Patents by Inventor Ioannis Spyropoulos
Ioannis Spyropoulos 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).
-
Publication number: 20230412276Abstract: A calibration system comprises control circuitry and waveform capture circuitry. The control circuitry selects a first calibration waveform for input to a digital predistortion circuit of a transmitter. The capture circuitry captures a first waveform output by the transmitter in response to the first calibration waveform. The control circuitry compares the first calibration waveform to the captured first waveform. The control circuitry selects a first one of a plurality of mapping circuit configurations based on the result of the comparison, wherein the mapping circuit is configured to map outputs of a plurality of delay circuits among inputs of a plurality of filter taps. The control circuitry stores the one of the mapping circuit configurations in nonvolatile memory associated with the transmitter.Type: ApplicationFiled: July 25, 2023Publication date: December 21, 2023Applicant: Maxlinear, Inc.Inventors: Ioannis Spyropoulos, Anand Anandakumar
-
Publication number: 20230327922Abstract: According to an aspect of an embodiment, a decision feedback equalizer (DFE) may be configured for noise suppression slicing. The DFE may be configured to receive, from a feedforward equalizer, an output signal having a received (Rx) symbol. The DFE may be configured to initialize noise suppression slicer (NSS) parameters including one or more initial NSS coefficients and one or more initial slicer deferred decision (SDD) threshold offsets. The DFE may be configured to determine one or more updated NSS coefficients. The DFE may be configured to determine one or more updated SDD threshold offsets. The DFE may be configured to update the NSS parameters of a processing register based on the one or more updated NSS coefficients and the one or more updated SDD threshold offsets.Type: ApplicationFiled: April 12, 2023Publication date: October 12, 2023Inventors: Sridhar Ramesh, Ioannis Spyropoulos
-
Patent number: 11711149Abstract: A calibration system comprises control circuitry and waveform capture circuitry. The control circuitry selects a first calibration waveform for input to a digital predistortion circuit of a transmitter. The capture circuitry captures a first waveform output by the transmitter in response to the first calibration waveform. The control circuitry compares the first calibration waveform to the captured first waveform. The control circuitry selects a first one of a plurality of mapping circuit configurations based on the result of the comparison, wherein the mapping circuit is configured to map outputs of a plurality of delay circuits among inputs of a plurality of filter taps. The control circuitry stores the one of the mapping circuit configurations in nonvolatile memory associated with the transmitter.Type: GrantFiled: April 9, 2019Date of Patent: July 25, 2023Assignee: MaxLinear, Inc.Inventors: Ioannis Spyropoulos, Anand Anandakumar
-
Patent number: 10826616Abstract: A system comprises a digital predistortion circuit comprising: a first quantity of delay circuits configured to delay a signal to be predistorted; a second quantity of filter tap circuits, wherein the second quantity is smaller than the first quantity; and a delay-to-filter-taps mapping circuit that is operable to map each output of a first subset of the delay circuits to a corresponding input of the filter tap circuits. The system may comprise circuitry operable to select which of the first quantity of delay circuits is in the first subset. The selection of which of the first quantity of delay circuits is in the first subset may be based on a temperature measurement. The digital predistortion circuit may comprise cross-term generation circuitry operable to generate cross-term signals corresponding to the cross products of multiple, differently-delayed versions of a signal input to the digital predistortion circuit.Type: GrantFiled: April 5, 2019Date of Patent: November 3, 2020Assignee: MaxLinear, Inc.Inventors: Ioannis Spyropoulos, Anand Anandakumar
-
Patent number: 10764078Abstract: A transmitter is configured to generate a DOCSIS signal for transmission onto a frequency-selective coaxial cable. The transmitter comprises a first reverse tilt filter circuit, a digital predistortion circuit, a forward tilt filter, a wideband equalizer, a second reverse tilt filter, and a power amplifier. The responses of the tilt filters may be set based on the frequency response of the frequency-selective coaxial cable to which the transmitter is intended to be coupled. The predistortion circuit may compensate for distortion introduced by circuitry of the transmitter. The equalizer circuit may be operable to compensate for undesired linear response of other circuitry of the transmitter.Type: GrantFiled: March 18, 2019Date of Patent: September 1, 2020Assignee: MaxLinear, Inc.Inventors: Mario Milicevic, Ioannis Spyropoulos
-
Publication number: 20190312649Abstract: A system comprises a digital predistortion circuit comprising: a first quantity of delay circuits configured to delay a signal to be predistorted; a second quantity of filter tap circuits, wherein the second quantity is smaller than the first quantity; and a delay-to-filter-taps mapping circuit that is operable to map each output of a first subset of the delay circuits to a corresponding input of the filter tap circuits. The system may comprise circuitry operable to select which of the first quantity of delay circuits is in the first subset. The selection of which of the first quantity of delay circuits is in the first subset may be based on a temperature measurement. The digital predistortion circuit may comprise cross-term generation circuitry operable to generate cross-term signals corresponding to the cross products of multiple, differently-delayed versions of a signal input to the digital predistortion circuit.Type: ApplicationFiled: April 5, 2019Publication date: October 10, 2019Inventors: Ioannis Spyropoulos, Anand Anandakumar
-
Publication number: 20190312650Abstract: A calibration system comprises control circuitry and waveform capture circuitry. The control circuitry selects a first calibration waveform for input to a digital predistortion circuit of a transmitter. The capture circuitry captures a first waveform output by the transmitter in response to the first calibration waveform. The control circuitry compares the first calibration waveform to the captured first waveform. The control circuitry selects a first one of a plurality of mapping circuit configurations based on the result of the comparison, wherein the mapping circuit is configured to map outputs of a plurality of delay circuits among inputs of a plurality of filter taps. The control circuitry stores the one of the mapping circuit configurations in nonvolatile memory associated with the transmitter.Type: ApplicationFiled: April 9, 2019Publication date: October 10, 2019Inventors: Ioannis Spyropoulos, Anand Anandakumar
-
Publication number: 20190296929Abstract: A transmitter is configured to generate a DOCSIS signal for transmission onto a frequency-selective coaxial cable. The transmitter comprises a first reverse tilt filter circuit, a digital predistortion circuit, a forward tilt filter, a wideband equalizer, a second reverse tilt filter, and a power amplifier. The responses of the tilt filters may be set based on the frequency response of the frequency-selective coaxial cable to which the transmitter is intended to be coupled. The predistortion circuit may compensate for distortion introduced by circuitry of the transmitter. The equalizer circuit may be operable to compensate for undesired linear response of other circuitry of the transmitter.Type: ApplicationFiled: March 18, 2019Publication date: September 26, 2019Inventors: Mario Milicevic, Ioannis Spyropoulos
-
Patent number: 10404497Abstract: An electronic receiver may generate a differential detection sequence based on a received symbol sequence and based on a m-symbol delayed version of the received symbol sequence, where in is an integer greater than 1. The particular differential detection sequence may be a result of an element-by-element multiplication of the particular received symbol sequence and the conjugate of an in-symbol delayed version of the particular received symbol sequence. The receiver may calculate differential decision metrics based on the differential detection sequence and based on a set of differential symbol sequences generated from the set of possible transmitted symbol sequences. The receiver may generate a decision as to which of a set of possible transmitted symbol sequences resulted in the received symbol sequence, where the decision is based on the differential decision metrics and the set of possible transmitted symbols sequences.Type: GrantFiled: September 20, 2018Date of Patent: September 3, 2019Assignee: Maxlinear, Inc.Inventors: Ioannis Spyropoulos, Anand Anandakumar
-
Patent number: 10389449Abstract: Aspects of a method and system for feedback during optical communications are provided. In one embodiment, a system for optical communications comprises a predistortion module, a feedback subsystem, a transmit optical subsystem, and an external modulator. The predistortion module is operable to receive an input digital signal and modify the input digital signal to produce a digital predistorted signal. The transmit optical subsystem is operable to generate an optical signal from the digital predistorted signal. The modification of the input digital signal is dynamically controlled by the feedback subsystem according to one or more characteristics of the optical signal as determined by the feedback subsystem. The amplitude of the external modulator output is also dynamically controlled by the feedback subsystem.Type: GrantFiled: September 19, 2018Date of Patent: August 20, 2019Assignee: Maxlinear, Inc.Inventors: Curtis Ling, Anand Anandakumar, Ioannis Spyropoulos
-
Publication number: 20190020513Abstract: An electronic receiver may generate a differential detection sequence based on a received symbol sequence and based on a m-symbol delayed version of the received symbol sequence, where in is an integer greater than 1. The particular differential detection sequence may be a result of an element-by-element multiplication of the particular received symbol sequence and the conjugate of an in-symbol delayed version of the particular received symbol sequence. The receiver may calculate differential decision metrics based on the differential detection sequence and based on a set of differential symbol sequences generated from the set of possible transmitted symbol sequences. The receiver may generate a decision as to which of a set of possible transmitted symbol sequences resulted in the received symbol sequence, where the decision is based on the differential decision metrics and the set of possible transmitted symbols sequences.Type: ApplicationFiled: September 20, 2018Publication date: January 17, 2019Inventors: Ioannis Spyropoulos, Anand Anandakumar
-
Publication number: 20190013867Abstract: Aspects of a method and system for feedback during optical communications are provided. In one embodiment, a system for optical communications comprises a predistortion module, a feedback subsystem, a transmit optical subsystem, and an external modulator. The predistortion module is operable to receive an input digital signal and modify the input digital signal to produce a digital predistorted signal. The transmit optical subsystem is operable to generate an optical signal from the digital predistorted signal. The modification of the input digital signal is dynamically controlled by the feedback subsystem according to one or more characteristics of the optical signal as determined by the feedback subsystem. The amplitude of the external modulator output is also dynamically controlled by the feedback subsystem.Type: ApplicationFiled: September 19, 2018Publication date: January 10, 2019Inventors: Curtis Ling, Anand Anandakumar, Ioannis Spyropoulos
-
Patent number: 10116469Abstract: An electronic receiver may generate a differential detection sequence based on a received symbol sequence and based on a m-symbol delayed version of the received symbol sequence, where m is an integer greater than 1. The particular differential detection sequence may be a result of an element-by-element multiplication of the particular received symbol sequence and the conjugate of an m-symbol delayed version of the particular received symbol sequence. The receiver may calculate differential decision metrics based on the differential detection sequence and based on a set of differential symbol sequences generated from the set of possible transmitted symbol sequences. The receiver may generate a decision as to which of a set of possible transmitted symbol sequences resulted in the received symbol sequence, where the decision is based on the differential decision metrics and the set of possible transmitted symbols sequences.Type: GrantFiled: December 13, 2017Date of Patent: October 30, 2018Assignee: Maxlinear, Inc.Inventors: Ioannis Spyropoulos, Anand Anandakumar
-
Patent number: 10116390Abstract: Aspects of a method and system for feedback during optical communications are provided. In one embodiment, a system for optical communications comprises a predistortion module, a feedback subsystem, a transmit optical subsystem, and an external modulator. The predistortion module is operable to receive an input digital signal and modify the input digital signal to produce a digital predistorted signal. The transmit optical subsystem is operable to generate an optical signal from the digital predistorted signal. The modification of the input digital signal is dynamically controlled by the feedback subsystem according to one or more characteristics of the optical signal as determined by the feedback subsystem. The amplitude of the external modulator output is also dynamically controlled by the feedback subsystem.Type: GrantFiled: June 17, 2016Date of Patent: October 30, 2018Assignee: Maxlinear, Inc.Inventors: Curtis Ling, Anand Anandakumar, Ioannis Spyropoulos
-
Publication number: 20180294879Abstract: Aspects of a method and system for feedback during optical communications are provided. In one embodiment, a system for optical communications comprises a digital-to-analog converter (DAC), a driver, and a transmit optical subsystem. The DAC is operable to receive a digital code of a plurality of digital codes and output an analog current signal having an analog current level of a plurality of analog current levels. The driver is operable to condition the analog current signal output from the digital-to-analog converter. The transmit optical subsystem is operable to generate an optical signal from the conditioned analog current signal. A digital modification of an input digital signal is dynamically controlled by a feedback path according to one or more characteristics of the optical signal. The one or more characteristics comprise a nonlinearity that may be temperature dependent.Type: ApplicationFiled: June 14, 2018Publication date: October 11, 2018Inventors: Anand Anandakumar, Ioannis Spyropoulos, Curtis Ling
-
Publication number: 20180234740Abstract: Methods and systems are provided for using priori knowledge of noise in controlling signal receivers. In a signal receiver, one or more adjustments, relating to generating output signals via the signal receiver, may be determined, with the adjustments directed to one or more particular components of the output signals. When applying the adjustments is determined to cause undesired effects on one or more other components of the output signals, with these other components being intended to remain unchanged when the adjustments are applied, operations of the signal receiver may be controlled based on the undesired effects, with the controlling including mitigating at least some of the effects on the one or more other components of the signals when the one or more adjustments are applied. The adjustments may include frequency re-assignment. The undesired effects may include one or more of amplitude glitches, phase glitches, bit or packet errors, etc.Type: ApplicationFiled: February 5, 2018Publication date: August 16, 2018Inventors: Anand Anandakumar, Ioannis Spyropoulos, Meetul Parikh
-
Patent number: 10050710Abstract: Aspects of a method and system for feedback during optical communications are provided. In one embodiment, a system for optical communications comprises a digital-to-analog converter (DAC), a driver, and a transmit optical subsystem. The DAC is operable to receive a digital code of a plurality of digital codes and output an analog current signal having an analog current level of a plurality of analog current levels. The driver is operable to condition the analog current signal output from the digital-to-analog converter. The transmit optical subsystem is operable to generate an optical signal from the conditioned analog current signal. A digital modification of an input digital signal is dynamically controlled by a feedback path according to one or more characteristics of the optical signal. The one or more characteristics comprise a nonlinearity that may be temperature dependent.Type: GrantFiled: May 25, 2016Date of Patent: August 14, 2018Assignee: Maxlinear, Inc.Inventors: Anand Anandakumar, Ioannis Spyropoulos, Curtis Ling
-
Publication number: 20180115441Abstract: An electronic receiver may generate a differential detection sequence based on a received symbol sequence and based on a m-symbol delayed version of the received symbol sequence, where in is an integer greater than 1. The particular differential detection sequence may be a result of an element-by-element multiplication of the particular received symbol sequence and the conjugate of an in-symbol delayed version of the particular received symbol sequence. The receiver may calculate differential decision metrics based on the differential detection sequence and based on a set of differential symbol sequences generated from the set of possible transmitted symbol sequences. The receiver may generate a decision as to which of a set of possible transmitted symbol sequences resulted in the received symbol sequence, where the decision is based on the differential decision metrics and the set of possible transmitted symbols sequences.Type: ApplicationFiled: December 13, 2017Publication date: April 26, 2018Inventors: Ioannis Spyropoulos, Anand Anandakumar
-
Patent number: 9888294Abstract: A signal receiver may be configured to determine when signal generation adjustments directed to particular components of signals received by the signal receiver, cause performance changes relating to effects of the signal generation adjustments on other components of the received signals. Operations of the signal receiver may then be controlled based on the performance changes, to mitigate at least some of the effects on the one or more other components of the signals. The performance changes may comprise amplitude glitches, phase glitches, and/or bit or packet errors. The signal generation adjustments may comprise channel-to-frequency re-assignment. Controlling operations of the signal receiver may comprise adjusting such parameters as amplification gain and/or tracking loop bandwidth, and/or determining whether (or not) to ignore bit/packet errors.Type: GrantFiled: February 6, 2015Date of Patent: February 6, 2018Assignee: MaxLinear, Inc.Inventors: Anand Anandakumar, Ioannis Spyropoulos, Meetul Parikh
-
Patent number: 9876658Abstract: An electronic receiver may generate a differential detection sequence based on a received symbol sequence and based on a m-symbol delayed version of the received symbol sequence, where m is an integer greater than 1. The particular differential detection sequence may be a result of an element-by-element multiplication of the particular received symbol sequence and the conjugate of an m-symbol delayed version of the particular received symbol sequence. The receiver may calculate differential decision metrics based on the differential detection sequence and based on a set of differential symbol sequences generated from the set of possible transmitted symbol sequences. The receiver may generate a decision as to which of a set of possible transmitted symbol sequences resulted in the received symbol sequence, where the decision is based on the differential decision metrics and the set of possible transmitted symbols sequences.Type: GrantFiled: December 28, 2016Date of Patent: January 23, 2018Assignee: Maxlinear, Inc.Inventors: Ioannis Spyropoulos, Anand Anandakumar