Chong Doua Lee

US Patent:

6366614, Apr 2, 2002

Filed:

Oct 11, 1996

Appl. No.:

08/731229

Inventors:

Donald T. Pian - San Diego CA
Chong U. Lee - San Diego CA

Assignee:

Qualcomm Inc. - San Diego CA

International Classification:

H04N 712

US Classification:

37524002, 37524022

Abstract:

A system and method for adaptively controlling the encoded data rate in a data compression system. The system and method sets up alternative encoded bit streams for each segment of data and selects the alternative that would produce the bit rate closest to a predetermined target bit rate for transmission. Each segment of video input is quantized based on a set quantization settings to produce a plurality of quantized segments. Each quantized segment is then variable rate encoded to produce an alternative encoded bit stream. The data rate that would be required to transmit each alternative encoded bit stream is determined and compared with a predetermined target bit rate, which is set according to the transmission rate buffer status. The selected encoded bit stream is provided to the transmission rate buffer in preparation for transmission. Having processed one segment of data, the system and method then updates its parameters for processing the next segment of data.

US Patent:

6717908, Apr 6, 2004

Filed:

May 10, 2001

Appl. No.:

09/853341

Inventors:

Rajiv Vijayan - San Diego CA
Joseph P. Odenwalder - Del Mar CA
Jack K. Wolf - La Jolla CA
Chong U. Lee - San Diego CA
Ephraim Zehavi - Haifa, IL

Assignee:

Qualcomm, Incorporated - San Diego CA

International Classification:

H04J 1100

US Classification:

370206, 375316

Abstract:

In an orthogonal frequency division multiplexing (OFDM) system which uses an outer Reed-Solomon encoder and interleaver an inner convolutional encoder, after the inner convolutional encoding the data bits are interleaved, and then grouped into symbols, each symbol having âmâ bits. After grouping, the symbols are mapped to a complex plane using quadrature amplitude modulation (QAM). Thus, bits, not symbols, are interleaved by the inner interleaver. A receiver performs a soft decision regarding the value of each bit in each complex QAM symbol received.

US Patent:

6792542, Sep 14, 2004

Filed:

Nov 8, 2000

Appl. No.:

09/708810

Inventors:

Chong U. Lee - San Diego CA
Katherine S. Lam - San Diego CA
Julien J. Nicolas - San Diego CA
Edward Atrero - San Diego CA

Assignee:

Verance Corporation - San Diego CA

International Classification:

G06K 900

US Classification:

713200, 380 2

Abstract:

A system for embedding auxiliary digital information (D ) into an existing primary digitally encoded signal (X ) to form an unobjectionable composite digital signal (C ). Auxiliary data bits (D ) modulate a pseudo-random (e. g. , PN) sequence ( ) to provide an auxiliary data sequence ( ) that is used to modify the Least Perceptually Significant Bits (LPSBs) ( ) of successive multi-bit samples ( ) of the primary signal. In a cross-term compensation embodiment ( ), a correlation (V) between the PN sequence and the sample bits is determined, and compared to the auxiliary data bits (D ) to determine whether there is a desired correspondence. The LPSBs in the samples are toggled ( ), if necessary, to provide the desired correspondence. The selection of LPSBs to modify accounts for a desired noise level of the auxiliary data (D ) in the primary signal (X ). LPSBs may be selected to be modified based on a sparse PN sequence ( ) to achieve the desired noise level and to conceal the presence of the auxiliary data (D ).

US Patent:

6888943, May 3, 2005

Filed:

Oct 19, 2000

Appl. No.:

09/692084

Inventors:

Katherine S. Lam - San Diego CA, US
Kamran Moallemi - Del Mar CA, US
Chong U. Lee - San Diego CA, US
Taku Katoh - Kanagawa, JP
Naoki Endoh - Tokyo, JP

Assignee:

Verance Corporation - San Diego CA

International Classification:

H04L009/00
H04N007/167
H03K017/92

US Classification:

380268, 380217, 380213, 380210, 380215, 327371

Abstract:

A system () for scrambling digital samples () of multimedia data, including audio and video data samples, such that the content of the samples is degraded but still recognizable, or otherwise provided at a desired quality level. The samples may be in any conceivable compressed or uncompressed digital format, including Pulse Code Modulation (PCM) samples, samples in floating point representation, samples in companding schemes (e. g. , μ-law and A-law), and other compressed bit streams. The quality level may be associated with a particular signal to noise ratio, or quality level that is determined by objective and/or subjective tests, for example. A number of LSBs can be scrambled in successive samples in successive frames (FRAME A, FRAME B, FRAME C). Moreover, the parameters for scrambling may change from frame to frame. Furthermore, all or part of the scrambling key () can be embedded () in the scrambled data and recovered at a decoder () to be used in descrambling.

US Patent:

6912315, Jun 28, 2005

Filed:

Nov 22, 2000

Appl. No.:

09/721015

Inventors:

Douglas Wong - San Diego CA, US
Chong U. Lee - San Diego CA, US

Assignee:

Verance Corporation - San Diego CA

International Classification:

G06K009/36
H04N001/36
H04N009/74

US Classification:

382232, 358409, 348594

Abstract:

Auxiliary information () representing binary or multi-level (M≧2) logical values is embedded into successive segments () of an audio, video or other data signal in response to a user request to download the data signal via an on-line distributor () on a computer network such as the Internet. To avoid unnecessary delays in providing the data signal to the user, the data signal is pre-processed to provide two sets or copies of data (). One set () of the data contains segments with an embedded binary “0”, while the other set () contains corresponding segments with an embedded binary “1”. Successive segments are selected from one of the two sets to provide a time-multiplexed composite data signal () that has the desired content, but with an embedded binary data sequence that identifies the user.

US Patent:

7023915, Apr 4, 2006

Filed:

Jul 16, 2001

Appl. No.:

09/907153

Inventors:

Donald T. Pian - San Diego CA, US
Chong U. Lee - San Diego CA, US

Assignee:

Qualcomm, Incorporated - San Diego CA

International Classification:

H04N 7/12

US Classification:

37524002

Abstract:

A system and method for adaptively controlling the encoded data rate in a data compression system. The system and method sets up alternative encoded bit streams for each segment of data and selects the alternative that would produce the bit rate closest to a predetermined target bit rate for transmission. Each segment of video input is quantized based on a set quantization settings to produce a plurality of quantized segments. Each quantized segment is then variable rate encoded to produce an alternative encoded bit stream. The data rate that would be required to transmit each alternative encoded bit stream is determined and compared with a predetermined target bit rate, which is set according to the transmission rate buffer status. The selected encoded bit stream is provided to the transmission rate buffer in preparation for transmission. Having processed one segment of data, the system and method then updates its parameters for processing the next segment of data.

US Patent:

7460667, Dec 2, 2008

Filed:

May 26, 2004

Appl. No.:

10/854457

Inventors:

Chong U. Lee - San Diego CA, US
Katherine S. Lam - San Diego CA, US
Julien J. Nicolas - San Diego CA, US
Edward Atrero - San Diego CA, US

Assignee:

Verance Corporation - San Diego CA

International Classification:

H04N 7/167

US Classification:

380205, 713200

Abstract:

A system for embedding auxiliary digital information into a primary digital signal to form a composite digital signal. Auxiliary data bits modulate a pseudo-random (e. g. , PN) sequence to provide an auxiliary data sequence used to modify the Least Perceptually Significant Bits (LPSBs) of successive multi-bit samples of the primary signal. In a cross-term compensation embodiment, a correlation between the PN sequence and the sample bits is determined, and compared to the auxiliary data bits to determine whether there is a desired correspondence. The LPSBs in the samples are toggled, if necessary, to provide the desired correspondence. The selection of LPSBs to modify accounts for a desired noise level of the auxiliary data in the primary signal. LPSBs may be modified based on a sparse PN sequence to achieve the desired noise level and conceal the presence of the auxiliary data.

US Patent:

7576605, Aug 18, 2009

Filed:

Apr 19, 2007

Appl. No.:

11/737678

Inventors:

Chong U. Lee - San Diego CA, US
David Jonathan Julian - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H03F 3/38

US Classification:

330 10, 330207, 330251, 341143, 341177, 341182, 341189, 341190

Abstract:

Power consumption of an output stage such as a class-D output stage may depend on the amplitude and the activity of the signal being output. Here, control signals may be generated to independently control coupled switches of the output stage and to provide a tri-state control scheme for the output stage. These control signals may be generated based on durations of different levels of an input signal over one or more periods of time.