Bae Systems Information and Electronic Systems Integration Inc.

Frantorf Investments Gmbh, LLC

Michael J Kotrlik

John M Smith

Diane Grieselhuber Mills

Edward C Real

Kari M Karwedsky

Wojciech J Krawiec

A real-time implementation of a subspace tracker is disclosed. Efficient architecture addresses the unique computational elements of the Fast Approximate Subspace Tracking (FAST) algorithm. Each of these computational elements can scale with the rank and size of the subspace. One embodiment of architecture described is implemented in digital hardware that performs variable rank subspace tracking using the FAST algorithm. In particular, the FAST algorithm is effectively implemented by a few processing elements, coupled with an efficient Singular Vector Decomposition (SVD), and the realization/availability of high density programmable logic devices. The architecture enables the ability to track the possibly changing dimension of the signal subspace.

Scalable architecture for subspace signal tracking

A two-plane rotation (TPR) approach to Gaussian elimination (Jacobi) is used for computational efficiency in determining rotation parameters. A rotation processor is constructed using the TPR approach to perform singular value decomposition (SVD) on two by two matrices yielding both eigenvalues and left and right eigenvectors. The rotation processor can then be replicated and interconnected to achieve higher dimensioned matrices. For higher dimensional matrices, the rotation processors on the diagonal solve the 2&#xd7;2 rotation angles, broadcast the results to off-diagonal processors, whereby all processors perform matrix rotations in parallel.

Scalable 2&#xd7;2 rotation processor for singular value decomposition

Interference cancellation techniques for use in a wireless multicarrier communications system where signals from multiple wireless networks might be present and interfering with the detection and demodulation processes are disclosed. Interference cancellation is applied to the interfering network before removing same-system interference. By removing the contribution of all interfering systems' from a receiver's aggregate signal, the receiver is capable of detection and demodulation. Performance can be further improved by including an additional level of interference cancellation within the system of interest to separate the individual user of interest.

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Nashua, NH, United States of America

Michael J Kotrlik