Raúl A. Casas

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This work studies the CM criterion applied to equalization with AR channel receivers motivated by recently proposed blind IIR algorithms [6], [7], but may also be used for initializing a blind adaptive DFE. Blind IIR equalization is of practical interest for two main reasons: the IIR structure not only provides a parsimonious representation of a linear(More)
The Convolutional Neural Network (CNN) is a breakthrough technique in object classification and pattern recognition. It has enabled computers to achieve performance superior to humans in specialized image recognition tasks. Prior art CNNs learn object features by stacking multiple convolutional/non-linear layers in sequence on top of a classifier. In this(More)
We analyze a blind channel impulse response identification scheme based on the cross correlation of blind symbol estimates with the received signal. The symbol estimates specified are those minimizing the Godard (or constant modulus) criterion, for which mean-squared symbol estimation error bounds have recently been derived. In this paper, we derive upper(More)
Prediction error methods are considered for identi,cation of the forward linear dynamics of nonlinear feedback closed-loop systems which operate in a perturbed stable limit cycle. A model of the signals measured in a neighborhood of the limit cycle is presented and shown to satisfy a quasistationarity property. Quasistationarity is then used to prove that(More)
We introduce an architecture for a programmable IEEE 802.11ah Wi-Fi modem based on a new Cadence Xtensa-based low-energy DSP. The design is based on a methodology for partitioning the system into hardware and software components that takes into account power consumption, silicon area and the need for programmability. Physical layer software functions avail(More)
When applied to decision feed back equahzation (DFE), the conventional minimum mean square error (MMSE) design approach is shown to be deficient in performance, making a number of recent contributions in the literature questionable. By taking into account the adverse effects of the nonlinear recursive character of the DFE which makes its presence felt in(More)
Bussgang algorithms are a class of simple stochastic gradient type solutions for blind channel equalization. In this contribution we investigate the degradation of performance in the source estimation resulting from the stochastic jitter around the stationary points of Bussgang algorithms (which correspond to the equalizers of the channel). More precisely,(More)