34 accepted papers
This paper presents a high-resolution coupled rank-(L<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf>,L<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf>,1) block-term decomposition-based near-f…
Spatial frequency estimation from a mixture of noisy sinusoids finds applications in various fields. The widely used subspace-based methods provide super-resolution parameter estimation at a low computational cost. However, they require an accurate array calibration, which is difficult for large ant…
Tensor completion has attracted increasing attention in signal processing, computer vision, and biomedical engineering. By using nuclear norm minimization, a tensor completion problem can be converted into a convex program and enjoys properties gained from matrix completion. The low rank property ha…
In this paper, we develop a near-field beamforming algorithm that is robust against aperture deformations. We derive analytical expressions on the bounds of the elements of the steering vector as a function of the known bounds of the coordinate displacement. We apply these bounds during the optimiza…
In this paper, we present an analytical proof of equivalence of the signal processing in the reduced aperture element space and in beamspace produced by the combination of multiple adjacent DFT beams with a subsequent constraining of the resulting magnitudes. This link finds applications in millimet…
In this paper, we present a precoder design for multi-user multiple-input multiple-output (MU-MIMO) broadcast systems with rate splitting at the transmitter. The proposed scheme applies to both underloaded and overloaded communication systems and supports the transmission of multiple common and priv…
Probability mass function (PMF) estimation using a low-rank model for the PMF tensor has gained increased popularity in recent years. However, its performance evaluation relied mostly on empirical testing. In this work, we derive theoretical bounds on the attainable performance under this model assu…
Reconfigurable intelligent surfaces (RISs) have been proposed recently as new technology to tune the wireless propagation channels in real-time. However, most of the current works assume single-RIS (S-RIS)-aided systems, which can be limited in some application scenarios where a transmitter might ne…
The efficient estimation of an approximate model order is essential for applications with multidimensional data if the observed low-rank data is corrupted by additive noise. Certain signal processing applications such as biomedical studies, where the data are collected simultaneously through heterog…
In this work, we propose a two-stage tensor-based receiver for joint channel, phase-noise (PN), and data estimation in MIMO-OFDM systems. First, we cast the received signal at the pilot subcarriers as a third-order PARAFAC model. Based on this model, we propose a closed-form algorithm based on the L…
Channel estimation in hybrid analog-digital massive MIMO systems is a challenging problem due to the high channel dimension, low signal-to-noise ratio before beamforming, and reduced number of radio-frequency chains. Compressed sensing based algorithms have been adopted to address these challenges b…
In this paper, we propose a new Multilinear Generalized Singular Value Decomposition (ML-GSVD) which allows to jointly factorize a set of matrices with one common dimension. The ML-GSVD is an extension of the Generalized Singular Value Decomposition (GSVD) for more than two matrices. In comparison w…
Channel state information (CSI) estimation in hybrid analog-digital (HAD) millimeter-wave (mmWave) massive MIMO systems is a challenging problem due to the high channel dimension and reduced number of radio-frequency chains. However, exploiting the channel sparsity, several methods have been propose…
In this paper, we develop simultaneous detection techniques of signals from multiple users for uplink multi-user MIMO (UL MU-MIMO) systems. Conventional detectors do not take the detection delay into account. Two parallelizing access methods are proposed for UL MU-MIMO systems. The multiple uplink u…
Tensor decompositions are regarded as a powerful tool for multidimensional signal processing. In this contribution, we focus on the well-known Canonical Polyadic (CP) decomposition and present a first-order perturbation analysis of the SEmi-algebraic framework for approximate CP decompositions via S…
Tensor contraction is a multilinear algebra operator that defines an inner product between two tensors with compatible dimensions. In this work, we show that the MIMO-OFDM (Multiple-Input Multiple-Output - Orthogonal Frequency Division Multiplexing) received signal can be modeled by means of the ten…
In its basic, fully blind form, Independent Component Analysis (ICA) does not rely on a particular statistical model of the sources, but only on their mutual statistical independence, and therefore does not admit a Maximum Likelihood (ML) estimation framework. In semi-blind scenarios statistical mod…
The “Sequentially Drilled” Joint Congruence (SeDJoCo) transformation is a set of matrix transformation equations, which coincide with the Likelihood Equations for semi-blind source separation, when each source is modeled as a zero-mean Gaussian process with a known (and distinct) temporal covariance…
In this paper we develop space-time block codes for unique word - orthogonal frequency division multiplexing (UW-OFDM) systems to fully exploit the diversity gain when the channel state information is not available at the transmitter. To this end, we propose two novel space-time block codes (STBCs)…
Multi-beam mobile satellite systems aim at providing broadband and high speed mobile services over a large area to achieve a high system throughput, where hybrid space-ground beamforming is one of the most promising candidates for ground-based beamforming techniques. It not only reduces the feeder l…
In this paper we study the parameter estimation problem of an OFDM based joint wideband SIMO radar and communication system. The parameters to be estimated are time delays, relative velocities, and angle of arrival (DoA) pairs of radar targets. Due to the wideband assumption the received signal on d…
Joint EigenValue Decomposition (JEVD) algorithms are widely used in many application scenarios. These algorithms can be divided into different categories based on the cost function that needs to be minimized. Most of the frequently used algorithms in the literature use indirect least square (LS) cri…
This paper provides a second-order (SO) analytical performance analysis of the 1-D Standard ESPRIT algorithm. Existing performance analysis frameworks are based on first-order (FO) approximations of the parameter estimation error, which are asymptotic in the effective signal-to-noise ratio (SNR), i.…
Estimating the directions of arrival (DOA) of coexisting circular and strictly second-order (SO) non-circular (NC) signals has recently emerged as an active field of research. In previous work, we have proposed two ESPRIT-type algorithms, i.e., C-NC Standard ESPRIT and C-NC Unitary ESPRIT, for this…
This paper presents a new perspective of beamforming designs in Coordinated Multi-Point (CoMP) downlink systems that are combined with multicast schemes. The beamformer computation is expressed as a joint matrix transformation that can be regarded as an extension of the "Sequentially Drilled" Joint…
With the increased importance of the CP decomposition (CANDECOMP/PARAFAC decomposition), efficient methods for its calculation are necessary. In this paper we present an extension of the SECSI (SEmi-algebraic framework for approximate CP decomposition via SImultaneous matrix diagonalization) that is…
In this paper we study the hybrid precoding design problem for a frequency selective massive MIMO channel, e.g., the millimeter wave (mmWave) massive MIMO channel. In contrast to a traditional MIMO system, a hybrid analog-digital MIMO scheme is preferred for massive MIMO systems due to the high cost…
In the context of Maximum Likelihood (ML) source separation in a semi-blind scenario, where the spectra of the sources are known and distinct, the likelihood equations amount to a set of matrix decompositions (known as the "Sequentially Drilled" Joint Congruence Transformation (SeDJoCo)). However, q…
Direction of arrival (DOA) estimation via sparse signal recovery (SSR) has recently attracted a considerable research interest due to its various advantages over the conventional DOA estimation methods. Yet, the performance of the SSR-based algorithms can be further enhanced by exploiting the struct…
We propose a subspace-based Widely Linear (WL) blind channel estimation scheme based on the iterative power method for the WL constrained minimum variance Code Division Multiple Access (CDMA) receiver. The novel technique approximates the noise subspace by using a matrix power and the WL processing…
This paper addresses the distributed beamforming problem, where widely-linear (WL) processing is employed at both the relays and the receiver to take advantage of strictly second-order (SO) noncircular source signals. We consider a single-antenna communication pair in a relay network, which suffers…
Recently, ESPRIT-based parameter estimation algorithms have been developed to exploit the structure of signals from strictly second-order (SO) non-circular (NC) sources. They achieve a higher estimation accuracy and can resolve up to twice as many sources. However, these NC methods assume that all t…
In this paper we study the achievable rate region of an FBMC based two-way decode-and-forward relaying system. Unlike a CPOFDM system, the FBMC based systems experience inter-carrier interference and inter-symbol interference especially in a highly frequency selective channel. To calculate the resul…
In this contribution we propose two new designs of transmit and receive processing for multi-user multiple-input-multiple-output (MIMO) downlink systems that employ filter bank based multicarrier with offset quadrature amplitude modulation (FBMC/OQAM). Our goal is to overcome the limits on the chann…