Performance Bounds for Sparsity Pattern Recovery with Quantized Noisy Random Projections

In this paper, we study the performance limits of recovering the support of a sparse signal based on quantized noisy random projections. Although the problem of support recovery of sparse signals with real valued noisy projections with different types of projection matrices has been addressed by several authors in the recent literature, very few attempts have been made for the same problem with quantized compressive measurements. In this paper, we derive performance limits of support recovery of sparse signals when the quantized noisy corrupted compressive measurements are sent to the decoder over additive white Gaussian noise channels. The sufficient conditions which ensure the perfect recovery of sparsity pattern of a sparse signal from coarsely quantized noisy random projections are derived when the maximum likelihood decoder is used. More specifically, we find the relationships among the parameters, namely the signal dimension N, the sparsity index K, the number of noisy projections M, the number of quantization levels L, and measurement signal-to-noise ratio which ensure the asymptotic reliable recovery of the support of sparse signals when the entries of the measurement matrix are drawn from a Gaussian ensemble

Exact Performance Analysis of the Oracle Receiver for Compressed Sensing Reconstruction

A sparse or compressible signal can be recovered from a certain number of noisy random projections, smaller than what dictated by classic Shannon/Nyquist theory. In this paper, we derive the closed-form expression of the mean square error performance of the oracle receiver, knowing the sparsity pattern of the signal. With respect to existing bounds, our result is exact and does not depend on a particular realization of the sensing matrix. Moreover, our result holds irrespective of whether the noise affecting the measurements is white or correlated. Numerical results show a perfect match between equations and simulations, confirming the validity of the result.Comment: To be published in ICASSP 2014 proceeding

Compressive sensor networks : fundamental limits and algorithms

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 85-92).Compressed sensing is a non-adaptive compression method that takes advantage of natural sparsity at the input and is fast gaining relevance to both researchers and engineers for its universality and applicability. First developed by Candis et al., the subject has seen a surge of high-quality results both in its theory and applications. This thesis extends compressed sensing ideas to sensor networks and other bandwidth-constrained communication systems. In particular, we explore the limits of performance of compressive sensor networks in relation to fundamental operations such as quantization and parameter estimation. Since compressed sensing is originally formulated as a real-valued problem, quantization of the measurements is a very natural extension. Although several researchers have proposed modified reconstruction methods that mitigate quantization noise for a fixed quantizer, the optimal design of such quantizers is still unknown. We propose to find the optimal quantizer in terms of minimizing quantization error by using recent results in functional scalar quantization. The best quantizer in this case is not the optimal design for the measurements themselves but rather is reweighted by a factor we call the sensitivity. Numerical results demonstrate a constant-factor improvement in the fixed-rate case. Parameter estimation is an important goal of many sensing systems since users often care about some function of the data rather than the data itself.(cont.) Thus, it is of interest to see how efficiently nodes using compressed sensing can estimate a parameter, and if the measurements scalings can be less restrictive than the bounds in the literature. We explore this problem for time difference and angle of arrival, two common methods for source geolocation. We first derive Cramer-Rao lower bounds for both parameters and show that a practical block-OMP estimator can be relatively efficient for signal reconstruction. However, there is a large gap between theory and practice for time difference or angle of arrival estimation, which demonstrates the CRB to be an optimistic lower bound for nonlinear estimation. We also find scaling laws 'for time difference estimation in the discrete case. This is strongly related to partial support recovery, and we derive some new sufficient conditions that show a very simple reconstruction algorithm can achieve substantially better scaling than full support recovery suggests is possible.by John Zheng Sun.S.M