Don Li from Staten Island, NY

Sliding Matched Filter With Flexible Hardware Complexity

View page

US Patent:

6714586, Mar 30, 2004

Filed:

May 10, 2001

Appl. No.:

09/852085

Inventors:

Gang Yang - Eatontown NJ
Don Li - Morganville NJ

Assignee:

Golden Bridge Technology Incorporated - West Long Branch NJ

International Classification:

H04B 1707

US Classification:

375148, 375149, 375152

Abstract:

Multi-path effects are common in mobile communications. When coupled with spread-spectrum signals utilizing spreading code sequences, detection of more than one multi-path signal becomes a necessity in order to output a clean signal with little loss. In accord with the invention, a spread-spectrum sliding matched-filter searcher system comprises a partial matched-filter that receives the input spread-spectrum signal. The searcher matches samples of the input signal with a tap length m of the reference code and produces a first correlation value. The first correlation value is compared to a first threshold. When it equals or exceeds the first threshold, the first correlation value is integrated to produce a second correlation value. This second value is compared with a second threshold, which if met signifies the detection of the multi-path signal. The process is repeated until all significant multi-path signals are detected.

Programmable Matched Filter Bank

View page

US Patent:

6842480, Jan 11, 2005

Filed:

Sep 14, 2000

Appl. No.:

09/662148

Inventors:

Gang Yang - Eatontown NJ, US
Don Li - Morganville NJ, US

Assignee:

Golden Bridge Technology Incorporated - West Long Branch NJ

International Classification:

H04B 169

US Classification:

375152, 375143, 375343

Abstract:

A programmable matched filter bank comprises a sliding integrator and compensation calculation circuits. The integrator receives a chip stream of samples derived from a received spread-spectrum signal and integrates a number of the most recent samples, to form a common integration value. Each of the compensation calculation circuits receives the same most recent samples and receives a respective one of the possible reference spreading code sequences. In operation, each compensation calculation circuit derives a compensation value, and an associated circuit modifies the common integration value by the respective compensation value. The result is a value of correlation between the predetermined number of most recent samples, for each respective reference code sequence. The inventive approach reduces the number of bit adders and inverters in the implementation of a matched-filter, a programmable matched filter and a programmable matched filter bank for spread spectrum receivers.

Method And Apparatus Of A Fast Two-Loop Automatic Gain Control Circuit

View page

US Patent:

6843597, Jan 18, 2005

Filed:

May 15, 2001

Appl. No.:

09/854620

Inventors:

Don Li - Morganville NJ, US
Gang Yang - Freehold NJ, US

Assignee:

Golden Bridge Technology Inc. - West Long Branch NJ

International Classification:

H04L 2708

US Classification:

374345

Abstract:

In a burst-mode, high-speed spread-spectrum communications system, faster convergence of a receiver's automatic gain control (AGC) circuit reduces the time required to bring a received signal within the operating range of an operation amplifier and other radio-frequency and digital sections of the receiving system. A gain control circuit includes a coarse-gain feedback loop and a fine-gain feedback loop to improve convergence speed and at the same time maintain the stability of the AGC circuit. The coarse-gain feedback loop quickly brings the received signal, using a large gain signal, to the desired operating range. The fine-gain feedback loop uses a smaller gain signal to gradually smooth the received signal to avoid saturation on the A/D converters.

Power-Controlled Random Access

View page

US Patent:

6937641, Aug 30, 2005

Filed:

Feb 27, 2002

Appl. No.:

10/083687

Inventors:

Don Li - Morganville NJ, US
Gang Yang - Eatontown NJ, US

Assignee:

Golden Bridge Technology, Inc. - West Long Branch NJ

International Classification:

H04K001/00
H04B001/707

US Classification:

375141, 370342

Abstract:

A novel power-controlled random-access method allows a mobile station to gain fast access to the base station. At the mobile station, a composite power control command is devised after an initial access attempt. The determination of the composite command uses an open-loop power-control symbol and a closed-loop power-control symbol, to decide the action of the mobile station upon transmission of its next random-access signal. In the preferred embodiment, the composite power control command can specify different levels of increase or decrease in transmission power, and the composite power control command can specify a back-off by the mobile station. This composite power-control mechanism can help resolve collision between mobile stations accessing the same random access sub-channel and therefore maintain a low-delay in the random-access process and a high-utilization on the access-channel resource.

Multi-Channel Spread Spectrum System

View page

US Patent:

6993065, Jan 31, 2006

Filed:

Oct 5, 2001

Appl. No.:

09/970888

Inventors:

Don Li - Morganville NJ, US
Gang Yang - Eatontown NJ, US

Assignee:

Golden Bridge Technology Inc. - West Long Branch NJ

International Classification:

H04B 1/707

US Classification:

375146, 375140, 375308

Abstract:

A multi-channel spread-spectrum system separates a data stream, for example from a convolutional encoder and an interleaver, into sub-channel data-sequence signals. For each sub-channel data-sequence signal, m bits are translated to one code of a unique set of orthogonal chip-sequence signals. The other k bits of the same sub-channel data-sequence signal are translated to a distinct phasor. Each phasor is used to modulate the respective chip-sequence signal. A complex-signal combiner combines the real and imaginary components of all the phase-modulated chip-sequence signals into in-phase (I) and quadrature (Q) spread-spectrum multi-channel signals, which are spread by a cell-site specific signature-sequence. The receiver decorrelates the received spread-spectrum signal, preferably with a bank of matched filter (MF) joint-detectors, to recover the bits from all the spread-spectrum sub-channel signals for remultiplexing into the transmitted data stream. The multi-channel spread-spectrum system supports constant data rate throughout the cell by maintaining a large processing gain, at the demultiplexed sub-channel data sequence level, thus a code-reuse-one type spread-spectrum system can be deployed with the aid of power control.

Adaptive Power And Data Rate Control For Ad-Hoc Mobile Wireless Systems

View page

US Patent:

7983230, Jul 19, 2011

Filed:

Jul 11, 2007

Appl. No.:

11/775988

Inventors:

Don Li - Franklin Park NJ, US
Kristina Carlin - Pearl River NY, US

Assignee:

ITT Manufacturing Enterprises, Inc. - Wilmington DE

International Classification:

H04W 4/00
H04L 12/40
H04L 12/413

US Classification:

370338, 370445, 370439

Abstract:

A method for controlling transmit power of a node in wireless network, such as, e. g. , an ad-hoc wireless network operating in accordance with a carrier sense multiple access (CSMA) protocol and where asymmetrical radio links may exist. During a request to send (RTS) and clear to send (CTS) exchange between a first node and a second node, both a request to send (RTS) packet and a probing request to send (PrRTS) packet are transmitted from the first node to the second node. The transmit power and data rate of the PrRTS packet may be different from the transmit power and data rate of the RTS packet. In response, the second node returns a CTS packet that includes a signal to noise ratio (SNR) for both the RTS packet and the PrRTS packet. A correction factor for data transmit power is then computed based in part on both the SNR for the RTS and the SNR for the PrRTS, and a data packet is thereafter transmitted at a power level that has been modified in accordance with the correction factor. The correction factor may further aid the estimation of the signal-to-noise-and-interference ratio (S/(N+I)) at a receiving node, which enables a sending node either to overcome the interference by adjusting the transmit power or avoid the interference by not accessing the channel until it hears the node again.

Sectorized Smart Antenna System And Method

View page

US Patent:

20010033600, Oct 25, 2001

Filed:

Dec 6, 2000

Appl. No.:

09/729694

Inventors:

Gang Yang - Eatontown NJ, US
Don Li - Morganville NJ, US
Elmer Yuen - Hong Kong SAR, CN

Assignee:

Golden Bridge Technology Inc.

International Classification:

H04K001/00
H04B015/00
H04L027/30
H01Q003/00

US Classification:

375/130000, 342/359000

Abstract:

A sectorized smart antenna system includes multiple sector antennas with a software control algorithm for flexible association of physical antennas to a logical serving sector to provide signal coverage in a particular region of the cell served by the base station. The control algorithm can adapt to different situations without requiring any, or only very limited, physical hardware changes to reconfigure a base station to balance the traffic load throughout the cell. The smart antenna system and method includes measuring and recording a mobile station's signal strengths and its rate of changes received by an antenna in a serving sector relative to other antennas in either the same serving sector or different serving sector to determine the mobile station location and its movement, determining when a threshold signal level is reached, and handing-off the mobile station to an adjacent antenna, serving sector, or cell.

Sliding Matched Filter With Flexible Hardware Complexity

View page

US Patent:

20040179585, Sep 16, 2004

Filed:

Mar 26, 2004

Appl. No.:

10/809361

Inventors:

Gang Yang - Eatontown NJ, US
Don Li - Morganville NJ, US

Assignee:

GOLDEN BRIDGE TECHNOLOGY INC. - West Long Branch NJ

International Classification:

H04B001/707

US Classification:

375/148000, 375/150000, 375/152000

Abstract:

Multi-path effects are common in mobile communications. When coupled with spread-spectrum signals utilizing spreading code sequences, detection of more than one multi-path signal becomes a necessity in order to output a clean signal with little loss. In accord with the invention, a spread-spectrum sliding matched-filter searcher system comprises a partial matched-filter that receives the input spread-spectrum signal. The searcher matches samples of the input signal with a tap length m of the reference code and produces a first correlation value. The first correlation value is compared to a first threshold. When it equals or exceeds the first threshold, the first correlation value is integrated to produce a second correlation value. This second value is compared with a second threshold, which if met signifies the detection of the multi-path signal. The process is repeated until all significant multi-path signals are detected. This design of the present invention is flexible in nature because the searcher can be programmed to act like a matched-filter, a correlator, or a combination of both while significantly improving the search time and reducing the amount of hardware and complexity characteristic of a matched-filter.