Patents Assigned to Ofidium Pty., Ltd.
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Patent number: 9762323Abstract: A method (1200) of transmitting digital information via a nonlinear optical channel (722), comprises receiving (1202) data (702) comprising at least a portion of the digital information. A plurality of frequency domain symbols is generated (1204) from the data, and each symbol is assigned to one of a predetermined plural number of frequency sub-bands. Each sub-band may be processed separately (1206) to reduce a peak-to-average power ratio (PAPR) of a transmitted optical signal. The optical signal (12) is then generated (1208) comprising the plural number of sub-bands, and transmitted via the nonlinear optical channel (722). The plural number of frequency sub-bands is predetermined so as to reduce nonlinear optical distortion of the optical signal within the nonlinear optical channel relative to a corresponding single frequency band signal. A corresponding information-receiving method, a transmitter apparatus and a receiver apparatus are also disclosed.Type: GrantFiled: March 17, 2011Date of Patent: September 12, 2017Assignee: Ofidium Pty. Ltd.Inventor: William Shieh
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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
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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
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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
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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
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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
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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
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Patent number: 8699882Abstract: Methods and apparatus for generating and processing a signal are disclosed. The signal may comprise a plurality of mutually orthogonal subcarriers constituting a plurality of bands. The signal may be either an optical or a radio frequency signal.Type: GrantFiled: January 7, 2010Date of Patent: April 15, 2014Assignee: Ofidium Pty LtdInventor: William Shieh
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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
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Publication number: 20130195459Abstract: A method (1200) of transmitting digital information via a nonlinear optical channel (722), comprises receiving (1202) data (702) comprising at least a portion of the digital information. A plurality of frequency domain symbols is generated (1204) from the data, and each symbol is assigned to one of a predetermined plural number of frequency sub-bands. Each sub-band may be processed separately (1206) to reduce a peak-to-average power ratio (PAPR) of a transmitted optical signal. The optical signal (12) is then generated (1208) comprising the plural number of sub-bands, and transmitted via the nonlinear optical channel (722). The plural number of frequency sub-bands is predetermined so as to reduce nonlinear optical distortion of the optical signal within the nonlinear optical channel relative to a corresponding single frequency band signal. A corresponding information-receiving method, a transmitter apparatus and a receiver apparatus are also disclosed.Type: ApplicationFiled: March 17, 2011Publication date: August 1, 2013Applicant: Ofidium Pty Ltd.Inventor: William Shieh
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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
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Patent number: 8306435Abstract: A receiver for recovering transmitted information carried by a received optical signal that has been affected by dispersion includes an optical splitter having an input port arranged to receive the received optical signal, and a plurality of output ports. A proportion of optical power at the input port is transmitted to each of the output ports. A plurality of optical detectors is operably connected to respective output ports of the optical splitter, for generating a corresponding plurality of electrical signals. Optical phase shifters are disposed between the output ports of the optical splitter and respective optical detectors. As a result, each optical phase shifter applies a frequency dependent phase shift to an optical signal passing therethrough.Type: GrantFiled: February 15, 2008Date of Patent: November 6, 2012Assignee: Ofidium Pty, Ltd.Inventors: Jean Armstrong, Arthur Lowery
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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
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Patent number: 8233799Abstract: A method and apparatus for receiving digital information transmitted via an optical signal over an optical channel wherein the optical signal includes an optical carrier (402) and at least one information-bearing optical sideband (404) in the optical frequency domain. The transmitted optical power is distributed between the optical carrier (402) and the optical side band (404). The received optical signal is processed in order to increase the received power in the optical carrier (402) relative to the power in the optical side-band (404). The processed optical signal is detected in order to produce a corresponding electrical signal. The electrical signal is then processed in order to recover the digital information.Type: GrantFiled: October 15, 2008Date of Patent: July 31, 2012Assignee: Ofidium Pty, Ltd.Inventor: Arthur James Lowery
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Patent number: 8111993Abstract: A system (100) for transmitting digital information includes a transmitting apparatus (102) for generating an optical signal bearing digital information, a dispersive optical channel (104), and a receiving apparatus (110) for receiving the optical signal. The dispersive optical channel (104) is disposed to convey the optical signal from the transmitting apparatus (102) to the receiving apparatus (110). The transmitting apparatus includes an encoder (114) for encoding digital information into a series of blocks, each including a plurality of data symbols corresponding with one or more bits of digital information. A signal generator (118) generates a time-varying signal corresponding with each of said blocks.Type: GrantFiled: October 12, 2006Date of Patent: February 7, 2012Assignee: Ofidium Pty Ltd.Inventors: Arthur James Lowery, Jean Armstrong
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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
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Patent number: 8107827Abstract: An apparatus and method are provided for receiving an optical signal having an optical carrier component and at least one information-bearing optical sideband. In general, an optical filter arrangement (110) is used to separate the optical carrier component from the information-bearing optical sideband. First and second optical splitters (126, 128) divide the optical power in the optical carrier and the optical sideband, respectively, into corresponding sub-components. The sub-components of the optical carrier have substantially orthogonal polarisation states, which is an optional characteristic of the sideband sub-components. First and second optical coupling devices (142, 144) respectively each combine one of the optical carrier sub-components with a corresponding one of the optical sideband sub-components. Optical detectors (158, 160) detect the outputs of the combiners (142, 144).Type: GrantFiled: February 20, 2009Date of Patent: January 31, 2012Assignee: Ofidium Pty, Ltd.Inventors: Brendon James Schmidt, Arthur James Lowery, Jean Armstrong
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Patent number: 8107826Abstract: A method of communicating digital information over a dispersive optical channel includes encoding the digital information into a plurality of data blocks, each of which includes a number of bits of the information. A time-varying electrical signal is generated which corresponds with each of said data blocks. The time-varying electrical signal is applied to an optical transmitter (122) to generate an optical signal which includes an asymmetrically amplitude limited transmitted signal modulated onto an optical carrier. The optical signal is then transmitted over the dispersive optical channel (106). At a receiving apparatus (104) the optical signal is detected to produce an electrical signal which corresponds with the asymmetrically amplitude limited transmitted signal.Type: GrantFiled: September 1, 2006Date of Patent: January 31, 2012Assignee: Ofidium Pty Ltd.Inventors: Jean Armstrong, Arthur James Lowery
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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
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Publication number: 20110013914Abstract: A method and apparatus for receiving digital information transmitted via an optical signal over an optical channel wherein the optical signal includes an optical carrier (402) and at least one information-bearing optical sideband (404) in the optical frequency domain. The transmitted optical power is distributed between the optical carrier (402) and the optical side band (404). The received optical signal is processed in order to increase the received power in the optical carrier (402) relative to the power in the optical side-band (404). The processed optical signal is detected in order to produce a corresponding electrical signal. The electrical signal is then processed in order to recover the digital information.Type: ApplicationFiled: October 15, 2008Publication date: January 20, 2011Applicant: Ofidium Pty LtdInventor: Arthur James Lowery