Dennis Hui from San Carlos, CA, age 55

Resumes

Software Developer At Fiserv (Previous M-Com)

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Position:

Software Developer at Fiserv

Location:

Auckland, New Zealand

Industry:

Information Technology and Services

Work:

Fiserv since Jun 2011
Software Developer
SKYCITY Feb 2008 - Jun 2009
chef

Education:

The University of Auckland 2010 - 2011
Bachelor of Science (B.S.), Computer Programming

Skills:

Scrum
Java
Objective-C
iOS development
Android Development
PhoneGap
JavaScript
HTML
CSS

Languages:

Chinese
English

Certifications:

Java SE 6 Programmer Certified Professional, Oracle

Publications

Us Patents

Methods, Receiver Devices And Systems For Whitening A Signal Disturbance In A Communication Signal

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US Patent:

6590932, Jul 8, 2003

Filed:

Nov 24, 1999

Appl. No.:

09/450684

Inventors:

Dennis Hui - Cary NC
Kambiz C. Zangi - Durham NC
Rajaram Ramesh - Cary NC

Assignee:

Ericsson Inc. - Research Triangle Park NC

International Classification:

H03H 1704

US Classification:

375232, 375284, 375285, 375348, 375350, 708322, 329320, 329353

Abstract:

Methods, systems and receiver devices are provided which may reduce the average power of a signal disturbance by whitening the signal disturbance. In one aspect, a finite impulse response filter (FIR) is provided which whitens the signal disturbance by filtering a downsampled received signal using filter coefficients adaptively established using known signal information in each signal burst of the received signal. Alternatively, a noise-whitening equalizer is utilized having a modified metric that whitens the signal disturbance again using coefficients adaptively established using known signal information in each signal burst of the received signal. The noise-whitening equalizer approach further allows the noise-whitening coefficients to be updated by treating symbol estimates from the equalizer as known signal information to generate updated noise-whitening coefficients. A novel receiver containing a modified Euclidean metric equalizer to provide noise-whitening is also provided.

Method And Apparatus For Computing Prefilter Coefficients

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US Patent:

6608862, Aug 19, 2003

Filed:

Aug 20, 1999

Appl. No.:

09/378314

Inventors:

Kambiz C. Zangi - Durham NC
Dennis Hui - Cary NC

Assignee:

Ericsson, Inc. - Research Triangle Park NC

International Classification:

H03H 730

US Classification:

375232, 375233, 708323

Abstract:

The impulse response of a prefilter used with a DFSE equalizer in a receiver system is computed. A channel estimate is determined in response to signals received by the receiver system. The channel estimate may include a forward channel estimate and a backward channel estimate. Roots of a z-transform of the forward channel estimate and roots of a z-transform of the backward channel estimate are determined. Those roots of the z-transform of the forward channel estimate having a magnitude greater than one are used to form a z-transform of a forward impulse response of the prefilter while those roots of the z-transform of the backward channel estimate having a magnitude greater than one are used to form a z-transform of a backward impulse response of the prefilter. Forward prefilter coefficients for the prefilter are computed based on the z-transform of the forward impulse response of the prefilter and backward prefilter coefficients for the prefilter are computed based on the z-transform of the backward impulse response of the prefilter. A forward impulse response of a forward composite channel are computed based on the forward prefilter coefficients while a backward impulse response of a backward composite channel are computed based on the backward prefilter coefficients.

Receiver Devices, Systems And Methods For Receiving Communication Signals Subject To Colored Noise

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US Patent:

6674820, Jan 6, 2004

Filed:

Feb 15, 2000

Appl. No.:

09/504216

Inventors:

Dennis Hui - Cary NC
Kambiz C. Zangi - Durham NC

Assignee:

Ericsson Inc. - Research Triangle Park NC

International Classification:

H03D 104

US Classification:

375346

Abstract:

Methods, systems and receiver devices are provided which may provide improved receiver performance in obtaining estimates of the complex-valued baseband channel in the presence of colored baseband noise. In various embodiments of the present invention, systems and methods are provided in which, over each synchronization signal period or other determinate information window, the channel coefficients and the color of the baseband noise are concurrently estimated. Thus, both the channel coefficients and the color of the noise are estimated, rather than assuming white noise, and channel coefficients may be provided that account for the color of the noise These estimates may be provided for each burst of a communication and may result in an improved channel estimate in the presence of colored noise. The baseband noise can become colored due to, for example, having a non-Nyquist receive filter, due to the presence of a colored co-channel interferer, or due to the presence of an adjacent channel interferer. The concurrent estimates of the color of the noise and channel coefficients may be provided iteratively or by selection of a best result among a plurality of candidate noise color assumptions.

Methods, Receivers And Equalizers Having Increased Computational Efficiency

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US Patent:

6707849, Mar 16, 2004

Filed:

Feb 8, 2000

Appl. No.:

09/499977

Inventors:

Kambiz C. Zangi - Durham NC
Rajaram Ramesh - Cary NC
Dennis Hui - Cary NC

Assignee:

Ericsson Inc. - Research Triangle Park NC

International Classification:

H04L 2503

US Classification:

375233, 375262, 375341, 375346, 714792, 714794, 714795, 714796

Abstract:

Metrics associated with each branch from a previous hypothesized trellis state to each respective possible current trellis state in a DFSE equalizer can be calculated. In particular, a common portion of branch metrics can be calculated that is common to each of the branch metrics from the previous hypothesized state to each of the current possible states, and difference variables representing a difference between the common portion of the branch metrics and each of the branch metrics from the previous hypothesized state to each of the current possible states can also be calculated. The common portion of the branch metrics and each of the difference variables can then be combined to provide a respective metric for each of the possible current states.

Time Interval Based Channel Estimation With Transmit Diversity

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US Patent:

6711124, Mar 23, 2004

Filed:

May 25, 2001

Appl. No.:

09/866241

Inventors:

Ali S. Khayrallah - Apex NC
Dennis Hui - Cary NC

Assignee:

Ericsson Inc. - Research Triangle Park NC

International Classification:

H04Q 700

US Classification:

370208, 370345, 375347

Abstract:

A wireless communication system with transmit diversity scales a training sequence simultaneously transmitted by two or more antennas over two or more time intervals in a manner that allows a receiver to perform channel estimation relative to each antenna. The transmit signal is scaled at each antenna in each time interval by a corresponding scaling value selected from a set of orthogonal scaling values. The receiver develops a channel estimate for each of the time intervals as if there were only one antenna transmitting the training sequence. These channel estimates are then summed or combined for each transmit antenna, using values from the corresponding scaling value matrix column. The orthogonality between scaling value sequences used between the multiple transmit antennas allows the receiver to distinguish the training sequence as received from the individual transmit antennas, and to thus perform channel estimation with respect to each transmit antenna.

Offset Local Oscillator Frequency

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US Patent:

6725024, Apr 20, 2004

Filed:

Nov 7, 2000

Appl. No.:

09/706744

Inventors:

Bengt Lindoff - BjÃ¤rred, SE
Dennis Hui - Cary NC
Kambiz Casey Zangi - Durham NC

Assignee:

Telefonaktiebolaget LM Ericsson (publ) - Stockholm

International Classification:

H04B 106

US Classification:

455255, 455318, 455323, 375344

Abstract:

A method and apparatus for offsetting the frequency of a local oscillator in a receiver are disclosed. The local oscillator frequency is offset with an offset frequency that depends on the training sequence used. Training symbols are inputted to the control unit. The control unit then provides an offset frequency depending on the training symbol received. A rotation of the baseband signal, proportional to the offset frequency, is introduced which later is digitally compensated for. Upon reception of the signal, a DC offset is introduced in the radio part. The digital compensation transforms this DC offset, in the baseband signal, to a rotating signal. The rotating DC offset signal is then subtracted in the baseband processing.

Equalizer With Adaptive Pre-Filter

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US Patent:

6775322, Aug 10, 2004

Filed:

Aug 14, 2000

Appl. No.:

09/638718

Inventors:

Kambiz C. Zangi - Durham NC
Raymond Toy - Cary NC
Dennis Hui - Cary NC

Assignee:

Ericsson Inc. - Research Triangle Park NC

International Classification:

H03H 730

US Classification:

375232, 375233, 708323

Abstract:

A computationally efficient method for computing the filter coefficients for a prefilter in a decision feedback equalizer solves linear equations using a fast Toeplitz algorithm. Computations performed to compute the filter coefficients for the right half burst may be used to compute the prefilter for the left hand burst, thereby reducing the number of computations. Also, a square root-free algorithm may be used to solve the system of linear equations, further reducing computational complexity.

Methods For Receiving Diversity Transmissions Including Prefiltering To Provide Minimum Phase Channel Characteristics And Related Receivers

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US Patent:

6778619, Aug 17, 2004

Filed:

May 11, 2001

Appl. No.:

09/853207

Inventors:

Kambiz C. Zangi - Durham NC
Dennis Hui - Cary NC

Assignee:

Ericsson Inc. - Research Triangle Park NC

International Classification:

H04L 102

US Classification:

375347, 375232, 455132

Abstract:

A method for receiving transmissions includes receiving a first symbol-spaced baseband signal corresponding to first portions of first and second encoded data sequences transmitted over first and second baseband channels, and receiving a second symbol-spaced baseband signal corresponding to second portions of the first and second encoded data sequences transmitted over the first and second baseband channels. The first and second symbol-spaced baseband signals are combined to provide a combined baseband signal, and the combined baseband signal is prefiltered to provide minimum phase channel characteristics. The prefiltered combined baseband signal is equalized to provide an estimate of a data sequence. Related receivers are also discussed.

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