Mark John Takatz

US Patent:

7483500, Jan 27, 2009

Filed:

Apr 6, 2006

Appl. No.:

11/399224

Inventors:

Mark J. Takatz - Melbourne FL, US
Stefan Haenggi - Melbourne Beach FL, US

Assignee:

IPR Licensing, Inc. - Wilmington DE

International Classification:

H04L 27/08

US Classification:

375345, 375316, 455136, 455138, 4552341, 4552391, 4552451, 4552471

Abstract:

An Automatic Gain Control (AGC) circuit as used in a digital receiver that utilizes a main loop filter that is of a relatively wide bandwidth. A pre-filter, wideband variance is determined from the input digital signal, and a post-filter, narrowband variance is also determined. The wideband and narrowband variances are then compared to determine if the wideband signal power indicates a variance level that is too great to permit normal loop operation. By reapplying this difference in the power levels to the filter output as needed, such as by a scaling operation, the loss in dynamic range is effectively recovered. In a preferred embodiment, an adjustable gain input amplifier feeds an intermediate frequency (IF) signal to an analog-to-digital converter (ADC). The digitized IF signal is then down-converted to a baseband frequency and subjected to digital filtering. A narrowband sample variance (P) of the digitally filtered (narrowband) data is then determined.

US Patent:

7653159, Jan 26, 2010

Filed:

Jan 27, 2009

Appl. No.:

12/360464

Inventors:

Mark J. Takatz - Melbourne FL, US
Stefan Haenggi - Melbourne Beach FL, US

Assignee:

IPR Licensing, Inc. - Wilmington DE

International Classification:

H04L 27/08

US Classification:

375345, 375316, 4552341, 4552321, 4552001

Abstract:

An Automatic Gain Control (AGC) circuit as used in a digital receiver that utilizes a main loop filter that is of a relatively wide bandwidth. A pre-filter, wideband variance is determined from the input digital signal, and a post-filter, narrowband variance is also determined. The wideband and narrowband variances are then compared to determine if the wideband signal power indicates a variance level that is too great to permit normal loop operation. By reapplying this difference in the power levels to the filter output as needed, such as by a scaling operation, the loss in dynamic range is effectively recovered. In a preferred embodiment, an adjustable gain input amplifier feeds an intermediate frequency (IF) signal to an analog-to-digital converter (ADC). The digitized IF signal is then down-converted to a baseband frequency and subjected to digital filtering. A narrowband sample variance (P) of the digitally filtered (narrowband) data is then determined.

US Patent:

20020163979, Nov 7, 2002

Filed:

May 1, 2001

Appl. No.:

09/847056

Inventors:

Mark Takatz - Melbourne FL, US
Alton Keel - Hellam PA, US
Stefan Haenggi - Melbourne Beach FL, US

Assignee:

Tantivy Communictions, Inc. - Melbourne FL

International Classification:

H04L027/08

US Classification:

375/345000, 455/234100

Abstract:

An Automatic Gain Control (AGC) circuit as used in a digital receiver that utilizes a main loop filter that is of a relatively wide bandwidth. A pre-filter, wideband variance is determined from the input digital signal, and a post-filter, narrowband variance is also determined. The wideband and narrowband variances are then compared to determine if the wideband signal power indicates a variance level that is too great to permit normal loop operation. By reapplying this difference in the power levels to the filter output as needed, such as by a scaling operation, the loss in dynamic range is effectively recovered. In a preferred embodiment, an adjustable gain input amplifier feeds an intermediate frequency (IF) signal to an analog-to-digital converter (ADC). The digitized IF signal is then down-converted to a baseband frequency and subjected to digital filtering. A narrowband sample variance (P) of the digitally filtered (narrowband) data is then determined. A wideband sample variance (P) is also taken from the raw ADC output data over the same period as the time period used for P. In the presence of out-of-band signal components, Pwill be quite different from P. This difference indicates a desired proportional difference in a control voltage or a gain backoff amount.

Address:

4577 Gold Medal Pt APT 350, Colorado Springs, CO 80923

VIN:

5N1AN08W57C533545

Make:

NISS

Model:

XTER

Year:

2007