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This paper presents a GTD-based 2D state-space algorithm for recovering shape and motion from range based signals. The GTD-based 2D state-space algorithm estimates the range and the range rate simultaneously in one operation using eigen decomposition, thus effectively solving the aliasing problem of the range tracks when the ranges of different scattering centers are overlapped. Compared with Fourier algorithm, the new method is not limited to identifying scatters at range gates, so it could estimate range and rage rate exactly. Meanwhile, three modified invariant-based shape and motion reconstruction algorithms for range data taken form unknown viewpoints are presented in this paper, including a novel sequential factorization method. Experiments using synthetic data illustrate that the state-space could effectively satisfy the demand of reconstruction algorithms for exact range data. [ABSTRACT FROM PUBLISHER]

We show a significant discrepancy between the range estimates and the actual performance of an ultrawideband wireless system based on the Wimedia standard. We also show this discrepancy to be linked to the combination of frequency selectivity of the ultrawideband channel and the low dynamic range available to ultrawideband receiver. We propose an alternative means of range estimation combining the statistics of frequency selective fading and the path-loss and we show that this algorithm provides significantly more accurate estimation. [ABSTRACT FROM PUBLISHER]

This work investigates three major phenomena of range estimation performance for a passive RFID system that transmits power-optimized waveforms (POWs). The shape of the POW, nonlinear charge pump reflections, and frequency-flat multipath environments are investigated. A maximum-likelihood (ML) range estimator analyzes the backscattered signal from a passive RFID tag that includes the POW as a carrier of tag data. The interferers in a linear-reflection system are multipath components and noise. However, the charge pump of the tag may also induce nonlinear distortion on the reflected POW. It is shown in this paper that each of these sources of interference may be accounted for in theoretical models of the uncertainty and bias of the ML estimator. [ABSTRACT FROM PUBLISHER]

A least squares estimation algorithm for the azimuth and elevation angles as well as range of a single near-field source impinging on a uniform circular array is proposed. By exploiting the centro-symmetric array configuration, two correlation functions are devised to obtain their closed-form estimates. It is shown that the proposed method gives comparable estimation performance with that of the conventional MUSIC scheme but the former is much computationally simple. [ABSTRACT FROM PUBLISHER]