Patents by Inventor Tung Trong Nguyen
Tung Trong Nguyen 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).
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Patent number: 11637638Abstract: A method at a receiver comprises receiving a signal conveying symbols at respective positions within a clock cycle, the symbols comprising a data set consisting of data symbols and a pilot set consisting of pilot symbols; determining detected phases of the symbols based on the signal; generating first phase estimates based on the detected phases of a subset of the pilot set, and reference phases of the subset of the pilot set, the first phase estimates being associated with the positions of the pilot set; and generating second phase estimates based on the detected phases of the pilot set, reference phases of the pilot set, and the first phase estimates, the second phase estimates being associated with the positions of the pilot set and of at least a subset of the data set; and applying rotations to the detected phases of the symbols based on the second phase estimates.Type: GrantFiled: December 7, 2021Date of Patent: April 25, 2023Assignee: CIENA CORPORATIONInventors: James St. Leger Harley, Tung Trong Nguyen, Timothy Creasy, Blake Toplis
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Patent number: 11451304Abstract: Upon receiving a communications signal conveying symbols at a symbol period T, a receiver applies filter coefficients to a digital representation of the communications signal, thereby generating filtered signals having a shape in the frequency domain characterized by a bandwidth expansion factor ?, where components of the filtered signals correspond to angular frequencies ? = - ? ? ( 1 + ? ) T ? ? … - ? ? ( 1 - ? ) T , + ? ? ( 1 - ? ) T ? ? … + ? ? ( 1 + ? ) T . The receiver calculates first-order components from a first phase derivative of the components at a first differential distance, second-order components from a second phase derivative of the first-order components at a second differential distance, and composite second-order components from an average of the second-order components over multiple time intervals.Type: GrantFiled: November 11, 2021Date of Patent: September 20, 2022Assignee: CIENA CORPORATIONInventors: Tung Trong Nguyen, Timothy James Creasy, Shahab Oveis Gharan
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Patent number: 11451367Abstract: A receiver generates a stream of digital samples from an analog electrical signal that represents data conveyed to the receiver over a communication channel, where the stream of digital samples comprises current samples corresponding to a current timepoint, previous samples corresponding to a timepoint earlier than the current timepoint, and subsequent samples corresponding to a timepoint later than the current timepoint. The receiver generates previous, current, and subsequent phase offset signals based on the previous, current, and subsequent samples, respectively. The receiver uses the previous phase offset signal to adjust clock frequency and clock phase of the current samples, thereby resulting in current adjusted samples. The receiver adjusts clock phase of the current adjusted samples based on any one of the previous, current, and subsequent phase offset signals. In some examples, receiver adjusts the clock phase of the current adjusted samples based on the subsequent phase offset signal.Type: GrantFiled: September 24, 2021Date of Patent: September 20, 2022Assignee: Ciena CorporationInventors: Shahab Oveis Gharan, James St. Leger Harley, Tung Trong Nguyen
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Publication number: 20220294538Abstract: A method at a receiver comprises receiving a signal conveying symbols at respective positions within a clock cycle, the symbols comprising a data set consisting of data symbols and a pilot set consisting of pilot symbols; determining detected phases of the symbols based on the signal; generating first phase estimates based on the detected phases of a subset of the pilot set, and reference phases of the subset of the pilot set, the first phase estimates being associated with the positions of the pilot set; and generating second phase estimates based on the detected phases of the pilot set, reference phases of the pilot set, and the first phase estimates, the second phase estimates being associated with the positions of the pilot set and of at least a subset of the data set; and applying rotations to the detected phases of the symbols based on the second phase estimates.Type: ApplicationFiled: December 7, 2021Publication date: September 15, 2022Applicant: CIENA CORPORATIONInventors: James St. Leger HARLEY, Tung Trong NGUYEN, Timothy CREASY, Blake TOPLIS
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Publication number: 20220294604Abstract: A receiver generates a stream of digital samples from an analog electrical signal that represents data conveyed to the receiver over a communication channel, where the stream of digital samples comprises current samples corresponding to a current timepoint, previous samples corresponding to a timepoint earlier than the current timepoint, and subsequent samples corresponding to a timepoint later than the current timepoint. The receiver generates previous, current, and subsequent phase offset signals based on the previous, current, and subsequent samples, respectively. The receiver uses the previous phase offset signal to adjust clock frequency and clock phase of the current samples, thereby resulting in current adjusted samples. The receiver adjusts clock phase of the current adjusted samples based on any one of the previous, current, and subsequent phase offset signals. In some examples, receiver adjusts the clock phase of the current adjusted samples based on the subsequent phase offset signal.Type: ApplicationFiled: September 24, 2021Publication date: September 15, 2022Inventors: Shahab OVEIS GHARAN, James St. Leger HARLEY, Tung Trong NGUYEN
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Patent number: 11362700Abstract: An apparatus comprises a frequency accumulator to produce a frequency ramp, and a symbol modulator to receive symbols and to add to the frequency ramp frequency offsets representative of the symbols, to produce a modulated frequency ramp for a modulated chirp. The apparatus includes a spreading factor controller to control a roll-over rate of the modulated frequency ramp responsive to spreading factor and frequency bandwidth control signals, to control a spreading factor and a frequency bandwidth of the modulated chirp. The apparatus includes a center frequency controller to control a center frequency of the modulated frequency ramp responsive to a center frequency control signal. The apparatus includes a phase accumulator to accumulate frequency samples of the modulated frequency ramp to produce phase samples corresponding to the modulated chirp, and a vector rotator to rotate the phase samples based on an input vector to produce a modulated chirp.Type: GrantFiled: December 23, 2020Date of Patent: June 14, 2022Assignee: CISCO SYSTEMS CANADA CO.Inventors: Tung Trong Nguyen, Ha Hoang Nguyen
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Patent number: 11190277Abstract: Upon receiving a communications signal conveying symbols at a symbol period T, a receiver applies filter coefficients to a digital representation of the communications signal, thereby generating filtered signals characterized by a substantially raised cosine shape in the frequency domain with a roll-off factor ?, where components of the filtered signals correspond to angular frequencies ? = - ? ? ( 1 + ? ) T ? … - ? ? ( 1 - ? ) T , + ? ? ( 1 - ? ) T ? … + ? ? ( 1 + ? ) T . The receiver calculates first-order components from a first phase derivative of the components at a first differential distance, second-order components from a second phase derivative of the first-order components at a second differential distance, and composite second-order components from an average of the second-order components over multiple time intervals.Type: GrantFiled: May 28, 2021Date of Patent: November 30, 2021Assignee: CIENA CORPORATIONInventors: Tung Trong Nguyen, Timothy James Creasy, Shahab Oveis Gharan
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Publication number: 20210111750Abstract: An apparatus comprises a frequency accumulator to produce a frequency ramp, and a symbol modulator to receive symbols and to add to the frequency ramp frequency offsets representative of the symbols, to produce a modulated frequency ramp for a modulated chirp. The apparatus includes a spreading factor controller to control a roll-over rate of the modulated frequency ramp responsive to spreading factor and frequency bandwidth control signals, to control a spreading factor and a frequency bandwidth of the modulated chirp. The apparatus includes a center frequency controller to control a center frequency of the modulated frequency ramp responsive to a center frequency control signal. The apparatus includes a phase accumulator to accumulate frequency samples of the modulated frequency ramp to produce phase samples corresponding to the modulated chirp, and a vector rotator to rotate the phase samples based on an input vector to produce a modulated chirp.Type: ApplicationFiled: December 23, 2020Publication date: April 15, 2021Inventors: Tung Trong Nguyen, Ha Hoang Nguyen
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Patent number: 10938440Abstract: An apparatus comprises a frequency accumulator to produce a frequency ramp, and a symbol modulator to receive symbols and to add to the frequency ramp frequency offsets representative of the symbols, to produce a modulated frequency ramp for a modulated chirp. The apparatus includes a spreading factor controller to control a roll-over rate of the modulated frequency ramp responsive to spreading factor and frequency bandwidth control signals, to control a spreading factor and a frequency bandwidth of the modulated chirp. The apparatus includes a center frequency controller to control a center frequency of the modulated frequency ramp responsive to a center frequency control signal. The apparatus includes a phase accumulator to accumulate frequency samples of the modulated frequency ramp to produce phase samples corresponding to the modulated chirp, and a vector rotator to rotate the phase samples based on an input vector to produce a modulated chirp.Type: GrantFiled: April 5, 2019Date of Patent: March 2, 2021Assignee: Cisco Systems Canada Co.Inventors: Tung Trong Nguyen, Ha Hoang Nguyen
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Publication number: 20190356351Abstract: An apparatus comprises a frequency accumulator to produce a frequency ramp, and a symbol modulator to receive symbols and to add to the frequency ramp frequency offsets representative of the symbols, to produce a modulated frequency ramp for a modulated chirp. The apparatus includes a spreading factor controller to control a roll-over rate of the modulated frequency ramp responsive to spreading factor and frequency bandwidth control signals, to control a spreading factor and a frequency bandwidth of the modulated chirp. The apparatus includes a center frequency controller to control a center frequency of the modulated frequency ramp responsive to a center frequency control signal. The apparatus includes a phase accumulator to accumulate frequency samples of the modulated frequency ramp to produce phase samples corresponding to the modulated chirp, and a vector rotator to rotate the phase samples based on an input vector to produce a modulated chirp.Type: ApplicationFiled: April 5, 2019Publication date: November 21, 2019Inventors: Tung Trong Nguyen, Ha Hoang Nguyen
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Patent number: 10419137Abstract: In a digital communication system there is provided a method for OFDM channel estimation that jointly considers the effects of coarse timing error and multipath propagation. The method uses an iterative channel estimation technique, which considers the practical scenario of fractional timing error and non-sample space echo delays. The method does not require channel state information such as second-order statistic of the channel impulse responses or the noise power. Moreover, timing error can be conveniently obtained with the proposed technique. Simulation shows that, when comparing OFDM channel estimation techniques under DOCSIS 3.1 realistic channel conditions, the proposed algorithm significantly outperforms conventional methods.Type: GrantFiled: November 13, 2017Date of Patent: September 17, 2019Assignee: VECIMA NETWORKS INC.Inventors: Brian Michael Berscheid, Tung Trong Nguyen, Joseph Eric Salt, Ha Hoang Nguyen
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Publication number: 20180337740Abstract: In a digital communication system there is provided a method for OFDM channel estimation that jointly considers the effects of coarse timing error and multipath propagation. The method uses an iterative channel estimation technique, which considers the practical scenario of fractional timing error and non-sample space echo delays. The method does not require channel state information such as second-order statistic of the channel impulse responses or the noise power. Moreover, timing error can be conveniently obtained with the proposed technique. Simulation shows that, when comparing OFDM channel estimation techniques under DOCSIS 3.1 realistic channel conditions, the proposed algorithm significantly outperforms conventional methods.Type: ApplicationFiled: November 13, 2017Publication date: November 22, 2018Inventors: Brian Michael Berscheid, Tung Trong Nguyen, Joseph Eric Salt, Ha Hoang Nguyen
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Patent number: 9853751Abstract: In a digital communication system there is provided a method for OFDM channel estimation that jointly considers the effects of coarse timing error and multipath propagation. The method uses an iterative channel estimation technique, which considers the practical scenario of fractional timing error and non-sample space echo delays. The method does not require channel state information such as second-order statistic of the channel impulse responses or the noise power. Moreover, timing error can be conveniently obtained with the proposed technique. Simulation shows that, when comparing OFDM channel estimation techniques under DOCSIS 3.1 realistic channel conditions, the proposed algorithm significantly outperforms conventional methods.Type: GrantFiled: December 21, 2015Date of Patent: December 26, 2017Assignee: Vecima Networks Inc.Inventors: Brian Michael Berscheid, Tung Trong Nguyen, Joseph Eric Salt, Ha Hoang Nguyen
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Publication number: 20170180063Abstract: In a digital communication system there is provided a method for OFDM channel estimation that jointly considers the effects of coarse timing error and multipath propagation. The method uses an iterative channel estimation technique, which considers the practical scenario of fractional timing error and non-sample space echo delays. The method does not require channel state information such as second-order statistic of the channel impulse responses or the noise power. Moreover, timing error can be conveniently obtained with the proposed technique. Simulation shows that, when comparing OFDM channel estimation techniques under DOCSIS 3.1 realistic channel conditions, the proposed algorithm significantly outperforms conventional methods.Type: ApplicationFiled: December 21, 2015Publication date: June 22, 2017Inventors: Brian Michael Berscheid, Tung Trong Nguyen, Joseph Eric Salt, Ha Hoang Nguyen