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Fault injection has become the main approach to evaluate the dependability of a circuit with respect to soft errors. It can be applied early during the design process and refined along all design steps. However, the main limitation is the huge number of faults that should be injected when large circuits and/or complex workloads and complex error models are considered. This usually leads to practical...
This paper proposes a novel and simple indoor localization system based on sensors on a grid and on radio map approach. We analyze the impact of different system variables on the localization error: the number of beacons composing the grid, the training points considered during the construction of the radio map, the radio channel fluctuations, the presence of multiple objects to localize simultaneously...
The multihop relay wireless access system is expected to eliminate dead spots by expanding line-of-sight situations and to extend coverage at low cost. However, time-division duplex relay schemes that apportion the fixed length frame resources between the access and relay zones like the IEEE802.16J relay scheme suffer the problems of degraded system capacity and poor latency performance. This paper...
This paper proposes an optimal soft fusion scheme for cooperative spectrum sensing in cognitive radio (CR) network. Multiple cooperative secondary users (SUs) simply serve as relay nodes in the network to provide space diversity for spectrum sensing. An optimal soft fusion scheme of the relayed sensing observations is derived in Neyman-Pearson framework, on the basis of maximizing the deflection coefficient...
Coded Cooperation (CC) is a promising user cooperation scheme. In this paper, we propose a novel network- coding-based coded cooperation scheme. When a user decodes its partner's information correctly in the first frame, it transmits the combination of the partner's parity bits and its own parity bits through network coding in the second frame. This is distinct from the classical scheme, where the...
Fully exploiting the phase and magnitude information in received data is crucial to the detection of cognitive radio signals, and this is usually done in the time domain. In fact, the same set of information can also be exploited in the frequency domain in the form of power spectrum. The most appealing one is the multitaper spectrum (MTS) estimator, which enjoys a high estimation accuracy and relatively...
Based on matrix multiplication secret sharing method, a multi-secret images sharing scheme is presented. In our scheme, participants only need to pool their pseudo-shadow instead of disclosing his secret share when recovering secret images. That is to say, each participant can share many secret images with others by holding only one secret share. Unlike other known image sharing scheme, it doesnpsilat...
In this contribution, an analysis procedure is proposed for time-varying analysis and synthesis of speech based on lattice filters. The estimation is performed by an iterative inverse filtering approach exploiting analytical suboptimal solutions. Starting from an initial configuration of coefficients, the procedure estimates a continuous piece-wise linear trajectory in terms of reflection coefficients...
It has been known for a while that l1-norm relaxation can in certain cases solve an under-determined system of linear equations. Recently, [5, 10] proved (in a large dimensional and statistical context) that if the number of equations (measurements in the compressed sensing terminology) in the system is proportional to the length of the unknown vector then there is a sparsity (number of non-zero elements...
Two new theorems show how deliberately adding quantizer noise can improve statistical signal detection in array-based nonlinear correlation detection even in the case of infinite-variance alpha-stable channel noise. The first theorem gives a necessary and sufficient condition for such quantizer noise to increase the detection probability for a fixed false-alarm probability. The second theorem shows...
In this paper the effects of receiver nonlinearities are examined for clipping channels. The objective of this work is to determine the optimal receiver functions for additive noise clipping channels. In this case the optimal receiver function will be the one that maximizes the signal-to-noise-plus-distortion ratio (SNDR) between the transmitted and received variables. To solve the problem we utilize...
We design distributed and quantized average consensus algorithms on arbitrary connected networks. By construction, quantized algorithms cannot produce a real, analog average. Instead, our algorithm reaches consensus on the quantized interval that contains the average. We prove that this consensus in reached in finite time almost surely. As a by-product of this convergence result, we show that the...
Near-field source localization problem by a passive antenna array makes the assumption that the time-varying sources are located near the antenna. In this situation, the far-field assumption (planar wavefront) is no longer valid and we have to consider a more complicated model parameterized by the bearing (as in the far-field case) and by the distance, named range, between the source and a reference...
This paper presents a novel approach for computing both the minimum-phase filter and the associated all-pass filter in a computationally efficient way using fast QL-factorization. A desirable property of this approach is that the complexity is independent of the size of the matrix being QL-factorized. Instead, the complexity scales with the required precision of the filters as well as the filter length.
The restricted isometry property (RIP) introduced by Candes and Tao is a fundamental property in compressed sensing theory. It says that if a sampling matrix satisfies the RIP of certain order proportional to the sparsity of the signal, then the original signal can be reconstructed even if the sampling matrix provides a sample vector which is much smaller in size than the original signal. This short...
In this paper, we propose a novel radius control strategy for sphere decoding referred to as inter search radius control that provides further improvement of the computational complexity with minimal extra cost and negligible performance penalty. The proposed method focuses on the sphere radius control strategy when a candidate lattice point is found. For this purpose, the dynamic radius update strategy...
The problem of designing simple and energy-efficient nonlinear distributed source-channel codes is considered. By demonstrating similarities between this problem and the problem of bandwidth expansion, a structure for source-channel codes is presented and analyzed. Based on this analysis an understanding about desirable properties for such a system is gained and used to produce an explicit source-channel...
Achieving low energy consumption is one of the main challenges for wireless video transmission on battery-limited devices. Moreover, the bandwidth is scarce and must be shared efficiently among users. The focus in this paper is on the timely delivery of multiple delay-sensitive video flows over a distributed access wireless LAN with minimal energy cost. This is done taking into consideration the Enhanced...
We propose a multi-task learning (MTL) framework for non-linear classification, based on an infinite set of local experts in feature space. The usage of local experts enables sharing at the expert-level, encouraging the borrowing of information even if tasks are similar only in subregions of feature space. A kernel stick-breaking process (KSBP) prior is imposed on the underlying distribution of class...
In the recent years, denoising based on the spatially adaptive algorithms that employ anisotropic adaption have been developed. These methods are able to match to the local statistics, preserve the edges and truly remove the noise from the texture of the images. On the other hand, a huge proportion of image enhancement methods are implemented in the sparse domains (e.g., wavelets, curvelets, contourlets...
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