Abstract: A method and a system of determining a surface location defining an interface between an object to image and an antenna is provided. The method uses geometric principles and the fact that an impedance mismatch at the interface results in significant reflection. A propagation time from the surface to each antenna of a plurality of antennas is estimated. The propagation time locates the surface on a circle centered at each antenna and having a radius calculated using the propagation time. A tangent line connects the intersection of adjacent circles with the surface. The surface is estimated to be located at the tangent point where the circle and the shared tangent line between adjacent antennas intersect. Multiple tangent points may be averaged for each interior antenna. A curve is fit to the set of tangent points to provide an estimate of the surface location.

Abstract: A method and system is described for more optimally managing the usage of a wideband space-time multipath channel. The wideband space-time multipath channel is decomposed into a plurality of orthogonal sub-channels, where the orthogonal sub-channels having the best signaling characteristics are used for transmitting one or more signal streams. For purposes of decomposing the wideband space-time multipath channel into a plurality of orthogonal sub-channels, channel estimates are determined for each signal propagation path. A closed-form singular value decomposition of the channel corresponding to each receive antenna before coherent combining is utilized to obtain an orthogonal decomposition of the overall effective space-time channel after coherent combining. By using the overall effective space-time channel after coherent combining rather than before coherent combining, the complexity and correspondingly the resources required for obtaining the orthogonal sub-channels is significantly reduced.

Abstract: A method and system is described for more optimally managing the usage of a wideband space-time multipath channel. The wideband space-time multipath channel is decomposed into a plurality of orthogonal sub-channels, where the orthogonal sub-channels having the best signaling characteristics are used for transmitting one or more signal streams. For purposes of decomposing the wideband space-time multipath channel into a plurality of orthogonal sub-channels, channel estimates are determined for each signal propagation path. A closed-form singular value decomposition of the channel corresponding to each receive antenna before coherent combining is utilized to obtain an orthogonal decomposition of the overall effective space-time channel after coherent combining. By using the overall effective space-time channel after coherent combining rather than before coherent combining, the complexity and correspondingly the resources required for obtaining the orthogonal sub-channels is significantly reduced.