MOTA , João

A new multi-antenna coding framework is proposed for space-time-frequency (STF) transmissions over broadband multiple input multiple output (MIMO) systems based on orthogonal frequency division multiplexing (OFDM). A tensor decomposition known as PARAFAC is used as the core of a multi- stream space-time-frequency coder that jointly multiplex...

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This paper considers the downlink of a multiple-input multiple-output (MIMO) code-division multiple-access (CDMA) system based on space-time spreading (STS) using multiuser/multicode transmission. A constrained tensor model is proposed for the STS transmitted signal. The new STS model generalizes existing ones by allowing multiuser spatial...

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In some antenna array-based wireless communication systems the received signal is multidimensional and can be treated as a tensor (3D array) instead of a matrix (2D array). In this paper, we make use of a generalized tensor decomposition known as constrained Block-PARAFAC and propose a tensor (3D) model for the signal received by three types of...

International 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...

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 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 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...

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...

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...

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...

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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...

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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....

We propose a blind FIR channel identification method based on the parallel factor (Parafac) analysis of a 3rd-order tensor composed of the 4-th order output cumulants. Our algorithm is based on a single-step least squares (LS) minimization procedure instead of using classical three-step alternating least squares (ALS) methods. Using a...

Two semi-blind tensor based receivers for uplink radio over fiber (ROF) nonlinear instantaneous channels in a multiuser code division multiple access (CDMA) environment are proposed in this paper. These receivers are based on the PARAFAC decomposition of a tensor (three-way array) composed of received signals with space, time and code...