This paper deals with the near-field source localization using a uniform circular array (UCA). The blind array calibration method is also applied to the source localization using UCA with mutual coupling between eleme...
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ISBN:
(纸本)9784885523267
This paper deals with the near-field source localization using a uniform circular array (UCA). The blind array calibration method is also applied to the source localization using UCA with mutual coupling between elements. The computer simulation shows the effectiveness of the calibration in the near-field source localization with UCA.
Spatial frequency estimation from a superposition of impinging waveforms in the presence of noise is important in many applications. While subspace-based methods offer high-resolution parameter estimation at a low com...
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ISBN:
(纸本)9798350344820;9798350344813
Spatial frequency estimation from a superposition of impinging waveforms in the presence of noise is important in many applications. While subspace-based methods offer high-resolution parameter estimation at a low computational cost, they heavily rely on precise arraycalibration with a synchronized clock, posing challenges for large distributed antenna arrays. In this study, we focus on direction-of-arrival (DoA) estimation within sparse partly calibrated rectangular arrays. These arrays consist of multiple perfectly calibrated subarrays with unknown phase-offsets among them. We present a gridless sparse formulation for DoA estimation leveraging the multiple shift-invariance properties in the partly calibrated array. Additionally, an efficient blindcalibration technique is proposed based on semidefinite relaxation to estimate the intersubarray phase-offsets accurately.
One of the main challenges for next generation automotive radars is the improvement of angular resolution to a sub-degree level. In this context, wide aperture automotive radars of 1m length or more and resolution clo...
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ISBN:
(纸本)9783944976341
One of the main challenges for next generation automotive radars is the improvement of angular resolution to a sub-degree level. In this context, wide aperture automotive radars of 1m length or more and resolution close to 0.1 degrees in azimuth and 0.5 degrees in elevation could be beneficial. To enable coherent processing of arrays with such large aperture, prior (i.e offline) and online calibration are necessary: channel imbalances (gains and phases) and three dimensional coordinates of transmit and receive elements need to be determined. We propose a calibration strategy based on alternating steps between the two subtasks of i) channel imbalance estimation with 'known' array positions, by applying a singular value decomposition to the resulting tensor calculus problem;and ii) antenna position estimation with 'known' channel imbalances, by numerically maximizing the Bayesian posterior probability;in both cases operating on range/Doppler snapshots of disjoint targets (with potentially unknown locations). Simulation studies based on the parameters of a MIMO 8x6 linear sparse array show promising results as long as the initial position errors do not exceed half a wavelength (2 mm), beyond which we observe strong effects of ambiguity. Experimental results with real measurements show that after calibration in laboratory conditions, our MIMO 8x6 demonstrator with 50cm aperture is able to resolve two targets at the same range with angular separation at least as close as 0.4 degrees.
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