Patents by Inventor Marco Secondini

Marco Secondini has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10291331
    Abstract: A digital signal processing, DSP, unit (10) for use in a coherent optical receiver for an optical communications network. The DSP unit comprises an adaptive equalizer (12) and a processing block (22). The equalizer (12) comprises input ports for receiving electrical signals, each corresponding to a different state of polarization of an optical signal received by the coherent optical receiver, and output ports, each connected to a processing branch (14). A processing branch comprises a symbol sequence estimator, SSE, (16) and a carrier phase estimator, CPE, (18) comprising an input for receiving signal taped from an output of the processing branch. An output of the CPE is connected to a phase adjuster (20) interconnecting the respective output port of the equalizer and the SSE. The processing block (22) is connected to an output of the CPE, an output of the processing branch and at least one of the output of the phase adjuster and the outputs of the equalizer.
    Type: Grant
    Filed: February 9, 2015
    Date of Patent: May 14, 2019
    Assignee: Telefonaktiebolaget LM Ericsson (Publ)
    Inventors: Fabio Cavaliere, Marco Secondini
  • Publication number: 20180254833
    Abstract: A method of transmitting communications traffic, the method comprising steps of receiving a sequence of communications traffic bits; and mapping the sequence of communications traffic bits onto a respective one of a plurality of transmission symbols for transmission during a symbol time. Each transmission symbol is identified by a respective first symbol identifier indicative of a respective one or more of a plurality, M, of wavelengths for a transmission signal and a respective second symbol identifier indicative of a respective one or more of a plurality, N, of optical fibres on which to transmit the transmission signal.
    Type: Application
    Filed: September 8, 2015
    Publication date: September 6, 2018
    Inventors: Fabio CAVALIERE, Antonio MALACARNE, Enrico FORESTIERI, Marco SECONDINI, Luca POTI
  • Patent number: 9941963
    Abstract: A method (10) of non-linear propagation impairment equalization, the method comprising the steps of: a. receiving (12) communications traffic carried by an optical communications signal transmitted over an optical communications link; b. generating (14) a time dependent filter representation of a nonlinear time-variant impulse response of the inverse of the optical communications link; and c. applying (16) the time dependent filter representation to the received communications traffic to form non-linear propagation impairment equalized communications traffic. An optical communications link nonlinear propagation impairment equalizer and optical communications signal receiver apparatus are also provided.
    Type: Grant
    Filed: May 12, 2014
    Date of Patent: April 10, 2018
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Roberto Magri, Enrico Forestieri, Marco Secondini, Domenico Marsella
  • Publication number: 20170338893
    Abstract: A digital signal processing, DSP, unit (10) for use in a coherent optical receiver for an optical communications network. The DSP unit comprises an adaptive equaliser (12) and a processing block (22). The equaliser (12) comprises input ports for receiving electrical signals, each corresponding to a different state of polarization of an optical signal received by the coherent optical receiver,and output ports,each connected to a processing branch (14). A processing branch comprises a symbol sequence estimator, SSE, (16) and a carrier phase estimator, CPE, (18) comprising an input for receiving signal taped from an output of the processing branch. An output of the CPE is connected to a phase adjuster (20) interconnecting the respective output port of the equaliser and the SSE. The processing block (22) is connected to an output of the CPE,an output of the processing branch and at least one of the output of the phase adjuster and the outputs of the equalizer.
    Type: Application
    Filed: February 9, 2015
    Publication date: November 23, 2017
    Inventors: Fabio Cavaliere, Marco Secondini
  • Publication number: 20170078023
    Abstract: A method (10) of non-linear propagation impairment equalisation, the method comprising the steps of: a. receiving (12) communications traffic carried by an optical communications signal transmitted over an optical communications link; b. generating (14) a time dependent filter representation of a nonlinear time-variant impulse response of the inverse of the optical communications link; and c. applying (16) the time dependent filter representation to the received communications traffic to form non-linear propagation impairment equalised communications traffic. An optical communications link nonlinear propagation impairment equaliser and optical communications signal receiver apparatus are also provided.
    Type: Application
    Filed: May 12, 2014
    Publication date: March 16, 2017
    Inventors: Roberto MAGRI, Enrico FORESTIERI, Marco SECONDINI, Domenico MARSELLA
  • Patent number: 9490931
    Abstract: A muxponder comprising: modulation format conversion apparatus comprising: first and second inputs each arranged to receive an amplitude modulated tributary optical signal carrying a communications traffic bit stream; first and second optical to electrical signal conversion apparatus each arranged to receive a respective tributary optical signal and to convert it into a corresponding tributary electrical signal carrying the communications traffic bit stream; a delay element arranged to synchronize the communications traffic bit streams; and an optical IQ modulator arranged to receive an optical carrier signal and the tributary electrical signals. The optical IQ modulator having an in-phase arm and a quadrature arm, each arm being arranged to receive one of the tributary electrical signals such that each tributary electrical signal drives the respective arm of the optical IQ modulator to encode the communications traffic bit streams onto the optical carrier signal in a multilevel modulation format.
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: November 8, 2016
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Fabio Cavaliere, Gianluca Meloni, Marco Secondini, Luca Poti
  • Patent number: 9485030
    Abstract: A 2n-QAM (e.g. 16-QAM) optical modulator comprising cascaded I-Q modulators. The first I-Q modulator applies 2n-2 (e.g. 4) QAM to an optical signal, having a constellation diagram with the 2n-2 (e.g., 4) constellation points located in quadrant I. The second I-Q modulator subsequently applies a quaternary phase-shift keying (QPSK) modulation scheme to the optical signal, thereby rotating the constellation points of the 2n-2-QAM modulation scheme to quadrants II, III and IV, to produce a 2n-QAM modulation constellation diagram. The rotation causes the 2n-QAM modulator to inherently apply four quadrant differential encoding to the optical signal. A method of 2n-QAM optical modulation is also provided and optical signal transmission apparatus comprising the 2n-QAM optical modulator.
    Type: Grant
    Filed: October 28, 2014
    Date of Patent: November 1, 2016
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (publ)
    Inventors: Marco Secondini, Fabio Cavaliere
  • Patent number: 9432128
    Abstract: A method of detecting a signal in an optical receiver is described. The method includes converting a received optical signal to a digital electrical signal comprising a plurality of samples, applying a predetermined phase rotation to said samples to obtain amplitude and phase components of phase range adjusted sample values, and performing a first detection process based on the amplitude and phase components of the phase range adjusted sample values.
    Type: Grant
    Filed: July 25, 2012
    Date of Patent: August 30, 2016
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Domenico Marsella, Marco Secondini, Roberto Magri, Enrico Forestieri
  • Publication number: 20160065325
    Abstract: A muxponder comprising: modulation format conversion apparatus comprising: first and second inputs each arranged to receive an amplitude modulated tributary optical signal carrying a communications traffic bit stream; first and second optical to electrical signal conversion apparatus each arranged to receive a respective tributary optical signal and to convert it into a corresponding tributary electrical signal carrying the communications traffic bit stream; a delay element arranged to synchronise the communications traffic bit streams; and an optical IQ modulator arranged to receive an optical carrier signal and the tributary electrical signals. The optical IQ modulator having an in-phase arm and a quadrature arm, each arm being arranged to receive one of the tributary electrical signals such that each tributary electrical signal drives the respective arm of the optical IQ modulator to encode the communications traffic bit streams onto the optical carrier signal in a multilevel modulation format.
    Type: Application
    Filed: December 22, 2011
    Publication date: March 3, 2016
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Fabio Cavaliere, Gianluca Meloni, Marco Secondini, Luca Poti
  • Patent number: 9166703
    Abstract: An equalizer (60) processes, in the electrical domain, a signal obtained from a path of an optical transmission system. The equalizer comprises N cascaded stages (where N?1). At least one of the stages comprises a cascade of a linear equalization element (61) and a non-linear equalization element (62). The equalizer (60) is able to compensate for both linear impairments, such as dispersion, and non-linear impairments. The cascaded linear and non-linear elements can simulate the effect of signal propagation through a fiber which has the opposite propagation parameters (e.g. attenuation, dispersion, non-linearity) to those of the propagation path experienced by a signal in the transmission system. The non-linear equalization element (62) can be a non-linear phase rotator which rotates phase of an input signal proportional to the squared modulus of the input signal amplitude.
    Type: Grant
    Filed: February 20, 2009
    Date of Patent: October 20, 2015
    Assignee: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Marco Secondini, Enrico Forestieri
  • Publication number: 20150180588
    Abstract: A method of detecting a signal in an optical receiver is described. The method includes converting a received optical signal to a digital electrical signal comprising a plurality of samples, applying a predetermined phase rotation to said samples to obtain amplitude and phase components of phase range adjusted sample values, and performing a first detection process based on the amplitude and phase components of the phase range adjusted sample values.
    Type: Application
    Filed: July 25, 2012
    Publication date: June 25, 2015
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Domenico Marsella, Marco Secondini, Roberto Magri, Enrico Forestieri
  • Publication number: 20150125161
    Abstract: A 2n-QAM (e.g. 16-QAM) optical modulator comprising cascaded I-Q modulators. The first I-Q modulator applies 2n-2 (e.g. 4) QAM to an optical signal, having a constellation diagram with the 2n-2 (e.g., 4) constellation points located in quadrant I. The second I-Q modulator subsequently applies a quaternary phase-shift keying (QPSK) modulation scheme to the optical signal, thereby rotating the constellation points of the 2n-2-QAM modulation scheme to quadrants II, III and IV, to produce a 2n-QAM modulation constellation diagram. The rotation causes the 2n-QAM modulator to inherently apply four quadrant differential encoding to the optical signal. A method of 2n-QAM optical modulation is also provided and optical signal transmission apparatus comprising the 2n-QAM optical modulator.
    Type: Application
    Filed: October 28, 2014
    Publication date: May 7, 2015
    Inventors: Marco Secondini, Fabio Cavaliere
  • Patent number: 8903253
    Abstract: A 2n-QAM (e.g. 16-QAM) optical modulator comprising cascaded I-Q modulators. The first I-Q modulator applies 2n?2 (e.g. 4) QAM to an optical signal, having a constellation diagram with the 2n?2 (e.g., 4) constellation points located in quadrant I. The second I-Q modulator subsequently applies a quaternary phase-shift keying (QPSK) modulation scheme to the optical signal, thereby rotating the constellation points of the 2n?2-QAM modulation scheme to quadrants II, III and IV, to produce a 2n-QAM modulation constellation diagram. The rotation causes the 2n-QAM modulator to inherently apply four quadrant differential encoding to the optical signal. A method of 2n-QAM optical modulation is also provided and optical signal transmission apparatus comprising the 2n-QAM optical modulator.
    Type: Grant
    Filed: September 8, 2008
    Date of Patent: December 2, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Marco Secondini, Fabio Cavaliere
  • Patent number: 8611763
    Abstract: A method (10) of compensating phase noise in a coherent optical communications network. The method comprises: receiving a traffic sample (12); receiving an optical carrier and determining a phase noise estimate for the optical carrier (14); and removing the phase noise estimate from the traffic sample to form a phase noise compensated traffic sample (16).
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: December 17, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Marco Secondini, Tommaso Foggi, Giulio Colavolpe, Gianluca Meloni, Luca Poti, Enrico Forestieri
  • Publication number: 20120027404
    Abstract: A method (10) of compensating phase noise in a coherent optical communications network. The method comprises: receiving a traffic sample (12); receiving an optical carrier and determining a phase noise estimate for the optical carrier (14); and removing the phase noise estimate from the traffic sample to form a phase noise compensated traffic sample (16).
    Type: Application
    Filed: September 2, 2010
    Publication date: February 2, 2012
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Marco Secondini, Tommaso Foggi, Giulio Colavolpe, Gianluca Meloni, Luca Poti, Enrico Forestieri
  • Publication number: 20120027418
    Abstract: An equaliser (60) processes, in the electrical domain, a signal obtained from a path of an optical transmission system. The equaliser comprises N cascaded stages (where N?1). At least one of the stages comprises a cascade of a linear equalisation element (61) and a non-linear equalisation element (62). The equaliser (60) is able to compensate for both linear impairments, such as dispersion, and non-linear impairments. The cascaded linear and non-linear elements can simulate the effect of signal propagation through a fibre which has the opposite propagation parameters (e.g. attenuation, dispersion, non-linearity) to those of the propagation path experienced by a signal in the transmission system. The non-linear equalisation element (62) can be a non-linear phase rotator which rotates phase of an input signal proportional to the squared modulus of the input signal amplitude.
    Type: Application
    Filed: February 20, 2009
    Publication date: February 2, 2012
    Applicant: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Marco Secondini, Enrico Forestieri
  • Publication number: 20110182590
    Abstract: A 2n-QAM (e.g. 16-QAM) optical modulator comprising cascaded I-Q modulators. The first I-Q modulator applies 2n?2 (e.g. 4) QAM to an optical signal, having a constellation diagram with the 2n?2 (e.g., 4) constellation points located in quadrant I. The second I-Q modulator subsequently applies a quaternary phase-shift keying (QPSK) modulation scheme to the optical signal, thereby rotating the constellation points of the 2n?2-QAM modulation scheme to quadrants II, III and IV, to produce a 2n-QAM modulation constellation diagram. The rotation causes the 2n-QAM modulator to inherently apply four quadrant differential encoding to the optical signal. A method of 2n-QAM optical modulation is also provided and optical signal transmission apparatus comprising the 2n-QAM optical modulator.
    Type: Application
    Filed: September 8, 2008
    Publication date: July 28, 2011
    Inventors: Marco Secondini, Fbio Cavalieri
  • Patent number: 7873282
    Abstract: A polarization multiplex transmission system (10) comprises two optical signals (z1, z2) transmitted over the same optical fiber (15) at the same wavelength but with orthogonal polarizations. The system is characterized by receiving apparatus (10) which is operable to filter the two components with orthogonal polarization of the signal received in accordance with an appropriate transfer matrix which is dynamically controlled on the basis of the output signals in such a manner as to approximate the reverse transfer matrix of the fiber in the region of the spectrum occupied by the signal so as to compensate for Polarization Mode Dispersion (PMD) and polarization rotation introduced by the fiber and eliminating distortion and mutual interference effects for both the signals and thereby obtain a demultiplexed output corresponding to the two transmitted signals.
    Type: Grant
    Filed: March 9, 2005
    Date of Patent: January 18, 2011
    Assignee: Ericsson AB
    Inventors: Marco Secondini, Enrico Forestieri, Giancarlo Prati, Giulio Colavolpe
  • Publication number: 20080159741
    Abstract: A polarization multiplex transmission system (10) comprises two optical signals (z1, z2) transmitted over the same optical fibre (15) at the same wavelength but with orthogonal polarizations. The system is characterised by receiving apparatus (10) which is operable to filter the two components with orthogonal polarization of the signal received in accordance with an appropriate transfer matrix which is dynamically controlled on the basis of the output signals in such a manner as to approximate the reverse transfer matrix of the fibre in the region of the spectrum occupied by the signal so as to compensate for Polarization Mode Dispersion (PMD) and polarization rotation introduced by the fibre and eliminating distortion and mutual interference effects for both the signals and thereby obtain a demultiplexed output corresponding to the two transmitted signals.
    Type: Application
    Filed: March 9, 2005
    Publication date: July 3, 2008
    Inventors: Marco Secondini, Enrico Forestieri, Giancarlo Prati, Giulio Colavolpe