Joseph C Whited

US Patent:

6968021, Nov 22, 2005

Filed:

Sep 24, 2001

Appl. No.:

09/961666

Inventors:

Steven L. White - Cedar Rapids IA, US
Joseph C. Whited - Marion IA, US
Thomas L. Tapp - Cedar Rapids IA, US
Rodney L. Mickelson - Cedar Rapids IA, US

Assignee:

Rockwell Collins - Cedar Rapids IA

International Classification:

H03D001/00

US Classification:

375340, 375343, 375371, 375324, 375265, 714799

Abstract:

A bandwidth efficient advanced modulation waveform modem using concatenated iterative turbo coding and continuous phase modulation is disclosed. A demodulator in the modem has a turbo decoder and a decision feedback carrier and time tracking algorithm to track a carrier and adjust timing. The decision feedback carrier and time tracking algorithm may use an APP decoder as a decision device to provide symbol decisions at a high error rate and low latency for a coded input data stream. A symbol phase estimator produces a symbol phase error estimate from the symbol decisions. An erasure decision function decides which symbol decisions are correct and which symbol decisions are erasures. A carrier tracking function receives the symbol phase error estimates when the symbol decisions are correct and receives erasure inputs when the symbol decisions are erasures to maintain carrier tracking.

US Patent:

6934327, Aug 23, 2005

Filed:

Apr 23, 2001

Appl. No.:

09/840613

Inventors:

Joseph C. Whited - Marion IA, US
Steven L. White - Cedar Rapids IA, US

Assignee:

Rockwell Collins - Cedar Rapids IA

International Classification:

H04B017/00
H04B003/46
H04Q001/20

US Classification:

375225

Abstract:

Acquisition of a waveform such as a continuous-phase modulation (CPM) waveform is described. In one embodiment of the invention, the invention is directed to a method and apparatus for acquiring a waveform as defined by MIL-STD-188-181B including the preamble of such a waveform at a performance level defined by the standard. The present invention provides solutions to at least four primary issues presented in acquiring a CPM waveform such as the MIL-STD-188-181B compliant waveform. These primary problems include searching for the preamble, determination of the symbol rate, determination of an initial carrier frequency error (Doppler), determination of an initial carrier phase, and determination of the start-of-message to establish an absolute time marker within the waveform.