiver front end in an optical transmission channel carrying transmitted symbols. Other embodiments are also described.
    Type: Grant
    Filed: May 7, 2013
    Date of Patent: October 28, 2014
    Assignee: Fundación Tarpuy
    Inventors: Mario Rafael Hueda, Diego Ernesto Crivelli, Hugo Santiago Carrer
  • Publication number: 20140301743
    Abstract: A light receiving device includes: a converter digitalizing an analog signal with a given sampling clock frequency, the analog signal being obtained through a photoelectric conversion of a received optical signal; a plurality of fixed distortion compensators compensating an output signal of the converter for waveform distortion with a fixed compensation amount that is different from each other; a plurality of phase shift detector circuits detecting a sampling phase shift from an output signal of the plurality of the fixed distortion compensators; a phase-adjusting-amount determiner determining a sampling phase adjusting amount with use of an output signal of the plurality of the phase shift detector circuits; and a phase adjusting circuit reducing a phase difference between the sampling clock frequency and the received optical signal based on a determination result of the phase-adjusting-amount determiner.
    Type: Application
    Filed: November 25, 2013
    Publication date: October 9, 2014
    Applicant: FUJITSU LIMITED
    Inventors: Hisao NAKASHIMA, Takeshi HOSHIDA
  • Patent number: 8855504
    Abstract: An optical receiver has an adaptive optical compensator and/or an adaptive electrical equalizer for compensating signal distortion in a received optical signal. In order to achieve a very fast adaptation of the receiver to the actual signal distortion, which is important for example for bursts mode optical signals in a packet-switched optical transmission network, at least one predetermined trainings sequence is provided in the optical signal, which is known at the receiver and thus enables fast adaptation of the compensator and/or equalizer to the actual signal distortion.
    Type: Grant
    Filed: June 23, 2004
    Date of Patent: October 7, 2014
    Assignee: Alcatel Lucent
    Inventor: Henning Bülow
  • Patent number: 8848747
    Abstract: A method for recovering an OTUk frame includes: receiving an optical signal sent by using a method of multi-lane distribution from the OTUk frame to an interface of an optical module; converting the optical signal into an electrical signal, performing electrical equalization and demodulation on the electrical signal, and recovering multi-lane data from the demodulated signal; aligning and rearranging the data on each lane, according to a lane sequence identifier included in an overhead frame header of the data on each lane; and recovering the OTUk frame according to the aligned and rearranged data. According to the present invention, lane rearrangement is performed by detecting the lane sequence identifier, and the recovery of the OTUk frame is achieved. Therefore, a training sequence overhead does not need to be additionally introduced, and the influence on the system performance is avoided.
    Type: Grant
    Filed: January 11, 2012
    Date of Patent: September 30, 2014
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Li Zeng, Chan Zhao, Changsong Xie