Patents by Inventor Andrew Joo Kim
Andrew Joo Kim 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: 7725079Abstract: Signals propagating on an aggressor communication channel can cause detrimental interference in a victim communication channel. A signal processing circuit can generate an interference cancellation signal that, when applied to the victim communication channel, cancels the detrimental interference. The signal processing circuit can dynamically adjust or update two or more aspects of the interference cancellation signal, such as an amplitude or gain parameter and a phase or delay parameter. Via the dynamic adjustments, the signal processing circuit can adapt to changing conditions, thereby maintaining an acceptable level of interference cancellation in a fluctuating operating environment. A control circuit that implements the parametric adjustments can have at least two modes of operation, one for adjusting the amplitude parameter and one for adjusting the phase parameter. The modes can be selectable or can be intermittently available, for example.Type: GrantFiled: June 9, 2006Date of Patent: May 25, 2010Assignee: Quellan, Inc.Inventors: Andrew Joo Kim, Edward Gebara, Bruce C. Schmukler, Mark W. Dickmann, Michael F. Farrell, Michael G. Vrazel, David Anthony Stelliga, Joy Laskar, Charles E. Summers
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Publication number: 20100040180Abstract: A Signal Conditioning Filter (SCF) and a Signal Integrity Unit (SIU) address the coupled problem of equalization and noise filtering in order to improve signal fidelity for decoding. Specifically, a received signal can be filtered in a manner to optimize the signal fidelity even in the presence of both significant (large magnitudes of) ISI and noise. The present invention can provide an adaptive method that continuously monitors a signal fidelity measure. Monitoring the fidelity of a multilevel signal can be performed by external means such as by the SIU. A received signal y(t) can be “conditioned” by application of a filter with an electronically adjustable impulse response g(t). A resulting output z(t) can then be interrogated to characterize the quality of the conditioned signal. This fidelity measure q(t) can be used to adjust the filter response to maximize the fidelity measure of the conditioned signal.Type: ApplicationFiled: August 11, 2009Publication date: February 18, 2010Inventors: Andrew Joo Kim, Vincent Mark Hietala, Sanjay Bajekal
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Publication number: 20100039923Abstract: Signals propagating in one communication channel can generate crosstalk interference in another communication channel. A crosstalk cancellation device can process the signals causing the crosstalk interference and generate a crosstalk cancellation signal that can compensate for the crosstalk when applied to the channel receiving crosstalk interference. The crosstalk cancellation device can include a model of the crosstalk effect that generates a signal emulating the actual crosstalk both in form an in timing. The crosstalk cancellation device can include a controller that monitors crosstalk-compensated communication signals and adjusts the model to enhance crosstalk cancellation performance. The crosstalk cancellation device can have a mode of self configuration or calibration in which defined test signals can be transmitted on the crosstalk-generating channel and the crosstalk-receiving channel.Type: ApplicationFiled: October 19, 2009Publication date: February 18, 2010Applicant: Quellan, Inc.Inventors: Andrew Joo Kim, Michael G. Vrazel, Sanjay Bajekal, Charles Summers
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Publication number: 20100027709Abstract: A slicer can receive a communication signal having a level or amplitude that is between two discrete levels of a multilevel digital communication scheme. The slicer can compare the communication signal to a plurality of references such that multiple comparisons proceed essentially in parallel. A summation node can add the results of the comparisons to provide an output signal set to one of the discrete levels. The slicer can process the communication signal and provide the output signal on a symbol-by-symbol basis. A decision feedback equalizer (“DFE”) can comprise the slicer. A feedback circuit of the DFE can delay and scale the output signal and apply the delayed and scaled signal to the communication signal to reduce intersymbol interference (“ISI”).Type: ApplicationFiled: October 14, 2009Publication date: February 4, 2010Applicant: Quellan, Inc.Inventors: Andrew Joo Kim, Cattalen Pelard, Edward Gebara
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Patent number: 7626916Abstract: Signals propagating in one communication channel can generate crosstalk interference in another communication channel. A crosstalk cancellation device can process the signals causing the crosstalk interference and generate a crosstalk cancellation signal that can compensate for the crosstalk when applied to the channel receiving crosstalk interference. The crosstalk cancellation device can include a model of the crosstalk effect that generates a signal emulating the actual crosstalk both in form an in timing. The crosstalk cancellation device can include a controller that monitors crosstalk-compensated communication signals and adjusts the model to enhance crosstalk cancellation performance. The crosstalk cancellation device can have a mode of self configuration or calibration in which defined test signals can be transmitted on the crosstalk-generating channel and the crosstalk-receiving channel.Type: GrantFiled: January 19, 2006Date of Patent: December 1, 2009Assignee: Quellan, Inc.Inventors: Andrew Joo Kim, Michael G. Vrazel, Sanjay Bajekal, Charles Summers
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Patent number: 7616700Abstract: A slicer can receive a communication signal having a level or amplitude that is between two discrete levels of a multilevel digital communication scheme. The slicer can compare the communication signal to a plurality of references such that multiple comparisons proceed essentially in parallel. A summation node can add the results of the comparisons to provide an output signal set to one of the discrete levels. The slicer can process the communication signal and provide the output signal on a symbol-by-symbol basis. A decision feedback equalizer (“DFE”) can comprise the slicer. A feedback circuit of the DFE can delay and scale the output signal and apply the delayed and scaled signal to the communication signal to reduce intersymbol interference (“ISI”).Type: GrantFiled: December 22, 2004Date of Patent: November 10, 2009Assignee: Quellan, Inc.Inventors: Andrew Joo Kim, Cattalen Pelard, Edward Gebara
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Patent number: 7602860Abstract: A multilevel optical receiver can comprise a plurality of comparators that generally correspond with the number of levels in a multilevel data stream. Each comparator can be individually controlled and fed a decision threshold in order to decode a multilevel signal. The multilevel optical receiver can generate a statistical characterization of the received symbols in the form of a marginal cumulative distribution function (CDF) or probability density function (pdf). This characterization can be used to produce a set of ?-support estimates from which conditional pdfs are derived for each of the transmission symbols. These conditional pdfs may then be used to determine decision thresholds for decoding the received signal. The conditional pdfs may further be used to continuously estimate the fidelity or error rate of the received signal without the transmission of a testing sequence. The ?-supports may further be used to automatically control the gain on the receiver.Type: GrantFiled: December 4, 2006Date of Patent: October 13, 2009Assignee: Quellan, Inc.Inventors: Vincent Mark Hietala, Andrew Joo Kim
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Patent number: 7573966Abstract: A Signal Conditioning Filter (SCF) and a Signal Integrity Unit (SIU) address the coupled problem of equalization and noise filtering in order to improve signal fidelity for decoding. Specifically, a received signal can be filtered in a manner to optimize the signal fidelity even in the presence of both significant (large magnitudes of) ISI and noise. The present invention can provide an adaptive method that continuously monitors a signal fidelity measure. Monitoring the fidelity of a multilevel signal can be performed by external means such as by the SIU. A received signal y(t) can be “conditioned” by application of a filter with an electronically adjustable impulse response g(t). A resulting output z(t) can then be interrogated to characterize the quality of the conditioned signal. This fidelity measure q(t) can be used to adjust the filter response to maximize the fidelity measure of the conditioned signal.Type: GrantFiled: February 21, 2006Date of Patent: August 11, 2009Assignee: Quellan, Inc.Inventors: Andrew Joo Kim, Vincent Mark Hietala, Sanjay Bajekal
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Publication number: 20090170438Abstract: Signals propagating on an aggressor communication channel can cause interference in a victim communication channel. A sensor coupled to the aggressor channel can obtain a sample of the aggressor signal. The sensor can be integrated with or embedded in a system, such as a flex circuit or a circuit board, that comprises the aggressor channel. The sensor can comprise a dedicated conductor or circuit trace that is near an aggressor conductor, a victim conductor, or an EM field associated with the interference. An interference compensation circuit can receive the sample from the sensor. The interference compensation circuit can have at least two operational modes of operation. In the first mode, the circuit can actively generate or output a compensation signal that cancels, corrects, or suppresses the interference. The second mode can be a standby, idle, power-saving, passive, or sleep mode.Type: ApplicationFiled: March 2, 2009Publication date: July 2, 2009Inventors: Edward Gebara, Andrew Joo Kim, Joy Laskar, Anthony Stelliga, Emmanouil M. Tentzeris
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Patent number: 7522883Abstract: Signals propagating on an aggressor communication channel can cause interference in a victim communication channel. A sensor coupled to the aggressor channel can obtain a sample of the aggressor signal. The sensor can be integrated with or embedded in a system, such as a flex circuit or a circuit board, that comprises the aggressor channel. The sensor can comprise a dedicated conductor or circuit trace that is near an aggressor conductor, a victim conductor, or an EM field associated with the interference. An interference compensation circuit can receive the sample from the sensor. The interference compensation circuit can have at least two operational modes of operation. In the first mode, the circuit can actively generate or output a compensation signal that cancels, corrects, or suppresses the interference. The second mode can be a standby, idle, power-saving, passive, or sleep mode.Type: GrantFiled: December 14, 2005Date of Patent: April 21, 2009Assignee: Quellan, Inc.Inventors: Edward Gebara, Andrew Joo Kim, Joy Laskar, Anthony Stelliga, Emmanouil M. Tentzeris
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Publication number: 20080146183Abstract: A wireless communication system can comprise two or more antennas that interfere with one another via free space coupling, surface wave crosstalk, dielectric leakage, or other interference effect. The interference effect can produce an interference signal on one of the antennas. A cancellation device can suppress antenna interference by generating an estimate of the interference signal and subtracting the estimate from the interference signal. The cancellation device can generate the estimate based on sampling signals on an antenna that generates the interference or on an antenna that receives the interference. The cancellation device can comprise a model of the crosstalk effect. Transmitting test signals on the communication system can define or refine the model.Type: ApplicationFiled: February 8, 2008Publication date: June 19, 2008Applicant: Quellan, Inc.Inventors: Edward Gebara, Joy Laskar, Emmanouil M. Tentzeris, Andrew Joo Kim
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Patent number: 7366244Abstract: A wireless communication system can comprise two or more antennas that interfere with one another via free space coupling, surface wave crosstalk, dielectric leakage, or other interference effect. The interference effect can produce an interference signal on one of the antennas. A cancellation device can suppress antenna interference by generating an estimate of the interference signal and subtracting the estimate from the interference signal. The cancellation device can generate the estimate based on sampling signals on an antenna that generates the interference or on an antenna that receives the interference. The cancellation device can comprise a model of the crosstalk effect. Transmitting test signals on the communication system can define or refine the model.Type: GrantFiled: August 30, 2006Date of Patent: April 29, 2008Assignee: Quellan, Inc.Inventors: Edward Gebara, Joy Laskar, Emmanouil M. Tentzeris, Andrew Joo Kim
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Publication number: 20070253495Abstract: A communications channel may radiate energy undesirably, for example in the form of electromagnetic radiation, when a communication signal transmits over the communications channel. Processing the signal before and after transmission on the communications channel can reduce the level of radiated energy. Signal processing in advance of transmission over the communications channel can transform the communication signal into a waveform that has a reduced propensity to emit radiated energy during transmission over the communications channel. Exemplary signal transformations can involve applying either frequency-selective or broadband attenuation to the communication signal. Following transmission of the waveform over the communications channel, the original communication signal can be restored via reversing the signal transformation. The reverse transformation can comprise applying frequency-selective gain or broadband gain to the transmitted waveform.Type: ApplicationFiled: April 26, 2007Publication date: November 1, 2007Inventor: Andrew Joo Kim
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Patent number: 7215721Abstract: A multilevel optical receiver can comprise a plurality of comparators that generally correspond with the number of levels in a multilevel data stream. Each comparator can be individually controlled and fed a decision threshold in order to decode a multilevel signal. The multilevel optical receiver can generate a statistical characterization of the received symbols in the form of a marginal cumulative distribution function (CDF) or probability density function (pdf). This characterization can be used to produce a set of ?-support estimates from which conditional pdfs are derived for each of the transmission symbols. These conditional pdfs may then be used to determine decision thresholds for decoding the received signal. The conditional pdfs may further be used to continuously estimate the fidelity or error rate of the received signal without the transmission of a testing sequence. The ?-supports may further be used to automatically control the gain on the receiver.Type: GrantFiled: March 28, 2002Date of Patent: May 8, 2007Assignee: Quellan, Inc.Inventors: Vincent Mark Hietala, Andrew Joo Kim
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Patent number: 7212580Abstract: Clock recovery of a multi-level (ML) signal can be performed in a two-step process. First, the transitions within the ML signal can be detected by a novel transition detector (TD). And second, the output of the TD circuit can comprise a pseudo-non-return-to-zero (pNRZ) signal that can drive a conventional OOK clock recovery (CR) IC. The TD circuit can convert the edges of the ML signal into the pseudo-NRZ (pNRZ) signal. The TD circuit can capture as many transitions as possible to allow the conventional NRZ clock recovery (CR) chip to optimally perform. The TD circuit can differentiate the ML signal in order to detect the ML signal's transitions.Type: GrantFiled: February 12, 2003Date of Patent: May 1, 2007Assignee: Quellan, Inc.Inventors: Vincent Mark Hietala, Andrew Joo Kim
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Publication number: 20060291598Abstract: A wireless communication system can comprise two or more antennas that interfere with one another via free space coupling, surface wave crosstalk, dielectric leakage, or other interference effect. The interference effect can produce an interference signal on one of the antennas. A cancellation device can suppress antenna interference by generating an estimate of the interference signal and subtracting the estimate from the interference signal. The cancellation device can generate the estimate based on sampling signals on an antenna that generates the interference or on an antenna that receives the interference. The cancellation device can comprise a model of the crosstalk effect. Transmitting test signals on the communication system can define or refine the model.Type: ApplicationFiled: August 30, 2006Publication date: December 28, 2006Applicant: Quellan, Inc.Inventors: Edward Gebara, Joy Laskar, Emmanouil Tentzeris, Andrew Joo Kim
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Patent number: 7123676Abstract: A wireless communication system can comprise two or more antennas that interfere with one another via free space coupling, surface wave crosstalk, dielectric leakage, or other interference effect. The interference effect can produce an interference signal on one of the antennas. A cancellation device can suppress antenna interference by generating an estimate of the interference signal and subtracting the estimate from the interference signal. The cancellation device can generate the estimate based on sampling signals on an antenna that generates the interference or on an antenna that receives the interference. The cancellation device can comprise a model of the crosstalk effect. Transmitting test signals on the communication system can define or refine the model.Type: GrantFiled: November 17, 2004Date of Patent: October 17, 2006Assignee: Quellan, Inc.Inventors: Edward Gebara, Joy Laskar, Emmanouil M. Tentzeris, Andrew Joo Kim
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Patent number: 7050388Abstract: Signals propagating in one communication channel can generate crosstalk interference in another communication channel. A crosstalk cancellation device can process the signals causing the crosstalk interference and generate a crosstalk cancellation signal that can compensate for the crosstalk when applied to the channel receiving crosstalk interference. The crosstalk cancellation device can include a model of the crosstalk effect that generates a signal emulating the actual crosstalk both in form an in timing. The crosstalk cancellation device can include a controller that monitors crosstalk-compensated communication signals and adjusts the model to enhance crosstalk cancellation performance. The crosstalk cancellation device can have a mode of self configuration or calibration in which defined test signals can be transmitted on the crosstalk-generating channel and the crosstalk-receiving channel.Type: GrantFiled: August 5, 2004Date of Patent: May 23, 2006Assignee: Quellan, Inc.Inventors: Andrew Joo Kim, Michael G. Vrazel, Sanjay Bajekal, Charles Summers
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Patent number: 7035361Abstract: A Signal Conditioning Filter (SCF) and a Signal Integrity Unit (SIU) address the coupled problem of equalization and noise filtering in order to improve signal fidelity for decoding. Specifically, a received signal can be filtered in a manner to optimize the signal fidelity even in the presence of both significant (large magnitudes of) ISI and noise. The present invention can provide an adaptive method that continuously monitors a signal fidelity measure. Monitoring the fidelity of a multilevel signal can be performed by external means such as by the SIU. A received signal y(t) can be “conditioned” by application of a filter with an electronically adjustable impulse response g(t). A resulting output z(t) can then be interrogated to characterize the quality of the conditioned signal. This fidelity measure q(t) can be used to adjust the filter response to maximize the fidelity measure of the conditioned signal.Type: GrantFiled: July 15, 2003Date of Patent: April 25, 2006Assignee: Quellan, Inc.Inventors: Andrew Joo Kim, Vincent Mark Hietala, Sanjay Bajekal
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Publication number: 20050180520Abstract: A slicer can receive a communication signal having a level or amplitude that is between two discrete levels of a multilevel digital communication scheme. The slicer can compare the communication signal to a plurality of references such that multiple comparisons proceed essentially in parallel. A summation node can add the results of the comparisons to provide an output signal set to one of the discrete levels. The slicer can process the communication signal and provide the output signal on a symbol-by-symbol basis. A decision feedback equalizer (“DFE”) can comprise the slicer. A feedback circuit of the DFE can delay and scale the output signal and apply the delayed and scaled signal to the communication signal to reduce intersymbol interference (“ISI”).Type: ApplicationFiled: December 22, 2004Publication date: August 18, 2005Applicant: Quellan, Inc.Inventors: Andrew Joo Kim, Cattalen Pelard, Edward Gebara