Analysis of position-related information in measured UWB indoor channels

2013 IEEE Radar Conference (RadarCon13)

et al. 2013

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Abstract-High-accuracy localization remains a much desired but elusive feature for passive radio transponders as used in radio-frequency identification (RFID). We believe that the principle of cognitive radar can overcome the fundamental physical limitations hindering its implementation. We propose to jointly employ a narrowband radio to interrogate the transponders and an adaptive (ultra) wideband backscatter radio for the target tracking and for actuating, sensing, and learning the radio environment. This paper explores system model and key processing steps of such a cognitive secondary radar. At its core is a perception-action cycle, which consists of transmitter and receiver-side environment models for representing radio channel conditions and Bayesian trackers for the target states. Multipath is exploited to improve the robustness and to make optimum use of the radar's sensing capabilities. Feedback information is derived from the Cramér-Rao lower bound on the position error. Initial results are presented as a basic proof of principle.Index Terms-Ultra-wideband, Cramér-Rao lower bound, localization, multipath-assisted indoor positioning, channel modeling

Section: A Time-reversal Processing -Experimental Resultsmentioning

confidence: 99%

“…Firm insight is thus provided how to employ the CR for efficiently and robustly estimating the target locations. Evaluating (2), it has been found in [8], [15] that bandwidths of at least 1 GHz are needed to achieve satisfying positioning performance in dense indoor channels.…”

Section: −1 Pmentioning

confidence: 99%

Cognitive radar for the localization of RFID transponders in dense multipath environments

Witrisal

Leitinger

2013 IEEE Radar Conference (RadarCon13)

et al. 2013

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“…We compute the FIM J ψ of the auxiliary parameter vector ψ = [τ T (α R ) T (α I ) T ] T using (5) and (14). We closely follow the notation of [7].…”

Section: Computation Of the Fisher Information Matrix (Fim)mentioning

confidence: 99%

“…Recent experimental work reported in[14] gives related computational results based on an extensive channel measurement campaign.…”

mentioning

confidence: 99%

Performance bounds for multipath-assisted indoor navigation and tracking (MINT)

Witrisal

2012 IEEE International Conference on Communications (ICC)

2012

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The MINT (multipath-assisted indoor navigation and tracking) problem exploits the geometry of deterministic multipath components (MPCs) for robust indoor positioning in line-of-sight (LOS) and non-LOS situations. It assumes a known room layout and can thus easily make use of signals reflected by the walls, for instance. In this paper, the Cramér-Rao lower bound of the positioning error is derived for this problem. This requires a novel channel model, where diffuse multipath is modeled as a colored Gaussian process that influences the effective SNR of deterministic MPCs. The adverse effect of path overlap is demonstrated and discussed. Computational results show the three-fold importance of a large signal bandwidth. The bandwidth reciprocal (i.e. the pulse duration) multiplies the error standard deviation-a fundamental result well-known from AWGN channels. But it also multiplies the effective power of the interfering diffuse multipath and gives rise to additional path overlap. A minimum bandwidth of 1 GHz seems appropriate and sufficient.

“…Deep understanding of its channel characteristics is crucial for tasks, such as indoor localization and tracking [1], [2]. For UWB system, the channel characteristics vary significantly within the entire bandwidth.…”

Section: Introductionmentioning

confidence: 99%

Calibration of indoor UWB sub-band divided ray tracing using multiobjective simulated annealing

Gan

2014 IEEE International Conference on Communications (ICC)

Mani

et al. 2014

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Abstract-Sub-band divided ray tracing (RT) has been widely used to reproduce as reliably as possible the ultra-wideband (UWB) radio wave propagation channel in realistic indoor environments. However, its accuracy is strictly limited by the available description of the environment. Moreover, its computational complexity scales with the number of selected subbands and the number of propagation paths. In the present work, our RT tool considers not only deterministic propagation paths but also diffuse scattering components. Based on a low-complexity sub-band divided RT implementation, we propose a calibration method for indoor UWB sub-band divided RT. The method estimates the optimal material parameters, including the dielectric parameters and the scattering parameters, using channel measurements and multiobjective simulated annealing (MOSA). This calibration can improve the accuracy of sub-band divided RT in terms of the power delay profile (PDP) and the root mean square (RMS) delay spread for all test locations including those not considered by the calibration. A measurement campaign is used to verify the calibration technique.