3 research outputs found
Off-grid Multi-Source Passive Localization Using a Moving Array
A novel direct passive localization technique through a single moving array
is proposed in this paper using the sparse representation of the array
covariance matrix in spatial domain. The measurement is constructed by stacking
the vectorized version of all the array covariance matrices at different
observing positions. First, an on-grid compressive sensing (CS) based method is
developed, where the dictionary is composed of the steering vectors from the
searching grids to the observing positions. Convex optimization is applied to
solve the `1-norm minimization problem. Second, to get much finer target
positions, we develop an on-grid CS based method, where the
majorization-minimization technique replaces the atan-sum objective function in
each iteration by a quadratic convex function which can be easily minimized.
The objective function,atan-sum, is more similar to `0-norm, and more sparsity
encouraging than the log-sum function.This method also works more robustly at
conditions of low SNR, and fewer observing positions are needed than in the
traditional ones. The simulation experiments verify the promises of the
proposed algorithm.Comment: 24pages, 9 figure
Parametric Sparse Bayesian Dictionary Learning for Multiple Sources Localization with Propagation Parameters Uncertainty and Nonuniform Noise
Received signal strength (RSS) based source localization method is popular
due to its simplicity and low cost. However, this method is highly dependent on
the propagation model which is not easy to be captured in practice. Moreover,
most existing works only consider the single source and the identical
measurement noise scenario, while in practice multiple co-channel sources may
transmit simultaneously, and the measurement noise tends to be nonuniform. In
this paper, we study the multiple co-channel sources localization (MSL) problem
under unknown nonuniform noise, while jointly estimating the parametric
propagation model. Specifically, we model the MSL problem as being
parameterized by the unknown source locations and propagation parameters, and
then reformulate it as a joint parametric sparsifying dictionary learning
(PSDL) and sparse signal recovery (SSR) problem which is solved under the
framework of sparse Bayesian learning with iterative parametric dictionary
approximation. Furthermore, multiple snapshot measurements are utilized to
improve the localization accuracy, and the Cramer-Rao lower bound (CRLB) is
derived to analyze the theoretical estimation error bound. Comparing with the
state-of-the-art sparsity-based MSL algorithms as well as CRLB, extensive
simulations show the importance of jointly inferring the propagation
parameters,and highlight the effectiveness and superiority of the proposed
method.Comment: 12 pages, 9 figure
Application of Compressive Sensing Techniques in Distributed Sensor Networks: A Survey
In this survey paper, our goal is to discuss recent advances of compressive
sensing (CS) based solutions in wireless sensor networks (WSNs) including the
main ongoing/recent research efforts, challenges and research trends in this
area. In WSNs, CS based techniques are well motivated by not only the sparsity
prior observed in different forms but also by the requirement of efficient
in-network processing in terms of transmit power and communication bandwidth
even with nonsparse signals. In order to apply CS in a variety of WSN
applications efficiently, there are several factors to be considered beyond the
standard CS framework. We start the discussion with a brief introduction to the
theory of CS and then describe the motivational factors behind the potential
use of CS in WSN applications. Then, we identify three main areas along which
the standard CS framework is extended so that CS can be efficiently applied to
solve a variety of problems specific to WSNs. In particular, we emphasize on
the significance of extending the CS framework to (i). take communication
constraints into account while designing projection matrices and reconstruction
algorithms for signal reconstruction in centralized as well in decentralized
settings, (ii) solve a variety of inference problems such as detection,
classification and parameter estimation, with compressed data without signal
reconstruction and (iii) take practical communication aspects such as
measurement quantization, physical layer secrecy constraints, and imperfect
channel conditions into account. Finally, open research issues and challenges
are discussed in order to provide perspectives for future research directions