Lockheed Martin Corporation

Koninklijke Philips Corporation N.v.

Proxim Wireless Corporation

John Terrence Reagan

Michael Levin

Henry C Kancler

Barry A Wealand

Katarina Van Heusen

Leon K Wood

Tsi-Pin Choong

Theodore J Mills

Lawrence K Lam

Alain M Chiodini

Theagenis John Abatzoglou

Anna Znamerovskaya

Homayoun Malek

A system and method for three-axis stabilization of focal plane data. The system and method include performing a two-dimensional vertical shear transformation and a two-dimensional horizontal shear transformation. The system and method further incorporate a SIMD computer architecture and an array of addressable processing elements that process the field-of-view for a target image received by a focal plane array of detector elements. Each processing element includes a calculation device that calculates the row and column address of virtual pixels for a virtual field-of-view. The system and method further include a plurality of memory modules configured to store data in a plurality of addressable storage locations by column and row, and each memory module is identified with a different processing element. A dedicated memory routing network for the processing elements and memory modules permits the exchange of information between processing elements and memory modules associated with each processing element.

Massively-parallel three-axis stabilization of focal plane data

Orthogonal frequency division multiplexing (OFDM) receiver embodiments of the invention provide data demodulator synchronization by finding the end of the short preamble in an IEEE-802.11a burst transmission. This method exploits the fact that there are certain symmetries in the long-preamble that can be used to determine synchronization. The long-preamble sequence is composed of a guard interval (GI) and two long-preamble symbols; the GI is the last 32 samples of the long-preamble symbol. The 32sample of the long-preamble acts as a 'pilot' or 'anchor' sample in that the previous N and subsequent N samples are complex conjugates, or conjugate &#x201c;mirror&#x201d; vectors. Due to the periodicities of the long-preamble, this property repeats every 32 samples. No other samples in the long preamble exhibit this property. Coherent combining is used in one embodiment for robustness. Once this &#x201c;pilot&#x201d; or &#x201c;anchor&#x201d; sample is located, the end of the short-preamble is declared to have occurred 32 samples earlier, thus establishing a time reference.

OFDM data demodulators synchronization

A method of reducing sinusoidal artifact generation in a vocoder. In one embodiment, the present invention first receives a determined input energy threshold value. The input energy threshold value is the value below which it is believed that a suspected noise-inducing codebook excitation vector will be generated by the vocoder. Next, provided that an input signal is received having an energy value lower than the input energy threshold value, the present invention uses a codebook excitation vector selection process to prevent the suspected noise-inducing codebook excitation vector from being continuously generated. In one embodiment, the codebook excitation vector selection process is a randomization codebook excitation vector selection process. In so doing, the present embodiment prevents the creation of harmonics during zero or low-energy input periods.

Reducing artifact generation in a vocoder

A signal processing system and method capable of real-time implementation for extracting signal parameter information with high accuracy and resolution. Signals (101) are passed through a filter bank (102), downconverted and decimated. The superresolution technique of constrained total least squares (CTLS) is used to process the resulting samples to obtain frequency components and their amplitudes (106). CTLS may also be used to obtain decaying coefficients associated with each frequency components. If desired, the results of CTLS may be used to extend original data for higher resolution spectral analysis and output (109).

Real-time superresolution signal processing

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Santa Clara, CA, United States of America

John Terrence Reagan