Patents by Inventor Eric Salt
Eric Salt 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: 11463982Abstract: A method is provided for geo-location of a wireless target device. The method is able to generate complete statistical information about the target device in the form of a joint probability density function of the target's location. The method includes obtaining time of arrival measurements associated with reception, at a plurality of receiver devices at known or measured locations, of one or more wireless transmissions made by a target device at a location that is unknown. Based on the time of arrival measurements, the method includes computing a joint probability density function that is descriptive of a probability that the target device is within any specified region. The method then involves applying the joint probability density function to a particular specified region to compute the probability that the location of the target device is within the particular specified region.Type: GrantFiled: October 12, 2020Date of Patent: October 4, 2022Assignee: CISCO SYSTEMS CANADA CO.Inventors: Joseph Eric Salt, Ha Hoang Nguyen
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Publication number: 20220014410Abstract: In embodiments of the presently described subject matter, two efficient PAPR reduction methods for OFDM signals based upon the principle of tone reservation and building upon the clipping noise analysis presented in “Analysis of clipping noise and tonereservation algorithms for peak reduction in OFDM systems,” L. Wang and C. Tellambura, IEEE Trans. Veh. Technol., vol. 57, pp. 1675-1694, May 2008 are provided, each comprising two stages. The first stage is performed offline to prepare a set of cancelation signals based on the settings of the OFDM system. In particular, these cancellation signals are constructed to cancel signals at different levels of maximum instantaneous power that are above a predefined threshold. The second stage is performed online and in an iterative manner to reduce the peaks of OFDM symbols by using the cancellation signals constructed in the first stage.Type: ApplicationFiled: September 23, 2021Publication date: January 13, 2022Inventors: Quang NGUYEN, Ha H NGUYEN, Brian BERSCHEID, Eric SALT
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Patent number: 11140011Abstract: In embodiments of the presently described subject matter, two efficient PAPR reduction methods for OFDM signals based upon the principle of tone reservation and building upon the clipping noise analysis presented in “Analysis of clipping noise and tone reservation algorithms for peak reduction in OFDM systems,” L. Wang and C. Tellambura, IEEE Trans. Veh. Technol., vol. 57, pp. 1675-1694, May 2008 are provided, each comprising two stages. The first stage is performed offline to prepare a set of cancellation signals based on the settings of the OFDM system. In particular, these cancellation signals are constructed to cancel signals at different levels of maximum instantaneous power that are above a predefined threshold. The second stage is performed online and in an iterative manner to reduce the peaks of OFDM symbols by using the cancellation signals constructed in the first stage.Type: GrantFiled: February 18, 2020Date of Patent: October 5, 2021Assignee: Vecima Networks Inc.Inventors: Quang Nguyen, Ha H. Nguyen, Brian Berscheid, Eric Salt
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Publication number: 20210212015Abstract: A method is provided for geo-location of a wireless target device. The method is able to generate complete statistical information about the target device in the form of a joint probability density function of the target's location. The method includes obtaining time of arrival measurements associated with reception, at a plurality of receiver devices at known or measured locations, of one or more wireless transmissions made by a target device at a location that is unknown. Based on the time of arrival measurements, the method includes computing a joint probability density function that is descriptive of a probability that the target device is within any specified region. The method then involves applying the joint probability density function to a particular specified region to compute the probability that the location of the target device is within the particular specified region.Type: ApplicationFiled: October 12, 2020Publication date: July 8, 2021Inventors: Joseph Eric Salt, Ha Hoang Nguyen
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Publication number: 20200267040Abstract: In embodiments of the presently described subject matter, two efficient PAPR reduction methods for OFDM signals based upon the principle of tone reservation and building upon the clipping noise analysis presented in “Analysis of clipping noise and tonereservation algorithms for peak reduction in OFDM systems,” L. Wang and C. Tellambura, IEEE Trans. Veh. Technol., vol. 57, pp. 1675-1694, May 2008 are provided, each comprising two stages. The first stage is performed offline to prepare a set of cancellation signals based on the settings of the OFDM system. In particular, these cancellation signals are constructed to cancel signals at different levels of maximum instantaneous power that are above a predefined threshold. The second stage is performed online and in an iterative manner to reduce the peaks of OFDM symbols by using the cancellation signals constructed in the first stage.Type: ApplicationFiled: February 18, 2020Publication date: August 20, 2020Inventors: Quang Nguyen, Ha H. Nguyen, Brian Berscheid, Eric Salt
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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
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Patent number: 8755462Abstract: In a DOCSIS transmission network, it is necessary for an upstream receiver to estimate and correct for errors in the carrier frequency of the transmission based upon observations of a preamble sequence. This task is complicated by the fact that microreflections in the upstream channels cause intersymbol interference, which tends to bias the frequency estimation circuit. An economical, ISI-immune algorithm is provided for estimating the carrier frequency of upstream transmissions. The arrangement improves the reliability of the frequency estimates in the presence of ISI, thereby reducing the overhead and increasing the throughput of the upstream channels.Type: GrantFiled: September 8, 2011Date of Patent: June 17, 2014Assignee: Vecima Networks Inc.Inventors: Brian Berscheid, Eric Salt, Ha Nguyen
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Patent number: 8411733Abstract: In an RF signal transmission network such as the reverse channels of a coaxial cable network, there is provided at least one adaptive equalizer for pre- or post-filtering inter-symbol interference in the transmitted signals, the adaptive equalizer having a series of coefficients for which values are required. In order to improve the transmission efficiency the preamble used in these channels is shortened by coarsely estimating the channel using a short “unique word’ placed at the beginning of the equalizer training sequence. The coarse channel estimate is crudely inverted to produce a set of equalizer coefficients which partially equalize the channel. By initializing the adaptive equalizer with these approximate coefficients, it is possible to reduce the length of the training sequence needed for the equalizer to converge.Type: GrantFiled: June 15, 2010Date of Patent: April 2, 2013Assignee: Vecima Networks IncInventors: Brian Berscheid, Zohreh Andalibi, Eric Salt
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Publication number: 20120069916Abstract: In a DOCSIS transmission network, it is necessary for an upstream receiver to estimate and correct for errors in the carrier frequency of the transmission based upon observations of a preamble sequence. This task is complicated by the fact that microreflections in the upstream channels cause intersymbol interference, which tends to bias the frequency estimation circuit. An economical, ISI-immune algorithm is provided for estimating the carrier frequency of upstream transmissions. The arrangement improves the reliability of the frequency estimates in the presence of ISI, thereby reducing the overhead and increasing the throughput of the upstream channels.Type: ApplicationFiled: September 8, 2011Publication date: March 22, 2012Inventors: Brian Berscheid, Eric Salt, Ha Nguyen
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Publication number: 20100316111Abstract: In an RF signal transmission network such as the reverse channels of a coaxial cable network, there is provided at least one adaptive equalizer for pre- or post-filtering inter-symbol interference in the transmitted signals, the adaptive equalizer having a series of coefficients for which values are required. In order to improve the transmission efficiency the preamble used in these channels is shortened by coarsely estimating the channel using a short “unique word’ placed at the beginning of the equalizer training sequence. The coarse channel estimate is crudely inverted to produce a set of equalizer coefficients which partially equalize the channel. By initializing the adaptive equalizer with these approximate coefficients, it is possible to reduce the length of the training sequence needed for the equalizer to converge.Type: ApplicationFiled: June 15, 2010Publication date: December 16, 2010Inventors: Brian Berscheid, Zohreh Andalibi, Eric Salt
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Patent number: 6389085Abstract: Apparatus for and method of processing received signals for use with multiple antenna spatial diversity receivers used in a digital communications system. The receiver has received signal phase modulator apparatus for each diversity received signal. The phase modulator provides a two state phase perturbation of zero or pi radians, based on the carrier frequency, which is switched to modulate the phase of the received signal for a fifty percent duty cycle over a symbol period.Type: GrantFiled: January 14, 1998Date of Patent: May 14, 2002Assignee: Wavecom Electronics Inc.Inventor: J. Eric Salt
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Publication number: 20010022822Abstract: Apparatus for and method of processing received signals for use with multiple antenna spatial diversity receivers used in a digital communications system. The receiver has received signal phase modulator apparatus for each diversity received signal. The phase modulator provides a two state phase perturbation of zero or pi radians, based on the carrier frequency, which is switched to modulate the phase of the received signal for a fifty percent duty cycle over a symbol period.Type: ApplicationFiled: March 19, 2001Publication date: September 20, 2001Inventor: J. Eric Salt
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Patent number: 5615175Abstract: The present invention relates to a system and a method for determining the earing of an object located at a distance from a reference point. A plurality of sensors are mounted to a body to detect signals emanating from the object and to convert those signals into electrical signals. The electrical signals are then processed to determine the bearing of the object from the body. The system can include a float with the body suspended from said float immersed in a fluid medium. A method for processing the electrical signals and generating the bearing information is also described.Type: GrantFiled: September 19, 1995Date of Patent: March 25, 1997Assignee: The United States of America as represented by the Secretary of the NavyInventors: G. Clifford Carter, J. Eric Salt, Yun X. Yuan