Mark R Dunham

US Patent:

59109050, Jun 8, 1999

Filed:

Nov 8, 1996

Appl. No.:

8/744435

Inventors:

Shie Qian - Austin TX
Mark E. Dunham - Los Alamos NM

Assignee:

National Instruments Corporation - Austin TX

International Classification:

G06F 1710

US Classification:

36472408

Abstract:

A system and method for detecting the presence of dispersed broadband signals in real time. The present invention utilizes a bank of matched filters for detecting the received dispersed broadband signals. Each matched filter uses a respective robust time template that has been designed to approximate the dispersed broadband signals of interest, and each time template varies across a spectrum of possible dispersed broadband signal time templates. The received dispersed broadband signal x(t) is received by each of the matched filters, and if one or more matches occurs, then the received data is determined to have signal data of interest. This signal data can then be analyzed and/or transmitted to Earth for analysis, as desired. The system and method of the present invention will prove extremely useful in many fields, including satellite communications, plasma physics, and interstellar research. The varying time templates used in the bank of matched filters are determined as follows.

US Patent:

55746390, Nov 12, 1996

Filed:

Oct 12, 1994

Appl. No.:

8/322053

Inventors:

Shie Qian - Austin TX
Mark E. Dunham - Los Alamos NM

Assignee:

National Instruments Corporation - Austin TX

International Classification:

G06F 1710

US Classification:

36472401

Abstract:

A system and method for constructing a bank of filters which detect the presence of signals whose frequency content varies with time. The present invention includes a novel system and method for developing one or more time templates designed to match the received signals of interest and the bank of matched filters use the one or more time templates to detect the received signals. Each matched filter compares the received signal x(t) with a respective, unique time template that has been designed to approximate a form of the signals of interest. The robust time domain template is assumed to be of the order of w(t)=A(t)cos{2. pi. phi. (t)} and the present invention uses the trajectory of a joint time-frequency representation of x(t) as an approximation of the instantaneous frequency function {. phi. '(t). First, numerous data samples of the received signal x(t) are collected. A joint time frequency representation is then applied to represent the signal, preferably using the time frequency distribution series (also known as the Gabor spectrogram).