Christopher A Hansen

US Patent:

6542477, Apr 1, 2003

Filed:

Mar 31, 1999

Appl. No.:

09/281903

Inventors:

Debajyoti Pal - Fremont CA
Sujai Chari - Redwood City CA
Christopher Hansen - Sunnyvale CA
Chung-Li Lu - Sunnyvale CA

Assignee:

Virata Corporation - Santa Clara CA

International Classification:

H04B 320

US Classification:

370286, 370288

Abstract:

The present invention, generally speaking, provides a digitally-tunable, echo-cancelling analog front end (AFE) for wireline digital communications. The analog front end is especially useful in a High-bit-rate Digital Subscriber Line (HDSL) or HDSL environment. An analog echo simulation path is provided capable of simulating echo from a wide variety of echo paths. Digitally controlled attenuators are provided in the transmission path and in the analog echo simulation path. Also provided is a digital-tunable equalizer stage. The equalizer stage is tuned to match the characteristics of the receive path. The same arrangement may be adapted for various DSL technologies, i. e. , xDSL. There results an analog front end that is well-adapted to high-speed wireline communications.

US Patent:

6707557, Mar 16, 2004

Filed:

Jan 2, 2001

Appl. No.:

09/753431

Inventors:

Richard D. Ball - Austin TX
Mark S. Bishop - Austin TX
Marc C. Digby - Austin TX
Christopher P. Hansen - Indianapolis IN
Philip E. Cannata - Austin TX

Assignee:

Eastman Kodak Company - Rochester NY

International Classification:

G01N 2186

US Classification:

356444

Abstract:

One aspect of the present invention is a system for estimating sensor and illumination non-uniformities. The system comprises a first light source, and a first sensor operable to capture light reflected from a first side of film illuminated by the light source while the film has a developer chemical applied thereto and processing circuitry coupled to the first sensor. The processing circuitry is operable to capture a first plurality of readings from the sensor responsive to light reflected from an unexposed region of film to determine a first set of non-uniformity data and adjust image data obtained from the film in response to the first set of non-uniformity data. In a further embodiment, the processing circuitry is further operable to dim the first light source for at least a portion of the time that the sensor is being used to sense the unexposed region of the film. The processing circuitry may also capture a second plurality of readings from the sensor while the first light source is dimmed to determine a second set of non-uniformity data and adjust image data obtained from the film in response to the second set of non-uniformity data.

US Patent:

6788335, Sep 7, 2004

Filed:

Dec 21, 2000

Appl. No.:

09/746859

Inventors:

Marc C. Digby - Austin TX
Christopher P. Hansen - Indianapolis IN
Jon Isom - Austin TX
G. Gregory Mooty - Austin TX

Assignee:

Eastman Kodak Company - Rochester NY

International Classification:

H04N 718

US Classification:

348 96, 348 97

Abstract:

One aspect of the invention is a method for signal modulation adjustment. The method comprises illuminating a reference target and a region of film with a first light source for a first time interval. The method further comprises capturing image data from the film in response to a first amount of light reflected from the film with a first sensor for a first integration time. The method also comprises approximately simultaneously producing a first reference output in response to a first amount of light reflected from the reference target in a field of view of a reference sensor. More particularly, the method further comprises adjusting the data in response to the reference output. In a further embodiment, the method comprises adjusting an output illumination level of the first light source in response to the first reference output before a next time interval.

US Patent:

7330501, Feb 12, 2008

Filed:

Jan 15, 2004

Appl. No.:

10/757926

Inventors:

Jason A. Trachewsky - Menlo Park CA, US
Alan Corry - Santa Clara CA, US
Christopher J. Hansen - Sunnyvale CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04B 1/38

US Classification:

375219

Abstract:

A radio frequency integrated circuit includes a transmitter section, and a receiver section. The receiver section includes a low noise amplifier, down conversion module, an orthogonal-normalizing module, and a baseband processor. The low noise amplifier is operably coupled to amplify the inbound RF signals to produce amplified inbound signals. The down conversion module is operably coupled to convert the amplified inbound RF signals into baseband in-phase components and baseband quadrature components. The orthogonal normalizing module is operably coupled to obtain a 1and 2coefficients that are based on at least one of power of the baseband in-phase components, power of the baseband quadrature components, and/or cross-correlation between the baseband in-phase component and baseband quadrature components. The orthogonal normalizing module then normalizes an orthogonal relationship between the in-phase components and quadrature components based on the 1and 2coefficients to produce normalized in-phase components and normalized quadrature components.

US Patent:

7555053, Jun 30, 2009

Filed:

Aug 30, 2004

Appl. No.:

10/929313

Inventors:

Jason A. Trachewsky - Menlo Park CA, US
R. Tushar Moorti - Mountain View CA, US
Christopher J. Hansen - Sunnyvale CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04B 7/02

US Classification:

375267, 375260, 375264, 375299, 375347, 4552261, 455561, 455522, 4555621

Abstract:

A method for configuring a multiple input multiple output (MIMO) wireless communication begins by generating a plurality of preambles for a plurality of transmit antennas. Each of the plurality of preambles includes a carrier detection sequence at a legacy transmit rate, a first channel sounding at the legacy transmit rate, a signal field at the legacy transmit rate, and Z−1 channel soundings at a MIMO transmit rate, where L corresponds to a number of channel soundings. The method continues by simultaneously transmitting the plurality of preambles via the plurality of transmit antennas.

US Patent:

7558537, Jul 7, 2009

Filed:

Apr 11, 2006

Appl. No.:

11/403094

Inventors:

Jason A. Trachewsky - Menlo Park CA, US
Rajendra Tushar Moorti - Mountain View CA, US
Christopher J. Hansen - Sunnyvale CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04B 1/04

US Classification:

455104, 455324, 4555621, 375299, 370350

Abstract:

A programmable transmitter generates a frame preamble to train a receiver with respect to a communication link format that corresponds to a transmission mode wherein the transmission mode may comprise transmitting the communication link over one or more antennas. Generally, the invention includes generating a preamble with an arrangement that depends upon whether a Greenfield (high data rate) or mixed mode transmission is to occur and that depends upon a number of spatial streams that are to be generated. One format for high data rate transmission includes a short training sequence, a long training sequence and a signal field. The mixed mode transmission further includes a legacy prefix.

US Patent:

7974591, Jul 5, 2011

Filed:

Jul 6, 2009

Appl. No.:

12/498351

Inventors:

Jason A. Trachewsky - Menlo Park CA, US
Rajendra Tushar Moorti - Mountain View CA, US
Christopher J. Hansen - Sunnyvale CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04B 1/04

US Classification:

455104, 455324, 4555621, 375299, 370350

Abstract:

A programmable transmitter generates a frame preamble to train a receiver with respect to a communication link format that corresponds to a transmission mode wherein the transmission mode may comprise transmitting the communication link over one or more antennas. Generally, the invention includes generating a preamble with an arrangement that depends upon whether a Greenfield (high data rate) or mixed mode transmission is to occur and that depends upon a number of spatial streams that are to be generated. One format for high data rate transmission includes a short training sequence, a long training sequence and a signal field. The mixed mode transmission further includes a legacy prefix.

US Patent:

8031806, Oct 4, 2011

Filed:

Nov 1, 2010

Appl. No.:

12/916976

Inventors:

Jason A. Trachewsky - Menlo Park CA, US
Rajendra Tushar Moorti - Mountain View CA, US
Christopher Young - Cupertino CA, US
Christopher J. Hansen - Los Altos CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04L 27/00

US Classification:

375299, 375267, 375295, 375130, 375347, 370328, 370344, 370338

Abstract:

A preamble of a frame for a multiple input multiple output (MIMO) wireless communication for a first transmit antenna of the MIMO communication includes a legacy preamble portion in accordance with a legacy wireless communication protocol. The preamble of the frame for the MIMO wireless communication for the first transmit antenna also includes a current protocol preamble portion in accordance with a protocol of the MIMO wireless communication. The preamble of a frame for at least a second antenna of the MIMO communication includes a cyclically shifted legacy preamble portion for the frame. The preamble of the frame for the MIMO wireless communication for the second transmit antenna also includes a second current protocol preamble portion in accordance with a protocol of the MIMO wireless communication.