Timothy A Thomas

US Patent:

6362781, Mar 26, 2002

Filed:

Jun 30, 2000

Appl. No.:

09/607736

Inventors:

Timothy A. Thomas - Palatine IL
Frederick W. Vook - Schaumburg IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

G01S 328

US Classification:

342383, 342367

Abstract:

A receiving device and method for operating a communication system are provided. The receiving device receives a plurality of time-domain Doppler channel estimates for at least one transmitter, a plurality of Doppler sinusoids, and a spatial covariance matrix of a corrupting environment. A Doppler spatial covariance matrix is created as a function of the time-domain Doppler channel estimates and the Doppler sinusoids. A total Doppler spatial covariance matrix is created as a function of the spatial covariance matrix of the corrupting environment and the Doppler spatial covariance matrix. A Doppler steering vector is created for at least one transmitter as a function of the Doppler channel estimates and the Doppler sinusoids. A combining weight for the at least one transmitter is then created as a function of the total Doppler spatial covariance matrix and the Doppler steering vector for at least one transmitter.

US Patent:

6445342, Sep 3, 2002

Filed:

Jun 30, 2000

Appl. No.:

09/608760

Inventors:

Timothy A. Thomas - Palatine IL
Frederick W. Vook - Schaumburg IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04B 700

US Classification:

342367

Abstract:

The present invention is a technique of estimating the time and frequency response of at least one desired signal received by at least one antenna. The invention is an update formula for the time-invariant channel responses for multiple transmitting devices, called âDoppler channelsâ, that model the time-varying channel between each of the transmitting devices and each receiving device. Through use of the update formula, the time-varying channels of the multiple transmitting devices can be better tracked than with prior inventions.

US Patent:

6504506, Jan 7, 2003

Filed:

Jun 30, 2000

Appl. No.:

09/607733

Inventors:

Timothy A. Thomas - Palatine IL
Frederick W. Vook - Schaumburg IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

G01S 328

US Classification:

342383, 342367

Abstract:

A receiving device and method for operating a communication system are provided. The receiving device receives at least one Doppler channel estimate for at least one transmitter and a spatial covariance matrix of a corrupting environment. The Doppler channel estimates are used to create a Null Doppler spatial covariance matrix. A total Doppler spatial covariance matrix is created as a sum of the spatial covariance matrix of the corrupting environment, plus the Doppler spatial covariance matrix. A combining weight for at least one transmitter and at least one Doppler channel is created from the total Doppler spatial covariance and the at least one Doppler channel for the at least one transmitter.

US Patent:

6640088, Oct 28, 2003

Filed:

Dec 14, 2001

Appl. No.:

10/017731

Inventors:

Timothy A. Thomas - Palatine IL
Xiangyang Zhuang - Hoffman Estates IL
Frederick W. Vook - Schaumburg IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04B 1700

US Classification:

455 6711, 455 6714, 455 6713, 455 6716, 375340, 375148

Abstract:

The invention provides a method of determining an adaptive channel estimation by providing a channel estimate, determining at least one channel condition, and determining an adapted channel estimate as a function of the channel estimate and the channel condition.

US Patent:

6647078, Nov 11, 2003

Filed:

Jun 30, 2000

Appl. No.:

09/608582

Inventors:

Timothy A. Thomas - Palatine IL
Frederick W. Vook - Schaumburg IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04B 110

US Classification:

375349, 375346, 375285, 455 63, 4552781

Abstract:

The invention is a method of estimating the time and frequency response of at least one desired signal received by at least one antenna, based on Gradient Optimization techniques. Through the use of gradient optimization techniques and efficient DFT processing, the invention provides frequency response estimates that require fewer computations than prior art decision-directed channel estimation devices.

US Patent:

6765969, Jul 20, 2004

Filed:

Aug 22, 2000

Appl. No.:

09/643541

Inventors:

Frederick W. Vook - Schaumburg IL
Timothy A. Thomas - Palatine IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04L 2700

US Classification:

375259, 375295, 375316

Abstract:

The invention computes frequency-domain channel gains by compiling a set of estimated channel gains as a function of pilot sequences, a set of analytical channel gains variables, and a set of weighting coefficients variables. A plurality of weighting coefficients are computed as a function of time and frequency correlation functions, a noise correlation matrix, and pilot sequences. A weighting matrix is computed from the weighting coefficients. After receiving a training sequence from at least one transmitter, a received data matrix is computed from the training sequence. The weighting matrix and the received data matrix are used to compute the frequency-domain channel gains. The invention also provides a method for reducing the computational complexity of estimating the time and frequency response of at least one desired signal received by at least one antenna. Also, the time and frequency response of at least one desired signal received by at least one antenna can be both interpolated and predicted with the present invention.

US Patent:

6826240, Nov 30, 2004

Filed:

Mar 15, 2000

Appl. No.:

09/526003

Inventors:

Timothy A. Thomas - Palatine IL
Frederick W. Vook - Schaumburg IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04L 2706

US Classification:

375340, 375347

Abstract:

A receiving device and method for operating a communication system is provided. The receiving device receives a predetermined pilot sequence. The received pilot sequence is converted into at least one frequency domain pilot sequence. A plurality of time invariant channel estimates are determined from the frequency domain pilot sequence. The pilot sequence may include a null cyclic prefix. A time variant channel estimate may be determined from the time invariant channel estimates.

US Patent:

6834043, Dec 21, 2004

Filed:

Jul 24, 2000

Appl. No.:

09/624453

Inventors:

Frederick W. Vook - Schaumburg IL
Timothy A. Thomas - Palatine IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04J 1100

US Classification:

370310, 370203, 370335, 370342, 375295, 375347, 455 65, 455 69

Abstract:

A method of operating a communication system including at least two transmitting antennas and at least one receive antenna. Symbols are encoded across the at least two transmitting antennas during a coding interval. Data is received at each receive antenna and at each symbol of the coding interval. Channel gain estimates are provided between each transmitting antenna and each receive antenna at each symbol of the coding interval. An estimate of transmitted symbols is determined based on the channel gain estimates and the received data at each receive antenna at each symbol of the coding interval. An information unit is provided the estimates of the transmitted symbols to achieve spatial diversity in a communication link while mitigating channel variations.