388 research outputs found
Position and Orientation Estimation through Millimeter Wave MIMO in 5G Systems
Millimeter wave signals and large antenna arrays are considered enabling
technologies for future 5G networks. While their benefits for achieving
high-data rate communications are well-known, their potential advantages for
accurate positioning are largely undiscovered. We derive the Cram\'{e}r-Rao
bound (CRB) on position and rotation angle estimation uncertainty from
millimeter wave signals from a single transmitter, in the presence of
scatterers. We also present a novel two-stage algorithm for position and
rotation angle estimation that attains the CRB for average to high
signal-to-noise ratio. The algorithm is based on multiple measurement vectors
matching pursuit for coarse estimation, followed by a refinement stage based on
the space-alternating generalized expectation maximization algorithm. We find
that accurate position and rotation angle estimation is possible using signals
from a single transmitter, in either line-of- sight, non-line-of-sight, or
obstructed-line-of-sight conditions.Comment: The manuscript has been revised, and increased from 27 to 31 pages.
Also, Fig.2, Fig. 10 and Table I are adde
A robust compressive sensing based technique for reconstruction of sparse radar scenes
Cataloged from PDF version of article.Pulse-Doppler radar has been successfully applied to surveillance and tracking of both moving and
stationary targets. For efficient processing of radar returns, delay–Doppler plane is discretized and FFT
techniques are employed to compute matched filter output on this discrete grid. However, for targets
whose delay–Doppler values do not coincide with the computation grid, the detection performance
degrades considerably. Especially for detecting strong and closely spaced targets this causes miss
detections and false alarms. This phenomena is known as the off-grid problem. Although compressive
sensing based techniques provide sparse and high resolution results at sub-Nyquist sampling rates,
straightforward application of these techniques is significantly more sensitive to the off-grid problem.
Here a novel parameter perturbation based sparse reconstruction technique is proposed for robust delay–
Doppler radar processing even under the off-grid case. Although the perturbation idea is general and can
be implemented in association with other greedy techniques, presently it is used within an orthogonal
matching pursuit (OMP) framework. In the proposed technique, the selected dictionary parameters are
perturbed towards directions to decrease the orthogonal residual norm. The obtained results show that
accurate and sparse reconstructions can be obtained for off-grid multi target cases. A new performance
metric based on Kullback–Leibler Divergence (KLD) is proposed to better characterize the error between
actual and reconstructed parameter spaces. Increased performance with lower reconstruction errors are
obtained for all the tested performance criteria for the proposed technique compared to conventional
OMP and 1 minimization techniques.
© 2013 Elsevier Inc. All rights reserve
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