Heejong Yoo

US Patent:

8498407, Jul 30, 2013

Filed:

Dec 2, 2008

Appl. No.:

12/326868

Inventors:

Asif Iqbal Mohammad - San Diego CA, US
Eddie L. T. Choy - Carlsbad CA, US
Heejong Yoo - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04M 9/08

US Classification:

37940608, 37940612

Abstract:

A communications device that is configured to detect double talk is described. An echo canceller is configured to cancel an echo from an input signal using an adaptive filter. A double-talk detector provides a double-talk statistic. The double-talk statistic is proportional to the ratio of the remaining echo energy in the cancellation error signal and the total cancellation error energy.

US Patent:

8600038, Dec 3, 2013

Filed:

Sep 4, 2008

Appl. No.:

12/204608

Inventors:

Asif Iqbal Mohammad - San Diego CA, US
Steven L. Grant - Rolla MO, US
Heejong Yoo - San Diego CA, US
Deepak Kumar Challa - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04M 9/08
A61F 2/20
H04B 3/20
H04B 1/38

US Classification:

37940609, 381 7112, 370290, 455570

Abstract:

An echo canceller for improved recognition and removal of an echo from a communication device. The echo canceller can dynamically reduce echo using an improved energy estimator and an improved adaptive filter. The improved energy estimator can determine if conversation is in a single talk period or a double talk period based on the combined energy of both the near end background noise and speech. The improved adaptive filter can reduce echo by dynamically changing adaptation speed or step size. In double talk, the adaptive filter(s) can dynamically slow-down or stop adaptation. In single talk, the filter can dynamically increase the speed of adaptation to improve accuracy, or decrease adaptation speed for stability.

US Patent:

20040013276, Jan 22, 2004

Filed:

Mar 21, 2003

Appl. No.:

10/394783

Inventors:

Richard Ellis - Phoenix AZ, US
Heejong Yoo - Atlanta GA, US
David Graham - Marlton NJ, US
Paul Hasler - Atlanta GA, US
David Anderson - Alpharetta GA, US

International Classification:

H04B015/00

US Classification:

381/094300, 381/094100

Abstract:

One preferred embodiment of the present invention provides systems and methods for removing noise from an input analog signal in continues time. Briefly described in architecture, one embodiment of the system, among others, can be implemented as follows. An analog filtering system including VLSI circuitry separates an analog input signal into a plurality of sub-band signals. Then, an analog gain system including VLSI circuitry calculates a gain for each sub-band signal that suppresses the noise within the sub-band signal. In some preferred embodiments, VLSI circuitry includes floating gate technology. Methods and other systems are also provided.

US Patent:

20050201457, Sep 15, 2005

Filed:

Mar 10, 2005

Appl. No.:

11/076741

Inventors:

Daniel Allred - Douglasville GA, US
David Anderson - Alpharetta GA, US
Walter Huang - Greer SC, US
Venkatesh Krishnan - Atlanta GA, US
Heejong Yoo - San Diego CA, US

International Classification:

H03K005/159

US Classification:

375232000

Abstract:

Systems and methods for very high throughput adaptive filtering using distributed arithmetic are disclosed. One distributed arithmetic adaptive filter may include a memory for storing a first and second lookup table. The first lookup table may include 2filter weights addressed by the rightmost bits of each of K signal samples stored in a plurality of registers. The filter may include a controller configured to update the second lookup table with each possible combination of the sums of the K most recent input samples and update each of the 2filter weights of the first lookup table based on the combination of the sums of the K most recent input samples stored in the second lookup table. The second lookup-table may be updated during a filtering operation that uses the first lookup-table. One filter may include a plurality of sub-filters with each sub-filter having first and second lookup tables.

US Patent:

20090070119, Mar 12, 2009

Filed:

Sep 4, 2008

Appl. No.:

12/204593

Inventors:

Heejong Yoo - San Diego CA, US
Nidish R. Kamath - San Diego CA, US
Eddie L.T. Choy - Carlsbad CA, US
Johnny Kallacheril John - San Diego CA, US
Samir K. Gupta - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

G10L 19/00

US Classification:

704500, 704E19001

Abstract:

Power savings in a mobile device is accomplished by generating audio samples by decoding a bitstream with a decoding system within the mobile device. The generated audio samples are transferred into at least one memory bank in a set of memory banks in a power saver block within the mobile device. Parts of the decoding system not involved in the storing of the generated audio samples are switched off after batch decoding a bitstream associated with multiple audio frames. The bitstream includes bits less than that found in one audio file. At least one of the memory banks in the set of memory banks is power collapsible. The fetching of the decoded by the decoding system can be synchronized with a paging channel of a modem in the mobile device. The transferred audio samples is a lossless compression and may occur after a re-encoding.

US Patent:

20100017196, Jan 21, 2010

Filed:

Jul 16, 2009

Appl. No.:

12/504592

Inventors:

Sang-Uk Ryu - San Diego CA, US
Samir K. Gupta - San Diego CA, US
Philip Rutschman - Seattle WA, US
Heejong Yoo - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

G10L 19/00

US Classification:

704201, 704E19004

Abstract:

Embodiments of methods, apparatuses, devices and systems associated with compression and decompression of digital signals are disclosed.

US Patent:

20120078397, Mar 29, 2012

Filed:

Mar 30, 2011

Appl. No.:

13/076242

Inventors:

Khaled Helmi EL-MALEH - San Marcos CA, US
Heejong YOO - San Diego CA, US
Jongwon SHIN - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

G06F 17/00

US Classification:

700 94

Abstract:

A mobile device that is capable of automatically starting and ending the recording of an audio signal captured by at least one microphone is presented. The mobile device is capable of adjusting a number of parameters related with audio logging based on the context information of the audio input signal.