51 research outputs found
IRCI Free Range Reconstruction for SAR Imaging with Arbitrary Length OFDM Pulse
Our previously proposed OFDM with sufficient cyclic prefix (CP) synthetic
aperture radar (SAR) imaging algorithm is inter-range-cell interference (IRCI)
free and achieves ideally zero range sidelobes for range reconstruction. In
this OFDM SAR imaging algorithm, the minimum required CP length is almost equal
to the number of range cells in a swath, while the number of subcarriers of an
OFDM signal needs to be more than the CP length. This makes the length of a
transmitted OFDM sequence at least almost twice of the number of range cells in
a swath and for a wide swath imaging, the transmitted OFDM pulse length becomes
long, which may cause problems in some radar applications. In this paper, we
propose a CP based OFDM SAR imaging with arbitrary pulse length, which has IRCI
free range reconstruction and its pulse length is independent of a swath width.
We then present a novel design method for our proposed arbitrary length OFDM
pulses. Simulation results are presented to illustrate the performances of the
OFDM pulse design and the arbitrary pulse length CP based OFDM SAR imaging.Comment: 29 pages, 10 figures, regular pape
Space-Time Transmit-Receive Design for Colocated MIMO Radar
This chapter deals with the design of multiple input multiple-output (MIMO) radar space-time transmit code (STTC) and space-time receive filter (STRF) to enhance moving targets detection in the presence of signal-dependent interferences, where we assume that some knowledge of target and clutter statistics are available for MIMO radar system according to a cognitive paradigm by using a site-specific (possible dynamic) environment database. Thus, an iterative sequential optimization algorithm with ensuring the convergence is proposed to maximize the signal to interference plus noise ratio (SINR) under the similarity and constant modulus constraints on the probing waveform. In particular, each iteration of the proposed algorithm requires to solve the hidden convex problems. The computational complexity is linear with the number of iterations and polynomial with the sizes of the STTW and the STRF. Finally, the gain and the computation time of the proposed algorithm also compared with the available methods are evaluated
Robust Distributed Fusion with Labeled Random Finite Sets
This paper considers the problem of the distributed fusion of multi-object
posteriors in the labeled random finite set filtering framework, using
Generalized Covariance Intersection (GCI) method. Our analysis shows that GCI
fusion with labeled multi-object densities strongly relies on label
consistencies between local multi-object posteriors at different sensor nodes,
and hence suffers from a severe performance degradation when perfect label
consistencies are violated. Moreover, we mathematically analyze this phenomenon
from the perspective of Principle of Minimum Discrimination Information and the
so called yes-object probability. Inspired by the analysis, we propose a novel
and general solution for the distributed fusion with labeled multi-object
densities that is robust to label inconsistencies between sensors.
Specifically, the labeled multi-object posteriors are firstly marginalized to
their unlabeled posteriors which are then fused using GCI method. We also
introduce a principled method to construct the labeled fused density and
produce tracks formally. Based on the developed theoretical framework, we
present tractable algorithms for the family of generalized labeled
multi-Bernoulli (GLMB) filters including -GLMB, marginalized
-GLMB and labeled multi-Bernoulli filters. The robustness and
efficiency of the proposed distributed fusion algorithm are demonstrated in
challenging tracking scenarios via numerical experiments.Comment: 17pages, 23 figure
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