Steve F Russell

US Patent:

6377116, Apr 23, 2002

Filed:

May 8, 2000

Appl. No.:

09/566642

Inventors:

S. Anders Mattsson - Maineville OH
Steve F. Russell - Ames IA

Assignee:

Iowa State University Research Foundation, Inc. - Ames IA

International Classification:

H03F 126

US Classification:

330 2, 330149

Abstract:

A method of deriving a pre-distorter for a corresponding non-linear amplifier is disclosed. The first step of the method is to form the pre-distorters topology. This is done by first determining a corresponding inverse topology to the non-linear amplifiers topology. The non-linear amplifier has a topology comprising filter and non-linear amplifier elements. The inverse topology comprises corresponding inverse filter and amplifier elements to the amplifiers filter and non-linear amplifier elements. Then, those of the inverse filter and amplifier elements for which compensation with the pre-distorter is desired are selected. Any of the inverse filter and amplifier elements that were not selected are then removed from the inverse topology to form the pre-distorters topology. Thus, the pre-distorters topology comprises the selected inverse filter and amplifier elements. After the pre-distorters topology is determined, a predefined input signal is applied to the non-linear amplifier.

US Patent:

6865215, Mar 8, 2005

Filed:

Feb 16, 2000

Appl. No.:

09/505463

Inventors:

Steve F. Russell - Ames IA, US
Michael L. Hageman - Ely IA, US

Assignee:

Iowa State University Research Foundation, Inc. - Ames IA

International Classification:

H04B001/713

US Classification:

375133, 375135

Abstract:

A digital data communication overlay system is disclosed which is overlaid on a predefined frequency band of an existing analog data communication system. The digital data communication overlay system comprises a digital mobile unit and a digital ground station. The digital mobile unit and the digital ground station are configured to transmit and receive spread spectrum digital data communication signals between each other over the same spread spectrum digital channel. This is done by spreading the spread spectrum digital data communication signals over the predefined frequency spectrum of the existing analog data communication system.

US Patent:

7639806, Dec 29, 2009

Filed:

Mar 23, 2005

Appl. No.:

11/087365

Inventors:

Thomas E. Daniels - Boone IA, US
Mani Mina - Ames IA, US
Steve F. Russell - Ames IA, US

Assignee:

Iowa State University Research Foundation, Inc. - Ames IA

International Classification:

H04N 7/167
H04L 9/30
H04L 9/32
G06F 21/00
G06F 7/04
H04L 9/00
H04L 9/20
G11B 19/02
H04K 1/00
G08C 19/16
H03M 1/00

US Classification:

380203, 380247, 380201, 380202, 380200, 713168, 713182, 726 4, 726 5, 34087021, 341126, 369 4735

Abstract:

Methods and apparatus or systems for providing security based on innate characteristics of devices are disclosed. A method of providing security associated with communications from a digital device includes observing an analog signal associated with communications from the digital device, characterizing the digital device at least partially based on the analog signal, and providing a security feature at least partially based on the step of characterizing.

US Patent:

53274962, Jul 5, 1994

Filed:

Jun 30, 1993

Appl. No.:

8/085749

Inventors:

Steve F. Russell - Ames IA
John F. Doherty - Ames IA

Assignee:

Iowa State University Research Foundation, Inc. - Ames IA

International Classification:

H04K 102
H04L 2730
G10K 1116

US Classification:

380 6

Abstract:

A communication device, an apparatus, and a method for acoustic echo cancellation which makes use of a pseudonoise signal. An audio mixer adds the pseudonoise signal to an input signal received from another communication device to produce a first composite signal. An audio system converts the first composite signal to sound in an at least partially enclosed space. The at least partially enclosed space produces an acoustical echo in response. The audio system then converts the acoustical echo and other sounds in the at least partially enclosed space to a second composite signal. A signal processor cross-correlates the second composite signal with the pseudonoise signal to produce an estimate of the overall impulse response of the combined system formed by the at least partially enclosed space and the audio system. The processor then convolves the first composite signal with the impulse response estimate to produce an echo estimation signal. The echo estimation signal is an estimate of the component of the second composite signal which corresponds to the acoustical echo.

US Patent:

54619211, Oct 31, 1995

Filed:

Jul 13, 1993

Appl. No.:

8/091179

Inventors:

Emmanuel P. Papadakis - Ames IA
Steve F. Russell - Ames IA
Samuel J. Wormley - Ames IA

Assignee:

Iowa State University Research Foundation, Inc. - Ames IA

International Classification:

G01N 2910

US Classification:

73628

Abstract:

Techniques for providing an ultrasonic flaw detection system are disclosed. A continuous wave of wide-band direct-sequence spread-spectrum signals continuously drives one or more transmitting transducers, thereby flooding a test object with coded ultrasound. In operation, the ultrasonic testing system is capable of reliably and predictably transmitting a high degree of ultrasonic energy (power) to a test object. Code division multiplexing correlation techniques using a variably delayed replica of a selected segment of the DSSS signal are applied to the signals received by the receiving transducers to generate a signature representing the signal returned from all reflectors within the test object.

US Patent:

RE355747, Jul 29, 1997

Filed:

May 23, 1995

Appl. No.:

8/447686

Inventors:

Steve F. Russell - Ames IA
John F. Doherty - Ames IA

Assignee:

Iowa State University Research Foundation, Inc. - Ames IA

International Classification:

H04K 102
H04L 2730
G10K 1116

US Classification:

380 6

Abstract:

A communication device, an apparatus, and a method for acoustic echo cancellation which makes use of a pseudonoise signal. An audio mixer adds the pseudonoise signal to an input signal received from another communication device to produce a first composite signal. An audio system converts the first composite signal to sound in an at least partially enclosed space. The at least partially enclosed space produces an acoustical echo in response. The audio system then converts the acoustical echo and other sounds in the at least partially enclosed space to a second composite signal. A signal processor cross-correlates the second composite signal with the pseudonoise signal to produce an estimate of the overall impulse response of the combined system formed by the at least partially enclosed space and the audio system. The processor then convolves the first composite signal with the impulse response estimate to produce an echo estimation signal. The echo estimation signal is an estimate of the component of the second composite signal which corresponds to the acoustical echo.