@article{38230, author = {{Koch, Benjamin and Noé, Reinhold and Sandel, David and Mirvoda, Vitali and Omar, Jan and Puntsri, Kidsanapong}}, journal = {{IEEE Photonics Technology Letters}}, number = {{9}}, pages = {{798--801}}, title = {{{20-Gb/s PDM-RZ-DPSK Transmission With 40 krad/s Endless Optical Polarization Tracking}}}, doi = {{10.1109/LPT.2013.2251877}}, volume = {{25}}, year = {{2013}}, } @article{37672, abstract = {{AbstractLet ${F}_{BC} (\lambda , k; t)$ be the Heckman–Opdam hypergeometric function of type BC with multiplicities $k= ({k}_{1} , {k}_{2} , {k}_{3} )$ and weighted half-sum $\rho (k)$ of positive roots. We prove that ${F}_{BC} (\lambda + \rho (k), k; t)$ converges as ${k}_{1} + {k}_{2} \rightarrow \infty $ and ${k}_{1} / {k}_{2} \rightarrow \infty $ to a function of type A for $t\in { \mathbb{R} }^{n} $ and $\lambda \in { \mathbb{C} }^{n} $. This limit is obtained from a corresponding result for Jacobi polynomials of type BC, which is proven for a slightly more general limit behavior of the multiplicities, using an explicit representation of Jacobi polynomials in terms of Jack polynomials. Our limits include limit transitions for the spherical functions of non-compact Grassmann manifolds over one of the fields $ \mathbb{F} = \mathbb{R} , \mathbb{C} , \mathbb{H} $ when the rank is fixed and the dimension tends to infinity. The limit functions turn out to be exactly the spherical functions of the corresponding infinite-dimensional Grassmann manifold in the sense of Olshanski.}}, author = {{Rösler, Margit and Koornwinder, Tom and Voit, Michael}}, issn = {{0010-437X}}, journal = {{Compositio Mathematica}}, keywords = {{Algebra and Number Theory}}, number = {{8}}, pages = {{1381--1400}}, publisher = {{Wiley}}, title = {{{Limit transition between hypergeometric functions of type BC and type A}}}, doi = {{10.1112/s0010437x13007045}}, volume = {{149}}, year = {{2013}}, } @article{38038, author = {{Rösler, Margit and Voit, Michael}}, journal = {{Journal of Lie Theory 23}}, number = {{4}}, pages = {{899----920}}, publisher = {{Heldermann }}, title = {{{Olshanski spherical functions for infinite dimensional motion groups of fixed rank}}}, doi = {{10.48550/ARXIV.1210.1351}}, year = {{2013}}, } @inproceedings{24351, abstract = {{We demonstrate the first 80 Gb/s decision feedback equalizer in various electrical and optical applications. The device, designed in SiGe:C BiCMOS 0.13 μm technology, enables error-free data recovery of heavily distorted signals transmitted at a bandwidth less than 30% of their bit rate. The fastest nonlinear electrical equalizer reported yet utilizes a novel 1-tap look-ahead architecture.}}, author = {{Möller, Lothar and Awny, Ahmed and Junio, Josef and Scheytt, Christoph and Thiede, Andreas}}, booktitle = {{Optical Fiber Communication Conference}}, title = {{{80 Gb/s Decision Feedback Equalizer for Intersymbol Interference}}}, doi = {{10.1364/OFC.2013.OW4B.2 }}, year = {{2013}}, } @article{38477, author = {{Hussin, Saleh and Puntsri, Kidsanapong and Noé, Reinhold}}, issn = {{1041-1135}}, journal = {{IEEE PHOTONICS TECHNOLOGY LETTERS}}, number = {{12}}, pages = {{1099--1102}}, title = {{{Analysis of Partial Pilot Filling Phase Noise Compensation for CO-OFDM Systems}}}, doi = {{10.1109/LPT.2013.2258332}}, volume = {{25}}, year = {{2013}}, } @article{38369, author = {{Koch, Benjamin and Noé, Reinhold and Sandel, David and Mirvoda, Vitali and Omar, Jan and Puntsri, Kidsanapong}}, issn = {{1041-1135}}, journal = {{IEEE PHOTONICS TECHNOLOGY LETTERS}}, number = {{9}}, pages = {{798--801}}, title = {{{20-Gb/s PDM-RZ-DPSK Transmission With 40 krad/s Endless Optical Polarization Tracking}}}, doi = {{10.1109/LPT.2013.2251877}}, volume = {{25}}, year = {{2013}}, } @inproceedings{38217, author = {{Jan, Omar and Al-Bermani, Ali and Puntsri, Kidsanapong and Sandel, David and Woerdehoff, Christian and Rueckert, Ulrich and Noé, Reinhold}}, booktitle = {{2013 ITG Symposium Proceedings - Photonic Networks}}, pages = {{1--3}}, title = {{{An Experiment of Coherent Optical DFT-spread OFDM with Laser Phase Noise}}}, year = {{2013}}, } @article{40072, author = {{Luks, Tomasz}}, issn = {{0926-2601}}, journal = {{Potential Analysis}}, number = {{1}}, pages = {{29--67}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Boundary Behavior of α-Harmonic Functions on the Complement of the Sphere and Hyperplane}}}, doi = {{10.1007/s11118-012-9321-x}}, volume = {{39}}, year = {{2013}}, } @inproceedings{40788, abstract = {{In this paper we propose a new interference alignment (IA) algorithm specifically designed to work with structured channels (e.g., diagonal or block-diagonal). Multiple-input multiple-output (MIMO) structured channels arise when symbol extensions -either in time or frequency- are employed jointly with the spatial dimension in the design of the precoders. In this case, the rank constraint in the direct channels must explicitly be taken into account into the optimization problem to ensure that there is no degrees-of-freedom (DoF) loss. To this end, we propose an algorithm that minimizes the interference leakage while ensuring that the direct links are full rank and the transmitters satisfy a power constraint. The algorithm is based upon an alternating optimization procedure, which solves a generalized eigenvalue problem at each step. We show through simulations the advantages of the proposed algorithm in several scenarios that use symbols extensions or improper (a.k.a. asymmetric) signalling.}}, author = {{Lameiro, Christian and Santamaría, Ignacio}}, booktitle = {{Proc. IEEE Work. Signal Process. Advances in Wireless Comm.}}, title = {{{An Interference Alignment Algorithm for Structured Channels}}}, doi = {{10.1109/SPAWC.2013.6612059}}, year = {{2013}}, } @inproceedings{40789, abstract = {{It has been recently shown that for the 3-user single-input single-output (SISO) interference channel with constant channel coefficients, a maximum of 1.2 degrees-of-freedom (DoF) are achievable using linear interference alignment schemes when improper (a.k.a. asymmetric) Gaussian signaling is applied. In this paper, we study the 4-user SISO interference channel and provide inner and outer bounds for the total number of DoF achievable for this channel. We prove that at least 4/3 DoF are achievable for the 4-user channel using also linear interference alignment techniques and improper signaling. A simple converse proof shows that no more than 8/5 DoF are achievable for this scheme. Simulation results seem to indicate that the inner bound is in fact tight for this channel, and serve to illustrate the sum-rate improvement with respect to time division multiple access (TDMA) techniques.}}, author = {{Lameiro, Christian and Santamaría, Ignacio}}, booktitle = {{Proc.\ IEEE Int.\ Conf.\ Comm.}}, title = {{{Degrees-of-Freedom for the 4-User SISO Interference Channel with Improper Signaling}}}, doi = {{10.1109/ICC.2013.6655009}}, year = {{2013}}, } @inproceedings{40792, abstract = {{OCT images of human aorta from aneurysms reveals elastin disorder and smooth muscle cell alteration when visualizing the intima and media layers of the aortic wall. Results correlate with pathologist diagnosis in aneurysmatic and control aortas.}}, author = {{Real, Eusebio and Eguizabal, Alma and Ponton, Alejandro and Val-Bernal, J. Fernando and Mayorga, Marta and Revuelta, Jose and Lopez-Higuera, Jose and Conde, Olga}}, booktitle = {{European Conferences on Biomedical Optics}}, title = {{{Optical Coherence Tomography Assessment of Vessel Wall Degradation in Aneurysmatic Thoracic Aortas}}}, year = {{2013}}, } @inproceedings{40795, author = {{Stein, Manuel and Wendler, Friederike and Mezghani, Amine and Nossek, Josef A.}}, booktitle = {{Proc.\ IEEE Int.\ Conf.\ Acoustics, Speech and Signal Process.}}, title = {{{Quantization-loss reduction for signal parameter estimation}}}, year = {{2013}}, } @inproceedings{40798, abstract = {{Texture analysis of light scattering in tissue is proposed to obtain diagnostic information from breast cancer specimens. Light scattering measurements are minimally invasive, and allow the estimation of tissue morphology to guide the surgeon in resection surgeries. The usability of scatter signatures acquired with a micro-sampling reflectance spectral imaging system was improved utilizing an empirical approximation to the Mie theory to estimate the scattering power on a per-pixel basis. Co-occurrence analysis is then applied to the scattering power images to extract the textural features. A statistical analysis of the features demonstrated the suitability of the autocorrelation for the classification of notmalignant (normal epithelia and stroma, benign epithelia and stroma, inflammation), malignant (DCIS, IDC, ILC) and adipose tissue, since it reveals morphological information of tissue. Non-malignant tissue shows higher autocorrelation values while adipose tissue presents a very low autocorrelation on its scatter texture, being malignant the middle ground. Consequently, a fast linear classifier based on the consideration of just one straightforward feature is enough for providing relevant diagnostic information. A leave-one-out validation of the linear classifier on 29 samples with 48 regions of interest showed classification accuracies of 98.74% on adipose tissue, 82.67% on non-malignant tissue and 72.37% on malignant tissue, in comparison with the biopsy H and E gold standard. This demonstrates that autocorrelation analysis of scatter signatures is a very computationally efficient and automated approach to provide pathological information in real-time to guide surgeon during tissue resection.}}, author = {{Eguizabal, Alma and Laughney, Ashley M. and Garcia-Allende, P. Beatriz and Krishnaswamy, Venkataramanan and Wells, Wendy A. and Paulsen, Keith D. and Pogue, Brian W. and Lopez-Higuera, Jose and Conde, Olga M.}}, booktitle = {{SPIE Photonics West BIOS, VIII Biomedical Applications of Light Scattering}}, title = {{{Linear classifier and textural analysis of optical scattering images for tumor classification during breast cancer extraction}}}, year = {{2013}}, } @inproceedings{40799, abstract = {{Fractal analysis combined with a label-free scattering technique is proposed for describing the pathological architecture of tumors. Clinicians and pathologists are conventionally trained to classify abnormal features such as structural irregularities or high indices of mitosis. The potential of fractal analysis lies in the fact of being a morphometric measure of the irregular structures providing a measure of the object’s complexity and self-similarity. As cancer is characterized by disorder and irregularity in tissues, this measure could be related to tumor growth. Fractal analysis has been probed in the understanding of the tumor vasculature network. This work addresses the feasibility of applying fractal analysis to the scattering power map (as a physical modeling) and principal components (as a statistical modeling) provided by a localized reflectance spectroscopic system. Disorder, irregularity and cell size variation in tissue samples is translated into the scattering power and principal components magnitude and its fractal dimension is correlated with the pathologist assessment of the samples. The fractal dimension is computed applying the box-counting technique. Results show that fractal analysis of ex-vivo fresh tissue samples exhibits separated ranges of fractal dimension that could help classifier combining the fractal results with other morphological features. This contrast trend would help in the discrimination of tissues in the intraoperative context and may serve as a useful adjunct to surgeons.}}, author = {{Eguizabal, Alma and Laughney, Ashley M. and Krishnaswamy, Venkataramanan and Wells, Wendy A. and Paulsen, Keith D. and Pogue, Brian W. and Lopez-Higuera, Jose and Conde, Olga M.}}, booktitle = {{SPIE Photonics West BIOS, VIII Biomedical Applications of Light Scattering}}, title = {{{Fractal analysis of scatter imaging signatures to distinguish breast pathologies}}}, year = {{2013}}, } @inproceedings{40790, abstract = {{Endogenous tissue contrast such as decreased hemoglobin saturation aids in cancer localization. Principal component analysis is proposed for blindly oxygenation extraction from total diffuse reflectance spectra obtained by the diffusion approximation.}}, author = {{Eguizabal, Alma and Garcia-Allende, Pilar and Jentoft, Karin and Symvoulidis, Panagiotis and Lopez-Higuera, Jose and Ntziachristos, Vasilis and Conde, Olga M.}}, booktitle = {{European Conferences on Biomedical Optics}}, title = {{{Principal Component Analysis to extract blood oxygenation from theoretical modeling of total diffuse reflectance spectra}}}, year = {{2013}}, } @inproceedings{40777, abstract = {{The paper deals with global stability analysis of linear control systems with saturation in feedback driven by an external input. Various new criteria based on non-quadratic Lyapunov functions are proposed, that unlike many previous results, offer better account for the role of the external excitation by providing input-dependent conditions for stability of solutions. For example, it is shown that even if the system fails to satisfy the incremental version of the circle criterion, the stability is guaranteed whenever the uniform root mean square value of the input signal is less than a computable threshold. The general theoretical results are illustrated in the case of the double integrator closed by a saturated linear feedback with an external excitation.}}, author = {{Yu. Pogromsky, Alexander and Matveev, Alexey S. and Chaillet, Antoine and Rüffer, Björn S.}}, booktitle = {{Proc. 52nd IEEE Conf. Decis. Control}}, pages = {{5903–5908}}, title = {{{Input-dependent stability analysis of systems with saturation in feedback}}}, year = {{2013}}, } @inproceedings{40783, author = {{Tong, Jun and Schreier, Peter J.}}, booktitle = {{Proc. IEEE Wireless Comm. Networking Conf. (WCNC)}}, title = {{{Linear equalization in communications with mismatched modeling using Krylov subspace expansion}}}, year = {{2013}}, } @article{40070, author = {{Graczyk, Piotr and Jakubowski, Tomasz and Luks, Tomasz}}, issn = {{1385-1292}}, journal = {{Positivity}}, number = {{4}}, pages = {{1043--1070}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Martin representation and Relative Fatou Theorem for fractional Laplacian with a gradient perturbation}}}, doi = {{10.1007/s11117-012-0220-6}}, volume = {{17}}, year = {{2013}}, } @article{40796, abstract = {{In this paper we study the existence of locally most powerful invariant tests (LMPIT) for the problem of testing the covariance structure of a set of Gaussian random vectors. The LMPIT is the optimal test for the case of close hypotheses, among those satisfying the invariances of the problem, and in practical scenarios can provide better performance than the typically used generalized likelihood ratio test (GLRT). The derivation of the LMPIT usually requires one to find the maximal invariant statistic for the detection problem and then derive its distribution under both hypotheses, which in general is a rather involved procedure. As an alternative, Wijsman’s theorem provides the ratio of the maximal invariant densities without even finding an explicit expression for the maximal invariant. We first consider the problem of testing whether a set of N-dimensional Gaussian random vectors are uncorrelated or not, and show that the LMPIT is given by the Frobenius norm of the sample coherence matrix. Second, we study the case in which the vectors under the null hypothesis are uncorrelated and identically distributed, that is, the sphericity test for Gaussian vectors, for which we show that the LMPIT is given by the Frobenius norm of a normalized version of the sample covariance matrix. Finally, some numerical examples illustrate the performance of the proposed tests, which provide better results than their GLRT counterparts.}}, author = {{Ramírez, D. and Vía, J. and Santamaría, I. and Scharf, L. L.}}, journal = {{IEEE Trans.\ Inform.\ Theory}}, number = {{4}}, pages = {{2128–2141}}, title = {{{Locally Most Powerful Invariant Tests for Correlation and Sphericity of Gaussian Vectors}}}, doi = {{10.1109/TIT.2012.2232705}}, volume = {{59}}, year = {{2013}}, } @article{40800, abstract = {{In this paper, we study the multiple-input multiple-output two-way relay channel (MIMO-TWRC) when the nodes and relay use analog beamforming. Following the amplify-andforward (AF) strategy, the problem consists of finding the transmit and receive beamformers of the nodes and relay (as well as the power allocated to each one) that achieve the boundary of the optimal rate region. To solve it, we first express the optimal node beamformers in terms of relay beamformers and then show that the optimal rate region can efficiently be characterized using convex optimization techniques. We also extend our study to the multiple-relay scenario when the source nodes are single antenna and propose a distributed algorithm to compute the relay beamforming matrices. The proposed algorithm consists of solving two different subproblems. First, each individual TWRC is optimized independently. Next, a distributed beamforming is applied to make the signals from the relays add up coherently at the source nodes. Numerical examples are provided to illustrate the performance of the proposed techniques and to compare the performance of analog beamforming architectures against conventional MIMO schemes that operate at the baseband.}}, author = {{Lameiro, Christian and Vía, Javier and Santamaría, Ignacio}}, journal = {{IEEE Trans. Veh. Techn.}}, pages = {{642–654}}, title = {{{Amplify-and-Forward Strategies in the Two-Way Relay Channel with Analog Tx-Rx Beamforming}}}, doi = {{10.1109/TVT.2012.2226612}}, volume = {{62}}, year = {{2013}}, }