Patents by Inventor Liang Bangyuan Du
Liang Bangyuan Du 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: 9614617Abstract: An apparatus (104) mitigates cross-channel nonlinear distortion of an optical signal (138) carried on one of a plurality of wavelength channels (118) in a wavelength division multiplexed (WDM) transmission system (100). The apparatus includes a first optical receiver (126) which is arranged to detect a measure (134) of aggregate optical power of the plurality of wavelength channels. A nonlinear dispersion compensator includes means (144) for applying a phase modulation to the optical signal in proportion to the measure of aggregate optical power.Type: GrantFiled: October 6, 2010Date of Patent: April 4, 2017Assignee: Ofidium Pty. Ltd.Inventors: Arthur James Lowery, Liang Bangyuan Du
-
Patent number: 9294216Abstract: A method for transmitting digital information having a predetermined bit-rate (B) via a nonlinear optical channel includes determining a combination of transmission parameters comprising a number (N) of subcarriers, an information symbol rate (S) for each subcarrier, and a number (b) of bits per symbol on each subcarrier, such that B=NSb. An optical signal is generated comprising the plurality (N) of orthogonal optical subcarriers. Each subcarrier is modulated to carry a proportion (Sb/B) of the total bit-rate (B) of the digital information. The optical signal is then transmitted to a corresponding optical receiver via the nonlinear optical channel. The received signal has a measurable signal quality (Q) which is a function of the transmission parameters (N, S, b).Type: GrantFiled: March 2, 2012Date of Patent: March 22, 2016Assignee: OFIDIUM PTY. LTD.Inventors: Arthur James Lowery, Liang Bangyuan Du
-
Patent number: 9236951Abstract: An optical signal (116) is modulated with a transmitted electrical signal comprising an information-bearing component (122) and a pilot tone (120) having a predetermined frequency. Transmission of the signal results in distortion, including nonlinear optical transmission impairments. A method of receiving the signal includes detecting the optical signal to produce a received electrical signal (X) comprising a distorted variant of the transmitted electrical signal. The pilot tone is extracted from the received electrical signal using a filtering operation (308) having a predetermined characteristic, and a compensation signal determined based upon the extracted pilot tone. The compensation signal is applied to the received electrical signal (X) to produce a compensated signal (Y) having reduced distortion.Type: GrantFiled: December 19, 2011Date of Patent: January 12, 2016Assignee: OFIDIUM PTY. LTD.Inventors: Arthur James Lowery, Liang Bangyuan Du
-
Patent number: 9002210Abstract: An equalizer (200) for equalization of a signal transmitted via an optical fiber link from a transmitter to a corresponding receiver employs a backpropagation model (300) which comprises one or more sequential segments collectively representing an inverse fiber link. Each sequential segment comprises a linear backpropagation element (304), and a non-linear backpropagation element (306) having an associated compensation bandwidth (312). The equalizer (200) generates a distortion-mitigated signal by computing, for each sequential segment in turn, a first linear compensated signal from a signal input to the segment in accordance with the linear backpropagation element (304), and a non-linear compensated signal from the first linear compensated signal in accordance with the non-linear backpropagation element (306).Type: GrantFiled: March 1, 2011Date of Patent: April 7, 2015Assignee: Ofidium Pty. Ltd.Inventors: Arthur James Lowery, Liang Bangyuan Du
-
Publication number: 20140294393Abstract: A method for transmitting digital information having a predetermined bit-rate (B) via a nonlinear optical channel includes determining a combination of transmission parameters comprising a number (N) of subcarriers, an information symbol rate (S) for each subcarrier, and a number (b) of bits per symbol on each subcarrier, such that B=NSb. An optical signal is generated comprising the plurality (N) of orthogonal optical subcarriers. Each subcarrier is modulated to carry a proportion (Sb/B) of the total bit-rate (B) of the digital information. The optical signal is then transmitted to a corresponding optical receiver via the nonlinear optical channel. The received signal has a measurable signal quality (Q) which is a function of the transmission parameters (N, S, b).Type: ApplicationFiled: March 2, 2012Publication date: October 2, 2014Applicant: Ofidium Pty Ltd.Inventors: Arthur James Lowery, Liang Bangyuan Du
-
Publication number: 20140286642Abstract: An optical signal (116) is modulated with a transmitted electrical signal comprising an information-bearing component (122) and a pilot tone (120) having a predetermined frequency. Transmission of the signal results in distortion, including nonlinear optical transmission impairments. A method of receiving the signal includes detecting the optical signal to produce a received electrical signal (X) comprising a distorted variant of the transmitted electrical signal. The pilot tone is extracted from the received electrical signal using a filtering operation (308) having a predetermined characteristic, and a compensation signal determined based upon the extracted pilot tone. The compensation signal is applied to the received electrical signal (X) to produce a compensated signal (Y) having reduced distortion.Type: ApplicationFiled: December 19, 2011Publication date: September 25, 2014Applicant: Ofidium Pty LtdInventors: Arthur James Lowery, Liang Bangyuan Du
-
Patent number: 8655177Abstract: A method of generating an information-bearing optical signal (614) from input digital information (602) includes generating (604, 606) an information-bearing electrical signal comprising an in-phase (I) component and a quadrature (Q) component. Each of the components has a predetermined baseband bandwidth requirement (B). The I and Q signal components are combined (610) with corresponding I and Q components of a radio frequency (RF) carrier (608). The carrier has a central frequency greater than the signal bandwidth requirement (B). An optical source is modulated (612) with the combined I and Q signal and carrier components, in order to produce a modulated optical signal (614) which comprises an optical carrier corresponding with the RF carrier, and substantially only a single information-bearing optical sideband in an optical frequency domain, corresponding with the information-bearing electrical signals. Transmitters implementing the method are also disclosed.Type: GrantFiled: February 27, 2009Date of Patent: February 18, 2014Assignee: Ofidium Pty. Ltd.Inventors: Arthur James Lowery, Liang Bangyuan Du
-
Publication number: 20130156443Abstract: An equaliser (200) for equalisation of a signal transmitted via an optical fibre link from a transmitter to a corresponding receiver employs a backpropagation model (300) which comprises one or more sequential segments collectively representing an inverse fibre link. Each sequential segment comprises a linear backpropagation element (304), and a non-linear backpropagation element (306) having an associated compensation bandwidth (312). The equaliser (200) generates a distortion-mitigated signal by computing, for each sequential segment in turn, a first linear compensated signal from a signal input to the segment in accordance with the linear backpropagation element (304), and a non-linear compensated signal from the first linear compensated signal in accordance with the non-linear backpropagation element (306).Type: ApplicationFiled: March 1, 2011Publication date: June 20, 2013Applicant: OFIDIUM PTY LTDInventors: Arthur James Lowery, Liang Bangyuan Du
-
Publication number: 20120263461Abstract: An apparatus (104) mitigates cross-channel nonlinear distortion of an optical signal (138) carried on one of a plurality of wavelength channels (118) in a wavelength division multiplexed (WDM) transmission system (100). The apparatus includes a first optical receiver (126) which is arranged to detect a measure (134) of aggregate optical power of the plurality of wavelength channels. A nonlinear dispersion compensator includes means (144) for applying a phase modulation to the optical signal in proportion to the measure of aggregate optical power.Type: ApplicationFiled: October 6, 2010Publication date: October 18, 2012Applicant: Ofidium Pty LtdInventors: Arthur James Lowery, Liang Bangyuan Du
-
Patent number: 8112001Abstract: A method of transmitting information over a non-linear optical channel includes the step (152) of generating an information-bearing signal, preferably an OFDM signal, which includes a plurality of closely-spaced sub-carriers in the frequency domain. A time-varying phase modulation is determined (154), which is a first function, and preferably a linear function, of the transmitted optical power corresponding with the information-bearing signal. The information-bearing signal and the time-varying phase modulation are applied (156) to an optical source in order to generate a corresponding transmitted optical signal having substantially the stated transmitted optical power characteristic. The first function of transmitted optical power is selected so as to mitigate the effect of the non-linearity of the optical channel upon the transmitted optical signal.Type: GrantFiled: December 20, 2007Date of Patent: February 7, 2012Assignee: Ofidium Pty, Ltd.Inventors: Arthur James Lowery, Liang Bangyuan Du
-
Publication number: 20110286747Abstract: A method of generating an information-bearing optical signal (614) from input digital information (602) includes generating (604, 606) an information-bearing electrical signal comprising an in-phase (I) component and a quadrature (Q) component. Each of the components has a predetermined baseband bandwidth requirement (B). The I and Q signal components are combined (610) with corresponding I and Q components of a radio frequency (RF) carrier (608). The carrier has a central frequency greater than the signal bandwidth requirement (B). An optical source is modulated (612) with the combined I and Q signal and carrier components, in order to produce a modulated optical signal (614) which comprises an optical carrier corresponding with the RF carrier, and substantially only a single information-bearing optical sideband in an optical frequency domain, corresponding with the information-bearing electrical signals. Transmitters implementing the method are also disclosed.Type: ApplicationFiled: February 27, 2009Publication date: November 24, 2011Applicant: OFIDIUM PTY LTDInventors: Arthur James Lowery, Liang Bangyuan Du
-
Publication number: 20100247099Abstract: A method of transmitting information over a non-linear optical channel includes the step (152) of generating an information-bearing signal, preferably an OFDM signal, which includes a plurality of closely-spaced sub-carriers in the frequency domain. A time-varying phase modulation is determined (154), which is a first function, and preferably a linear function, of the transmitted optical power corresponding with the information-bearing signal. The information-bearing signal and the time-varying phase modulation are applied (156) to an optical source in order to generate a corresponding transmitted optical signal having substantially the stated transmitted optical power characteristic. The first function of transmitted optical power is selected so as to mitigate the effect of the non-linearity of the optical channel upon the transmitted optical signal.Type: ApplicationFiled: December 20, 2007Publication date: September 30, 2010Applicant: OFIDIUM PTY LTDInventors: Arthur Lowery, Liang Bangyuan Du