Communications: directive radio wave systems and devices (e.g. – Directive – Including a steerable array
Reexamination Certificate
2006-06-06
2006-06-06
Tarcza, Thomas H. (Department: 3662)
Communications: directive radio wave systems and devices (e.g.,
Directive
Including a steerable array
Reexamination Certificate
active
07057555
ABSTRACT:
A directional antenna system is disclosed in which a plurality of RF nodes are provided for cooperatively forming a directional antenna array for transmitting and receiving wireless signals between a wireless client at a predetermined position in space. One or more network interface assemblies are provided for exchanging signals between the plurality of RF nodes and a network. Preferably, the plurality of RF nodes are distributed in space with respect to each other and the network interface assembly. The network interface includes a beamformer for applying a plurality of antenna weighting factors to the respective RF nodes, for introducing phase differences in the respective transmitted and received wireless signals that produce a directional steering vector for the wireless signals. In one embodiment of the invention, a processing arrangement is provided for deriving an array manifold, which includes a respective plurality of antenna weighting factors corresponding respectively to distances between each of the plurality of RF nodes, for producing the directional steering vector for the wireless signals. In another embodiment of the invention, a subspace beamforming arrangement is provided for building a covariance matrix from sampled values of a wireless client signal at each RF node, and deriving dominant eigenvectors corresponding to each RF node. The dominant eigenvectors are used as the respective antenna weighting factors for producing the directional steering vectors for the wireless signals.
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Cisco Technology Inc.
Mull Fred H
Tarcza Thomas H.
Tucker Ellis & West LLP
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