Patents by Inventor Mu Xu

Mu Xu 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: 12035083
    Abstract: An integrated transceiver is provided for a coherent optical communication network. The integrated transceiver includes a first optical transceiver portion configured to receive and transmit coherent optical signals from and to the coherent optical communication network, respectively. The integrated transceiver further includes a second optical transceiver portion configured to receive and transmit non-coherent optical signals respectively from and to a non-coherent optical communication network. The integrated transceiver further includes an integrated media access control (MAC) processor disposed between the first and second optical transceiver portions.
    Type: Grant
    Filed: October 18, 2021
    Date of Patent: July 9, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Zhensheng Jia, Mu Xu, Luis Alberto Campos, Curtis Dean Knittle
  • Patent number: 11996893
    Abstract: An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.
    Type: Grant
    Filed: January 2, 2023
    Date of Patent: May 28, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Junwen Zhang, Zhensheng Jia, Luis Alberto Campos, Haipeng Zhang, Mu Xu, Jing Wang, Curtis Dean Knittle, Chuang Zhou
  • Patent number: 11990937
    Abstract: An echo cancellation method includes steps of (a) extracting phase-distortion estimates, (b) reconstructing an echo signal, (c) generating a clean signal, and (d) producing a primary signal. Step (a) includes extracting, from a first phase signal, a plurality of phase-distortion estimates, the first phase signal having been estimated from an echo-corrupted signal received at a first coherent transceiver of a coherent optical network. Step (b) includes reconstructing an echo signal from the plurality of phase-distortion estimates and a transmitted signal transmitted by the first coherent transceiver. Step (c) includes generating a clean signal as a difference between the reconstructed echo signal and the first phase signal. Step (d) includes producing a primary signal by mapping each of a plurality of clean-phase estimates of the clean signal to one of a plurality of constellation symbols associated with a modulation scheme of the primary signal.
    Type: Grant
    Filed: August 22, 2022
    Date of Patent: May 21, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Mu Xu, Zhensheng Jia, Junwen Zhang, Haipeng Zhang, Luis Alberto Campos
  • Patent number: 11990944
    Abstract: A method for generating optical communication signals in a communication network includes (1) generating at least a first optical tone and a second optical tone using a quantum dot (QD) coherent comb laser (CCL), the first and second optical tones having different respective wavelengths, (2) modulating the first optical tone according to a first modulation signal to generate a first communication signal, and (3) modulating the second optical tone according to a second modulation signal to generate a second communication signal.
    Type: Grant
    Filed: February 10, 2022
    Date of Patent: May 21, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Haipeng Zhang, Mu Xu, Zhensheng Jia, Luis Alberto Campos
  • Patent number: 11984928
    Abstract: A method for estimating a chromatic dispersion of an optical-fiber channel is disclosed includes receiving, via the optical-fiber channel, a chromatically-dispersed signal having a symbol rate 1/T. The method also includes, for each chromatic-dispersion value of a plurality of chromatic-dispersion values, determining a respective clock-tone magnitude by: (i) applying, to the chromatically-dispersed signal or a signal derived therefrom, a chromatic dispersion equal to the chromatic-dispersion value to generate a dispersion-compensated signal, and (ii) extracting the clock-tone magnitude from at least one of a positive-frequency clock-tone and a negative-frequency clock-tone of the dispersion-compensated signal, the positive-frequency clock-tone and the negative-frequency clock-tone being spectral components of the dispersion-compensated signal at temporal frequencies 1/T or ?1/T respectively. The method also includes determining a maximum of the extracted clock-tone magnitudes.
    Type: Grant
    Filed: January 26, 2022
    Date of Patent: May 14, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Junwen Zhang, Zhensheng Jia, Mu Xu, Haipeng Zhang, Luis Alberto Campos
  • Patent number: 11898900
    Abstract: A method for distributed fiber optic sensing (DFOS) includes (a) generating first data signals for transmission via a first fiber optic strand, (b) generating first sensing signals for transmission via the first fiber optic strand, and (c) analyzing at least one of first back-scattering signals and first forward-scattering signals of the first sensing signals, to perform DFOS. The method may further include generating the first sensing signal such that presence of the first sensing signal on the first fiber optic strand does not interfere with transmission of the first data signal by the first fiber optic strand.
    Type: Grant
    Filed: February 25, 2022
    Date of Patent: February 13, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Luis Alberto Campos, Zhensheng Jia, Mu Xu, Haipeng Zhang, Belal Hamzeh
  • Patent number: 11888525
    Abstract: A full duplex communication network includes an optical transmitter end having a first coherent optics transceiver, an optical receiver end having a second coherent optics transceiver, and an optical transport medium operably coupling the first coherent optics transceiver to the second coherent optics transceiver. The first coherent optics transceiver is configured to simultaneously transmit a downstream optical signal and receive an upstream optical signal. The second coherent optics transceiver is configured to simultaneously receive the downstream optical signal from the first coherent optics transceiver and transmit the upstream optical signal first coherent optics transceiver. At least one of the downstream optical signal and the upstream optical signal includes at least one coherent optical carrier and at least one non-coherent optical carrier.
    Type: Grant
    Filed: February 8, 2021
    Date of Patent: January 30, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Zhensheng Jia, Luis Alberto Campos, Jing Wang, Mu Xu, Haipeng Zhang, Curtis Dean Knittle
  • Patent number: 11889369
    Abstract: A method is provided for initiating a handover of a wireless device from a first node to a second node in a communication network. The method includes steps of (a) obtaining, at a first time, a (i) speed, (ii) direction, and (iii) first location of the wireless device, (b) determining, relative to the first location, a first signal strength of the second node and a second, higher signal strength of a third node different from the second node, (c) estimating, based on the obtained (i) first location, (ii) speed, and (iii) direction, a second location for the wireless device at a second, subsequent time, (d) confirming that the second location is within a transmission range of the second node, and (e) preempting the handover to the third node by performing, prior to the second time, the handover directly from the first node to the second node.
    Type: Grant
    Filed: November 12, 2021
    Date of Patent: January 30, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Omkar Shripad Dharmadhikari, Mu Xu, Bernardo Huberman
  • Patent number: 11882316
    Abstract: An optical network includes a transmitting portion configured to (i) encode an input digitized sequence of data samples into a quantized sequence of data samples having a first number of digits per sample, (ii) map the quantized sequence of data samples into a compressed sequence of data samples having a second number of digits per sample, the second number being lower than the first number, and (iii) modulate the compressed sequence of data samples and transmit the modulated sequence over a digital optical link. The optical network further includes a receiving portion configured to (i) receive and demodulate the modulated sequence from the digital optical link, (ii) map the demodulated sequence from the second number of digits per sample into a decompressed sequence having the first number of digits per sample, and (iii) decode the decompressed sequence.
    Type: Grant
    Filed: June 13, 2022
    Date of Patent: January 23, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Zhensheng Jia, Luis Alberto Campos, Mu Xu, Jing Wang
  • Patent number: 11881899
    Abstract: A receiver is provided for processing an input signal from a communication network. The receiver includes a processor and a memory configured to store computer executable instructions, which, when executed by the processor, cause the processor to (i) receive an input data signal including digital bit information, (ii) code the input data signal into a plurality of multi-level symbols, (iii) map the plurality of multi-level symbols into a plurality of constellation points in the phase domain, (iv) execute a first phase recovery subprocess on the plurality of constellation points to recover a first carrier phase of the input signal, (v) implement a Gaussian mixture model (GMM) on the recovered first carrier phase to generate an enhanced recovered carrier phase, and (vi) process the enhanced recovered carrier phase with a second phase recovery subprocess to reduce distortion from the input signal.
    Type: Grant
    Filed: May 27, 2022
    Date of Patent: January 23, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Haipeng Zhang, Mu Xu, Zhensheng Jia, Luis Alberto Campos
  • Patent number: 11863297
    Abstract: A digital receiver is configured to process a polarization multiplexed carrier from a communication network. The polarization multiplexed carrier includes a first polarization and a second polarization. The receiver includes a first lane for transporting a first input signal of the first polarization, a second lane for transporting a second input signal of the second polarization, a dynamic phase noise estimation unit disposed within the first lane and configured to determine a phase noise estimate of the first input signal, a first carrier phase recovery portion configured to remove carrier phase noise from the first polarization based on a combination of the first input signal and a function of the determined phase noise estimate, and a second carrier phase recovery portion configured to remove carrier phase noise from the second polarization based on a combination of the second input signal and the function of the determined phase noise estimate.
    Type: Grant
    Filed: July 11, 2022
    Date of Patent: January 2, 2024
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Junwen Zhang, Zhensheng Jia, Mu Xu, Haipeng Zhang, Luis Alberto Campos, Curtis Dean Knittle
  • Patent number: 11855694
    Abstract: An optical communication network includes a primary laser source, a first comb generator, and a first transceiver. The first comb generate a first plurality of comb tones having constant frequency spacing. The first transceiver includes a first transmitter having a secondary laser with a resonator frequency injection locked to a frequency of a single longitudinal mode corresponding to a particular comb tone of the first plurality of comb tones. The first transmitter adheres input data onto the injection locked frequency, and outputs a modulated data stream over an optical transport to a second transceiver downstream of the first transceiver. The improvement includes a second comb generator disposed downstream of, receives a seed tone from, and is phase-synchronized with, the first comb generator. The second comb generator outputs a second plurality of comb tones substantially conforming to the frequencies and frequency spacing of the first plurality of comb tones.
    Type: Grant
    Filed: November 15, 2021
    Date of Patent: December 26, 2023
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Haipeng Zhang, Mu Xu, Junwen Zhang, Zhensheng Jia, Luis Alberto Campos
  • Publication number: 20230361879
    Abstract: An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.
    Type: Application
    Filed: January 2, 2023
    Publication date: November 9, 2023
    Inventors: Junwen Zhang, Zhensheng Jia, Luis Alberto Campos, Haipeng Zhang, Mu Xu, Jing Wang, Curtis Dean Knittle, Chuang Zhou
  • Patent number: 11804905
    Abstract: An optical full-field transmitter (OFFT) includes a plurality of optical circulators and a polarization beam combiner. The plurality of optical circulators are fabricated on a silicon-on-insulator (SOI) substrate, where each of the optical circulators has (a) a first port that optically couples to a high-quality optical source, (b) a second port that optically couples to a child laser configured to receive amplitude modulation data, and (c) a third port optically coupled to a phase modulator that (i) is configured to receive a phase modulation data and (ii) includes an output port that outputs amplitude and phase modulated light. The polarization beam combiner receives the amplitude and phase modulated light from each of the optical circulators and outputs combined amplitude and phase modulated light.
    Type: Grant
    Filed: March 7, 2022
    Date of Patent: October 31, 2023
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Haipeng Zhang, Mu Xu, Zhensheng Jia, Junwen Zhang, Luis Alberto Campos
  • Patent number: 11804904
    Abstract: A beam steering subsystem is provided in an optical communication system. The beam steering subsystem is configured for steering a free-space optical (FSO) beam from a first transceiver to a second transceiver disposed remotely from the first receiver. The beam steering subsystem includes a beam steering device disposed between the first transceiver and the second transceiver, and an optical tracking unit in optical communication and electrical communication with the beam steering device. The wherein the beam steering device is further configured to (i) receive the FSO beam from the first transceiver, (ii) receive an optical tracking signal from the second transceiver, (iii) optically relay the received optical tracking signal to the optical tracking unit, and (iv) steer the FSO beam to the second transceiver based on an electrical feedback control signal from optical tracking unit.
    Type: Grant
    Filed: July 23, 2021
    Date of Patent: October 31, 2023
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Haipeng Zhang, Zhensheng Jia, Junwen Zhang, Mu Xu, Luis Alberto Campos
  • Patent number: 11784719
    Abstract: A method for tuning a power characteristic of an optical frequency comb includes controlling a modulating light source according to a plurality of modulation parameters to generate an optical frequency comb including a plurality of optical tones. Additionally, at least one of the plurality of modulation parameters is changed until a total power of the plurality of optical tones is greater than or equal to a minimum threshold value. Furthermore, at least one of the plurality of modulation parameters are changed until respective powers of each of the plurality of optical tones are within a predetermined proximity to respective target powers of each of the plurality of optical tones.
    Type: Grant
    Filed: April 1, 2021
    Date of Patent: October 10, 2023
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Lin Cheng, Luis Alberto Campos, Haipeng Zhang, Junwen Zhang, Mu Xu, Zhensheng Jia
  • Patent number: 11770204
    Abstract: A coherent passive optical network includes a downstream transceiver and first and second upstream transceivers in communication with an optical transport medium. The downstream transceiver includes a downstream processor for mapping a downstream data stream to a plurality of sub-bands, and a downstream transmitter for transmitting a downstream optical signal modulated with the plurality of sub-bands. The first upstream transceiver includes a first local oscillator (LO) for tuning a first LO center frequency to a first sub-band of the plurality of sub-bands, and a first downstream receiver for coherently detecting the downstream optical signal within the first sub-band. The second upstream transceiver includes a second downstream receiver configured for coherently detecting the downstream optical signal within a second sub-band of the plurality of sub-bands. The downstream processor dynamically allocates the first and second sub-bands to the first and second transceivers in the time and frequency domains.
    Type: Grant
    Filed: February 28, 2022
    Date of Patent: September 26, 2023
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Junwen Zhang, Zhensheng Jia, Mu Xu, Haipeng Zhang, Luis Alberto Campos
  • Patent number: 11757556
    Abstract: An optical communication network includes a downstream optical transceiver. The downstream optical transceiver includes at least one coherent optical transmitter configured to transmit a downstream coherent dual-band optical signal having a left-side band portion, a right-side band portion, and a central optical carrier disposed within a guard band between the left-side band portion and the right-side band portion. The network further includes an optical transport medium configured to carry the downstream coherent dual-band optical signal from the downstream optical transceiver. The network further includes at least one modem device operably coupled to the optical transport medium and configured to receive the downstream coherent dual-band optical signal from the optical transport medium. The at least one modem device includes a downstream coherent optical receiver, and a first slave laser injection locked to a frequency of the central optical carrier.
    Type: Grant
    Filed: May 26, 2022
    Date of Patent: September 12, 2023
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Mu Xu, Zhensheng Jia, Haipeng Zhang, Luis Alberto Campos
  • Patent number: 11750357
    Abstract: Coherent phase recovery method includes producing, with a transmit-side frequency-comb source, a first frequency-comb signal that includes a pilot tone and a first optical tone having a first center wavelength that differs from a pilot center wavelength of the pilot tone. The method also includes coherently modulating the first optical tone to yield a first modulated signal; and generating a second frequency-comb signal with a receive-side frequency-comb source driven by the pilot tone. The method also includes extracting, from the second frequency-comb signal, a first local-oscillator tone having the first center wavelength; and demodulating the first modulated signal by homodyning the first modulated signal with the first local-oscillator tone.
    Type: Grant
    Filed: April 7, 2021
    Date of Patent: September 5, 2023
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Haipeng Zhang, Luis Alberto Campos, Junwen Zhang, Mu Xu, Zhensheng Jia
  • Patent number: 11736199
    Abstract: A method for phase compensation in an optical communication network includes (1) modifying a modulated signal according to one or more correction factors to generate a compensated signal, to compensate for phase rotation, (2) modulating a magnitude of an optical signal in response to a magnitude of the compensated signal, and (3) modulating a phase of the optical signal, after modulating the magnitude of the optical signal, in response to a phase of the compensated signal.
    Type: Grant
    Filed: June 4, 2021
    Date of Patent: August 22, 2023
    Assignee: Cable Television Laboratories, Inc.
    Inventors: Junwen Zhang, Mu Xu, Haipeng Zhang, Zhensheng Jia, Luis Alberto Campos