George N Eberl

US Patent:

6487256, Nov 26, 2002

Filed:

Apr 12, 2001

Appl. No.:

09/834077

Inventors:

Brian William Kroeger - Sykesville MD
E. Glynn Walden - Marlton NJ
George Nicholas Eberl - Columbia MD

Assignee:

Ibiquity Digital Corporation - Columbia MD

International Classification:

H04L 512

US Classification:

375265

Abstract:

A method for AM in-band-on-channel (IBOC) digital audio broadcasting (DAB) uses a center channel signal in a central frequency band of an AM radio channel, the center channel signal is modulated by first and second versions of the program material to be transmitted. Sub-carriers in a upper and lower sidebands of the AM radio channel are modulated with addition digitally encoded portions of the program material. The upper sideband lies within a frequency band extending from about +5 k Hz to about +10 kHz from a center frequency of the radio channel and the lower sideband lying within a frequency band extending from about -5 k Hz to about -10 kHz from the center frequency of the radio channel. The center channel signal the upper and lower sideband sub-carriers are transmitted to receivers. In a hybrid IBOC DAB version, the center channel signal includes a carrier which is analog modulated by the first version of the program material and additional sub-carriers modulated by the second version of the program material, wherein the additional sub-carriers are transmitted at a power spectral density level that is less than the power spectral density of the analog modulated carrier.

US Patent:

62434241, Jun 5, 2001

Filed:

Mar 27, 1998

Appl. No.:

9/049217

Inventors:

Brian William Kroeger - Sykesville MD
E. Glynn Walden - Marlton NJ
George Nicholas Eberl - Columbia MD

Assignee:

iBiguity Digital Corporation - Columbia MD

International Classification:

H04L 512
H04B 168

US Classification:

375265

Abstract:

A method for AM in-band-on-channel (IBOC) digital audio broadcasting (DAB) uses a center channel signal in a central frequency band of an AM radio channel, the center channel signal is modulated by first and second versions of the program material to be transmitted. Sub-carriers in a upper and lower sidebands of the AM radio channel are modulated with addition digitally encoded portions of the program material. The upper sideband lies within a frequency band extending from about +5 k Hz to about +10 kHz from a center frequency of the radio channel and the lower sideband lying within a frequency band extending from about -5 k Hz to about -10 kHz from the center frequency of the radio channel. The center channel signal the upper and lower sideband sub-carriers are transmitted to receivers. In a hybrid IBOC DAB version, the center channel signal includes a carrier which is analog modulated by the first version of the program material and additional sub-carriers modulated by the second version of the program material, wherein the additional sub-carriers are transmitted at a power spectral density level that is less than the power spectral density of the analog modulated carrier.

US Patent:

58289577, Oct 27, 1998

Filed:

Mar 14, 1996

Appl. No.:

8/615937

Inventors:

Brian W. Kroeger - Sykesville MD
Gregory W. Seker - Columbia MD
Paul J. Peyla - Elkridge MD
George N. Eberl - Columbia MD
Denise M. Cammarata - Owings Mills MD

International Classification:

H04Q 700

US Classification:

455428

Abstract:

An improved satellite beam acquisition and crossover technique for finding an appropriate satellite beam by searching for and acquiring a strongest pilot channel, searching for signalling channels on the acquired strongest pilot channel and monitoring the acquired signalling channel. Beam acquisition of a continuous wave pilot as in the preferred embodiment is faster and more reliable than beam acquisition of a modulated channel. Moreover, the acquired pilot channel can be used to unambiguously precalibrate the frequency reference of the mobile terminal. Also, acquisition of the pilot ensures that the corresponding satellite beam is not blocked or shadowed immediately prior to searching for a signalling channel, which significantly improves the reliability while reducing the time required for the search process. Mitigation of fading and shadowing is provided by using fast attack, slow decay non-linear filtering.