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This page shows you the most recent publications within this specialty of the MedWorm directory. This is page number 13.

Corrections to “Vector Cross-Product Direction-Finding’ With an Electromagnetic Vector-Sensor of Six Orthogonally Oriented But Spatially Noncollocating Dipoles/Loops”
(Source: IEEE Transactions on Signal Processing)
Source: IEEE Transactions on Signal Processing - January 24, 2014 Category: Biomedical Engineering Source Type: research

Table of Contents
(Source: IEEE Transactions on Signal Processing)
Source: IEEE Transactions on Signal Processing - January 24, 2014 Category: Biomedical Engineering Source Type: research

Learning Overcomplete Dictionaries Based on Atom-by-Atom Updating
A dictionary learning algorithm learns a set of atoms from some training signals in such a way that each signal can be approximated as a linear combination of only a few atoms. Most dictionary learning algorithms use a two-stage iterative procedure. The first stage is to sparsely approximate the training signals over the current dictionary. The second stage is the update of the dictionary. In this paper we develop some atom-by-atom dictionary learning algorithms, which update the atoms sequentially. Specifically, we propose an efficient alternative to the well-known K-SVD algorithm, and show by various experiments that the...
Source: IEEE Transactions on Signal Processing - January 24, 2014 Category: Biomedical Engineering Source Type: research

Maximum Likelihood Laplacian Correlation Channel Estimation in Layered Wyner-Ziv Coding
The distributed source coding theory teaches that efficient compression can be achieved by exploiting the correlation between encoded sources at the decoder only. A critical issue in this coding paradigm is how to accurately estimate the correlation statistics at the decoder. This paper proposes a novel correlation channel estimation method designed for generic layered Wyner-Ziv (WZ) coding. Driven by real-life applications, i.e., video coding, the correlation noise is assumed to be memoryless zero-mean Laplacian with a block-stationary behavior. Unlike existing methods, the proposed technique derives a novel maximum likel...
Source: IEEE Transactions on Signal Processing - January 24, 2014 Category: Biomedical Engineering Source Type: research

Clustering on Multi-Layer Graphs via Subspace Analysis on Grassmann Manifolds
Relationships between entities in datasets are often of multiple nature, like geographical distance, social relationships, or common interests among people in a social network, for example. This information can naturally be modeled by a set of weighted and undirected graphs that form a global multi-layer graph, where the common vertex set represents the entities and the edges on different layers capture the similarities of the entities in term of the different modalities. In this paper, we address the problem of analyzing multi-layer graphs and propose methods for clustering the vertices by efficiently merging the informat...
Source: IEEE Transactions on Signal Processing - January 24, 2014 Category: Biomedical Engineering Source Type: research

Decision Directed Estimation of Threshold Voltage Distribution in NAND Flash Memory
High-density NAND flash memory suffers from the data retention problem because even small charge leakage incurs a large threshold voltage shift as the transistor size shrinks. In this paper, we develop a decision directed estimation (DDE) algorithm to know the effects of charge leakage in NAND flash memory using the error pattern of the accessed data. While the conventional sensing directed estimation (SDE) method demands extra memory sensing to know the signal distribution, the proposed DDE algorithm induces no sensing overheads. The proposed algorithm approximates the threshold voltage distribution as a Gaussian mixture ...
Source: IEEE Transactions on Signal Processing - January 24, 2014 Category: Biomedical Engineering Source Type: research

Performance Analysis of a Power Limited Spectrum Sharing System With TAS/MRC
Capacity of the cognitive radio network degrades due to the interference constraint from the primary network. The secondary network capacity can be enhanced in a cost effective way by means of spatial diversity, that can be achieved by adding multiple antennas on the secondary network terminals and performing antenna selection. In this paper, the performance of a multiple-input multiple-output (MIMO) secondary link with transmit antenna selection (TAS) at the transmitter and maximum ratio combining (MRC) at the receiver is analyzed. A peak transmit power constraint at the secondary transmitter is considered in addition to ...
Source: IEEE Transactions on Signal Processing - January 24, 2014 Category: Biomedical Engineering Source Type: research

On Using the Relative Configuration to Explore Cooperative Localization
Cooperative localization differs from conventional localizations in using the measurements between the unknown nodes, which provide the relative location information of the nodes. This paper investigates cooperative localization by adopting the concept of relative configuration that describes the “shape” of the node network, without considering its absolute location, orientation, and/or scaling. Since the relative configuration is a non-Euclidean object, we introduce the Procrustes coordinates as a coordinate representation, suggest using the relative error as a coordinate independent error metric, and then d...
Source: IEEE Transactions on Signal Processing - January 24, 2014 Category: Biomedical Engineering Source Type: research

Recovery of Low-Rank Matrices Under Affine Constraints via a Smoothed Rank Function
In this paper, the problem of matrix rank minimization under affine constraints is addressed. The state-of-the-art algorithms can recover matrices with a rank much less than what is sufficient for the uniqueness of the solution of this optimization problem. We propose an algorithm based on a smooth approximation of the rank function, which practically improves recovery limits on the rank of the solution. This approximation leads to a non-convex program; thus, to avoid getting trapped in local solutions, we use the following scheme. Initially, a rough approximation of the rank function subject to the affine constraints is o...
Source: IEEE Transactions on Signal Processing - January 24, 2014 Category: Biomedical Engineering Source Type: research

CWRU researchers find epileptic activity spreads in new way
(Case Western Reserve University) Researchers in the biomedical engineering department at Case Western Reserve University have found that epileptic activity can spread through a part of the brain in a new way, suggesting a possible novel target for seizure-blocking medicines. Evidence from a series of experiments and computer modeling strongly suggests individual cells in a part of the brain, known as the hippocampus, use a small electrical field to stimulate and synchronize neighboring cells, spreading the activity layer by layer. (Source: EurekAlert! - Biology)
Source: EurekAlert! - Biology - January 24, 2014 Category: Biology Source Type: news

Color edges extraction using statistical features and automatic threshold technique: application to the breast cancer cells
Conclusions: Computer simulations highlight that the proposed method substantially enhances the segmented image with smaller error rates better than other existing algorithms under the same settings (patterns and parameters). Moreover, it provides high classification accuracy, reaching the rate of 97.94%. Additionally, the segmentation method may be extended to other medical imaging types having similar properties. (Source: BioMedical Engineering OnLine)
Source: BioMedical Engineering OnLine - January 23, 2014 Category: Biomedical Engineering Authors: Salim Ben ChaabaneFarhat Fnaiech Source Type: research

Special Issues: Representing Diversity in Education: Student identities in contexts of learning and instruction & Classroom-Based Talk
International Journal of Education Research, Volume 63, pages 1-140 (2014) Edited by (Source: Elsevier Updates: Engineering)
Source: Elsevier Updates: Engineering - January 22, 2014 Category: Biomedical Engineering Source Type: news

Effects of ultrasonic and microwave pretreatments on lipid extraction of microalgae.
Abstract The extraction of lipids from microalgal cells using ultrasonic and microwave pretreatments is mechanistically evaluated based on the distribution of cell fragments, the lipid content analysis, the scanning electron microscopic (SEM) observation of ruptured microalgal cells, and the analysis of fatty acids. The results indicate that microwave pretreatment extracts lipids more rapidly and efficiently as compared to ultrasonic pretreatment. The rupture of cells in the microwave process is due to the tremendous pressure caused by the rapid heating of the moisture inside the microalgal cells, whereas in the ul...
Source: Bioprocess and Biosystems Engineering - January 22, 2014 Category: Biomedical Engineering Authors: Ma YA, Cheng YM, Huang JW, Jen JF, Huang YS, Yu CC Tags: Bioprocess Biosyst Eng Source Type: research

A Nanoengineered Embolic Agent for Precise Radiofrequency Ablation.
In conclusion, the combination of RFA plus marsembol + MWCNT embolization delineated the kill zone in vitro and in vivo. We demonstrate that MWCNTs remain in the ablation region thus minimizing their migration to the systemic circulation. PMID: 24449052 [PubMed - as supplied by publisher] (Source: Annals of Biomedical Engineering)
Source: Annals of Biomedical Engineering - January 22, 2014 Category: Biomedical Engineering Authors: Rolland PH, Berry JL, Louis G, Velly L, Vidal V, Brige P, Mayakonda V, Carroll DL Tags: Ann Biomed Eng Source Type: research

Design and Mechanical Properties of a Novel Cerebral Flow Diverter Stent.
Abstract Brain arterial aneurysms are localised dilatation in the wall of cerebral arteries that are common among adult population and associated with high incidence of morbidity and mortality. Using flow diverter stent alone to treat cerebral aneurysm is recognized as a safe and effective method. However, flow diverter stents currently available have limitations due to their braided structures. In this paper a novel flow diverter stent is proposed. It is made out of nitinol tubes that provide adequate radial stiffness and tailored surface coverage to overcome problems of currently available braided stents while re...
Source: Annals of Biomedical Engineering - January 22, 2014 Category: Biomedical Engineering Authors: Ma J, You Z, Byrne J, Rizkallah RR Tags: Ann Biomed Eng Source Type: research

Multiuser Diversity for Secrecy Communications Using Opportunistic Jammer Selection: Secure DoF and Jammer Scaling Law
In this paper, we propose opportunistic jammer selection in a wireless security system for increasing the secure degrees of freedom (DoF) between a transmitter and a legitimate receiver (say, Alice and Bob). There is a jammer group consisting of $S$ jammers among which Bob selects $K$ jammers. The selected jammers transmit independent and identically distributed Gaussian signals to hinder the eavesdropper (Eve). Since the channels of Bob and Eve are independent, we can select the jammers whose jamming channels are aligned at Bob, but not at Eve. As a result, Eve cannot obtain any DoF unless it has more than $KN_{j}$ receiv...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

Low-Complexity Motion-Compensated Beamforming Algorithm and Architecture for Synthetic Transmit Aperture in Ultrasound Imaging
Synthetic transmit aperture (STA) has been widely investigated in ultrasound system recently with characteristics of high frame rate and low hardware cost. Since the high-resolution image (HRI) of STA is formed by summation of low-resolution images (LRIs), it is susceptible to inter-firing motions. In this paper, we propose a low-complexity global motion compensation algorithm. We use the common region of interest $({rm ROI}_{{rm com}})$ between different transmissions of STA imaging to beamform backward and forward beam vectors. Then, the magnitude and direction of motion can be evaluated by cross-correlations between spe...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

Non-Maximally Decimated Analysis/Synthesis Filter Banks: Applications in Wideband Digital Filtering
We present a new class of highly effective and low complexity digital filters for processing very wideband signals. Digital filtering for wideband signals is often limited by the number of arithmetic operations that has to be performed per input sampling interval. We will show the new architecture permits filtering to be performed on partitioned spectral segments of the input signal at significantly reduced sample rate. The digital filtering will be shown to include various tasks such as linear/non-linear phase finite impulse response (FIR) filtering, fractional delay filter among others. The proposed technique utilizes th...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

Convergence Rates of Distributed Nesterov-Like Gradient Methods on Random Networks
We consider distributed optimization in random networks where $N$ nodes cooperatively minimize the sum $sum _{i=1}^{N} f_{i}(x)$ of their individual convex costs. Existing literature proposes distributed gradient-like methods that are computationally cheap and resilient to link failures, but have slow convergence rates. In this paper, we propose accelerated distributed gradient methods that 1) are resilient to link failures; 2) computationally cheap; and 3) improve convergence rates over other gradient methods. We model the network by a sequence of independent, identically distributed random matrices ${W(k)}$ drawn from th...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

GESPAR: Efficient Phase Retrieval of Sparse Signals
We consider the problem of phase retrieval, namely, recovery of a signal from the magnitude of its Fourier transform, or of any other linear transform. Due to the loss of Fourier phase information, this problem is ill-posed. Therefore, prior information on the signal is needed in order to enable its recovery. In this work we consider the case in which the signal is known to be sparse, i.e., it consists of a small number of nonzero elements in an appropriate basis. We propose a fast local search method for recovering a sparse signal from measurements of its Fourier transform (or other linear transform) magnitude which we re...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

Maneuvering Target Detection via Radon-Fractional Fourier Transform-Based Long-Time Coherent Integration
Long-time coherent integration technique is one of the most important methods for the improvement of radar detection ability of a weak maneuvering target, whereas the integration performance may be greatly influenced by the across range unit (ARU) and Doppler frequency migration (DFM) effects. In this paper, a novel representation known as Radon-fractional Fourier transform (RFRFT) is proposed and investigated to solve the above problems simultaneously. It can not only eliminate the effect of DFM by selecting a proper rotation angle but also achieve long-time coherent integration without ARU effect. The RFRFT can be regard...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

Coalitional Games for Transmitter Cooperation in MIMO Multiple Access Channels
Cooperation between nodes sharing a wireless channel is becoming increasingly necessary to achieve higher throughputs in a wireless network. The problem of determining the feasibility and stability of cooperation between rational nodes in a wireless network is of great importance in understanding cooperative behavior. This paper addresses the stability of the grand coalition of transmitters signaling over a multiple access channel using the framework of cooperative game theory. The external interference experienced by each TX is represented accurately by modeling the cooperation game between the TXs in partition form. Sing...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

A Doppler Robust Design of Transmit Sequence and Receive Filter in the Presence of Signal-Dependent Interference
In this paper, we study the joint design of Doppler robust transmit sequence and receive filter to improve the performance of an active sensing system dealing with signal-dependent interference. The signal-to-noise-plus-interference (SINR) of the filter output is considered as the performance measure of the system. The design problem is cast as a max-min optimization problem to robustify the system SINR with respect to the unknown Doppler shifts of the targets. To tackle the design problem, which belongs to a class of NP-hard problems, we devise a novel method (which we call DESIDE) to obtain optimized pairs of transmit se...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

Multi-Stream Transmission for Highly Frequency Selective Channels in MIMO-FBMC/OQAM Systems
This paper addresses the joint design of MIMO precoding and decoding matrices for filter bank multicarrier (FBMC) systems based on OQAM, known as FBMC/OQAM. Existing solutions that support multi-stream transmission only give satisfactory performance in scenarios with high coherence bandwidth channels. To make progress towards the application of FBMC/OQAM to MIMO channels, we study the design of novel solutions that provide robustness against the channel frequency selectivity and support multi-stream transmission. To this end, two techniques have been devised under the criterion of minimizing the sum mean square error. The ...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

Distributed Finite-Horizon Fusion Kalman Filtering for Bandwidth and Energy Constrained Wireless Sensor Networks
This paper is concerned with the distributed finite-horizon fusion Kalman filtering problem for a class of networked multi-sensor fusion systems (NMFSs) in a bandwidth and energy constrained wireless sensor network. To satisfy the finite communication bandwidth, only partial components of each local vector estimate are allowed to be transmitted to the fusion center (FC) at a particular time, while each sensor intermittently sends information to the FC for reducing energy consumptions. At the FC end, a novel compensation strategy is proposed to compensate the untransmitted components of each local estimates, then a recursiv...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

Application of Manifold Separation to Polarimetric Capon Beamformer and Source Tracking
Two adaptive Capon methods that jointly estimate the azimuth-angle and polarization of the sources in a closed-form are proposed. It is shown that the azimuth-angles of the sources may be estimated from the roots of a complex-valued polynomial or by rooting a real-valued polynomial, instead. The latter method is particularly useful in tracking arbitrarily polarized sources in a sequential snapshot-by-snapshot manner using root-tracking techniques. The proposed polynomial rooting based methods are applicable to polarization sensitive arrays regardless of the array geometry including conformal arrays, and take into account a...
Source: IEEE Transactions on Signal Processing - January 21, 2014 Category: Biomedical Engineering Source Type: research

[Front cover]
Presents the cover/table of contents for this issue of the periodical. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - January 21, 2014 Category: Biomedical Engineering Source Type: research

Assessment of different carbohydrates as exogenous carbon source in cultivation of cyanobacteria.
Abstract Glucose is the substrate most widely used as exogenous carbon source for heterotrophic cultivation of cyanobacteria. Due to limited information about the use of different carbohydrates as carbon sources to support cyanobacterial heterotrophic metabolism, the objective of this work was to evaluate different monosaccharides (arabinose, fructose, galactose, glucose, mannose and xylose), disaccharides (lactose, maltose, sucrose and trehalose) and polysaccharides (carboxymethylcellulose, cassava starch, Hi-maize(®), maltodextrin Corn Globe 1805(®) and xylan) as exogenous carbon source for heterotrophic cultur...
Source: Bioprocess and Biosystems Engineering - January 21, 2014 Category: Biomedical Engineering Authors: Francisco EC, Franco TT, Wagner R, Jacob-Lopes E Tags: Bioprocess Biosyst Eng Source Type: research

Roy Greenberg 9 November 1964–7 December 2013
The European Journal for Vascular and Endovascular Surgery records with great sadness the untimely passing of Roy Greenberg on 7 December, 2013 at the age of just 49. At the Cleveland Clinic he was Vascular Surgeon in the Heart & Vascular Institute and also held joint appointments in the Imaging Institute, the Lerner Research Institute of Biomedical Engineering and was Director of Endovascular Research. He brought great distinction to himself and the Clinic in the field of endovascular surgery for complex aortic disease, winning international recognition for translation of his many innovations to clinical application. (Sou...
Source: European Journal of Vascular and Endovascular Surgery - January 21, 2014 Category: Surgery Authors: G. Hamilton Tags: In Memoriam Source Type: research

Unwanted Side Effect Becomes Advantage In Photoacoustic Imaging
Biomedical engineer Lihong Wang, PhD, and researchers in his lab work with lasers used in photoacoustic imaging for early-cancer detection and a close look at biological tissue. But sometimes there are limitations to what they can do, and as engineers, they work to find a way around those limitations.By Beth Miller (Source: Medical Design Online News)
Source: Medical Design Online News - January 20, 2014 Category: Medical Equipment Source Type: news

Biomedical Engineer Guohua Cao Secures Prestigious NSF CAREER Award To Pursue Sophisticated Imaging Technology
Currently, the medical community has limited ability in clinically assessing blockages called atherosclerotic plaques in the human body. (Source: Medical Design Online News)
Source: Medical Design Online News - January 20, 2014 Category: Medical Equipment Source Type: news

Coordinated Multicell Multiuser Precoding for Maximizing Weighted Sum Energy Efficiency
Energy efficiency optimization of wireless systems has become urgently important due to its impact on the global carbon footprint. In this paper we investigate energy efficient multicell multiuser precoding design and consider a new criterion of weighted sum energy efficiency, which is defined as the weighted sum of the energy efficiencies of multiple cells. This objective is more general than the existing methods and can satisfy heterogeneous requirements from different kinds of cells, but it is hard to tackle due to its sum-of-ratio form. In order to address this non-convex problem, the user rate is first formulated as a...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

High-Dimensional Screening Using Multiple Grouping of Variables
Screening is the problem of finding a superset of the set of non-zero entries in an unknown $p$-dimensional vector $beta^*$ given $n$ noisy observations. Naturally, we want this superset to be as small as possible. We propose a novel framework for screening, which we refer to as Multiple Grouping (MuG), that groups variables, performs variable selection over the groups, and repeats this process multiple number of times to estimate a sequence of sets that contains the non-zero entries in $beta^*$. Screening is done by taking an intersection of all these estimated sets. The MuG framework can be used in conjunction with any g...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Locality Statistics for Anomaly Detection in Time Series of Graphs
The ability to detect change-points in a dynamic network or a time series of graphs is an increasingly important task in many applications of the emerging discipline of graph signal processing. This paper formulates change-point detection as a hypothesis testing problem in terms of a generative latent position model, focusing on the special case of the Stochastic Block Model time series. We analyze two classes of scan statistics, based on distinct underlying locality statistics presented in the literature. Our main contribution is the derivation of the limiting properties and power characteristics of the competing scan sta...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Reducing Artifacts in JPEG Decompression Via a Learned Dictionary
The JPEG compression method is among the most successful compression schemes since it readily provides good compressed results at a rather high compression ratio. However, the decompressed result of the standard JPEG decompression scheme usually contains some visible artifacts, such as blocking artifacts and Gibbs artifacts (ringing), especially when the compression ratio is rather high. In this paper, a novel artifact reducing approach for the JPEG decompression is proposed via sparse and redundant representations over a learned dictionary. Indeed, an effective two-step algorithm is developed. The first step involves dict...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Stochastic Ordering of Interference in Large-Scale Wireless Networks
Stochastic orders are binary relations defined on probability distributions which capture intuitive notions like being larger or being more variable. This paper introduces stochastic ordering of interference distributions in large-scale networks modeled as point processes. Interference is a major performance-limiting factor in most wireless networks, thus it is important to characterize its statistics. Since closed-form results for the distribution of interference for such networks are only available in limited cases, it is of interest to compare network interference using stochastic orders, for two different point process...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Backhaul Limited Asymmetric Cooperation for MIMO Cellular Networks via Semidefinite Relaxation
Multicell cooperation has recently attracted tremendous attention because of its ability to eliminate intercell interference and increase spectral efficiency. However, the enormous amount of information being exchanged, including channel state information and user data, over backhaul links may deteriorate the network performance in a realistic system. This paper adopts a backhaul cost metric that considers the number of active directional cooperation links, which gives a first order measurement of the backhaul loading required in asymmetric Multiple-Input Multiple-Output (MIMO) cooperation. We focus on a downlink scenario ...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Intrinsically Optimal Bayesian Robust Filtering
When designing optimal filters it is often unrealistic to assume that the statistical model is known perfectly. The issue is then to design a robust filter that is optimal relative to an uncertainty class of processes. Robust filter design has been treated from minimax (best worst-case performance) and Bayesian (best average performance) perspectives. Heretofore, the Bayesian approach has involved finding a model-specific optimal filter, one that is optimal for some model in the uncertainty class. Lifting this constraint, we optimize over the full class from which the original optimal filters were obtained, for instance, o...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Distributed Detection in Sensor Networks Over Fading Channels With Multiple Antennas at the Fusion Centre
We develop new and optimal algorithms for distributed detection in sensor networks over fading channels with multiple receive antennas at the Fusion Centre (FC). Sensors observe a hidden physical phenomenon over fading channels and transmit their observations using the amplify-and-forward scheme over fading channels to the FC which is equipped with multiple antennas. We derive the optimal decision rules and the associated probabilities of detection and false alarm for three scenarios of Channel State Information (CSI) availability. For the most difficult case of unknown CSI, we develop two new algorithms to derive the opti...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Novel Blind Identification of LDPC Codes Using Average LLR of Syndrome a Posteriori Probability
Blind signal processing methods have been very popular recently since they can play crucial roles in the prevalent cognitive radio research. Blind encoder identification has drawn research interest lately. In this paper, we would like to tackle the blind identification of binary low-density parity-check (LDPC) codes for binary phase-shift keying (BPSK) signals. We propose a novel blind identification system which consists of three components, namely expectation-maximization (EM) estimator for signal amplitude and noise variance, log-likelihood ratio (LLR) estimator for syndrome a posteriori probabilities, and maximum avera...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Decomposition by Partial Linearization: Parallel Optimization of Multi-Agent Systems
We propose a novel decomposition framework for the distributed optimization of general nonconvex sum-utility functions arising naturally in the system design of wireless multi-user interfering systems. Our main contributions are i) the development of the first class of (inexact) Jacobi best-response algorithms with provable convergence, where all the users simultaneously and iteratively solve a suitably convexified version of the original sum-utility optimization problem; ii) the derivation of a general dynamic pricing mechanism that provides a unified view of existing pricing schemes that are based, instead, on heuristics...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

High-Throughput Energy-Efficient LDPC Decoders Using Differential Binary Message Passing
We report on fully parallel decoder implementations of (273, 191), (1023, 781), and (4095, 3367) finite geometry-based LDPC codes in 65 nm CMOS. Using the MDD-BMP algorithm, these decoders achieve respective areas of 0.28 ${rm mm}^{2}$ , 1.38 ${rm mm}^{2}$ , and 15.37 ${rm mm}^{2}$, average throughputs of 37 Gbps, 75 Gbps, and 141 Gbps, and energy efficiencies of 4.9 pJ/bit, 13.2 pJ/bit, and 37.9 pJ/bit with a 1.0 V supply voltage in post-layout simulations. At a reduced supply voltage of 0.8 V, these decoders achieve respective throughputs of 26 Gbps, 54 Gbps, and 94 Gbps, and energy efficiencies of 3.1 pJ/bit, 8.2 pJ/bit...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Ground Clutter Detection Using the Statistical Properties of Signals Received With a Polarimetric Radar
Polarimetric weather radars provide additional measurements that allow better characterization of the targeted medium. Because ground clutter has different polarimetric characteristics from weather echoes, dual-polarization measurements can be used to distinguish one from the other. Ground clutter and weather signals also have different statistical properties which can be utilized to distinguish one from the other. A test statistic, obtained from the generalized likelihood ratio test (GLRT), and a simple Bayesian classifier (SBC), with inputs from the mean and covariance of the received signals, are developed to detect gro...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Bi-Directional Training for Adaptive Beamforming and Power Control in Interference Networks
We study distributed algorithms for adapting transmit beamformers and linear receiver filters in a Time-Division Duplex Multiple-Input Multiple-Output (MIMO) interference network. Each transmitter transmits a single beam, and neither the transmitters nor receivers have a priori Channel State Information (CSI). Given a fixed set of powers, we present an adaptive version of the Max-SINR algorithm: pilot symbols are alternately transmitted in the forward direction (transmitters to receivers) and in the reverse direction (receivers to transmitters). Unlike previous channel estimation schemes, transmissions in each direction ar...
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research

Optimal Memory for Discrete-Time FIR Filters in State-Space
In this correspondence, we propose an efficient estimator of optimal memory (averaging interval) for discrete-time finite impulse response (FIR) filters in state-space. Its crucial property is that only real measurements and the filter output are involved with no reference and noise statistics. Testing by the two-state polynomial model has shown a very good correspondence with predicted values. Even in the worst case of the harmonic model, the estimator demonstrates practical applicability. (Source: IEEE Transactions on Signal Processing)
Source: IEEE Transactions on Signal Processing - January 17, 2014 Category: Biomedical Engineering Source Type: research