DE ALMEIDA , André

In several signal processing applications for wireless communications, the received signal is multidimensional in nature and may exhibit a multilinear algebraic structure. In this context, the PARAFAC tensor decomposition has been the subject of several works in the past six years. However, generalized tensor decompositions are necessary for...

Some tensor prerequisites with a particular emphasis on mode combination using Kronecker products of canonical vectors that makes easier matricization operations, are first reviewed. Then, after a brief reminder of PARAFAC and Tucker models, two families of constrained tensor models, the co-called PARALIND/CONFAC and PARATUCK models, are...

This paper presents a unified tensor model for space-frequency spreading-multiplexing (SFSM) multiple-input multiple-output (MIMO) wireless communication systems that combine space- and frequency-domain spreadings, followed by a space-frequency multiplexing. Spreading across space (transmit antennas) and frequency (subcarriers) adds resilience...

We first introduce a new class of tensor models for fourth-order tensors, referred to as "nested PARAFAC models." Then, we present a space-time-frequency (STF) coding scheme for multiple antenna orthogonal frequency division multiplexing systems. This scheme, called double Khatri-Rao STF (D-KRSTF) coding, combines time-domain spreading with...

International audience

In this paper, we first introduce two new classes of constrained tensor models that we call generalized PARATUCK- (N1, N) and Tucker- (N1, N) models. A new tensor space-time-frequency (TSTF) coding structure is then proposed for MIMO OFDM-CDMA wireless communication systems. Two semi-blind receivers relying on the new generalized PARATUCK model...

In this paper, we propose two new space-time (ST) coding schemes for multiple-antenna signalling based on multiple Khatri-Rao and Kronecker products of symbol matrices, denoted MKRST and MKronST codings, respectively. These new coding schemes generalize the standard Khatri-Rao coding by introducing extra space/time diversities due to a mutual...

This paper presents a constrained Tucker-3 model for blind beamforming. The constrained structure of this model is parameterized by two constraint matrices that capture the spatial and temporal structure of the channel. We first present a generalized Tucker-3 model that considers a multipath propagation scenario with large delay spread and...

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In this paper, we present a new tensor decomposition that consists in decomposing a third-order tensor into a triple sum of rank-one tensor factors, where interactions involving the components of di®erent factors are allowed. The interaction pattern is controlled by three constraint matrices composed of canonical vectors. An application of this...

National audience

In this paper, we present new space-time multiplexing codes (STMC) for multiple-antenna transmissions, which rely on a three-dimensional tensor modeling of the transmitted/received signals. The proposed codes combine spatial multiplexing and space-time coding by spreading a linear combination of different sub-streams of data over the space and...

A new multiple-antenna transmission framework is proposed for multicarrier multiple-access wireless communication systems. The trilinear tensor (PARAFAC) decomposition is used to model a multiple-input multiple-output (MIMO) space-time-frequency (STF) scheme which consists in jointly multiplexing and spreading multiple data streams across space...

National audience

We address the problem of blind separation of non-synchronous statistically independent sources from underdetermined mixtures. A deterministic tensor-based receiver exploiting symbol rate diversity by means of parallel deflation is proposed. By resorting to bank of samplers at each sensor output, a set of third-order tensors is built, each one...

In this paper, we consider a point-to-multipoint downlink multiuser wireless communication system, where a multiple-antenna base station simultaneously transmits data to several users equipped with multiple receive antennas. The transmit antenna array is partitioned into transmission blocks, each one being associated with a given user....

In this work we propose a new method for estimation of multipath parameters in the context of mobile communications. The proposed method is an effective way to exploit the fact that the paths amplitudes are fast-varying while angles and delays are slowly-varying over multiple time-slots. By relying on such a multislot invariance of angles and...

In this paper, we consider an uplink multiple-antenna code-division multiple-access (CDMA) system linking several multiple-antenna mobile users to one multiple-antenna base station. For this system, a constrained third-order tensor decomposition is introduced for modeling the multiple-antenna transmitter as well as the received signal. The...

In this paper, we formulate a new tensor decomposition herein called constrained factor (CONFAC) decomposition. It consists in decomposing a third-order tensor into a triple sum of rank-one tensor factors, where interactions involving the components of different tensor factors are allowed. The interaction pattern is controlled by three...

International audience

In this paper, we present a new space-time spreading-multiplexing model for multiple-input multiple-output (MIMO) wireless communication systems relying on a tensor modeling of the transmitted and received signals. At the transmitter, we exploit the core of a PARATUCK-2 tensor model composed of a precoding matrix and two allocation matrices...

In this paper, we propose a deterministic tensor-based approach for joint channel and symbol estimation in the context of multiuser single-input multi-output (SIMO) CDMA communication systems. We use a new nonlinear (NL) coding allowing to obtain a third-order block-Tucker2 model for the signals received by multiple receive antennas, with a...