Harold Artés

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It is well known that suboptimal detection schemes for multiple-input multiple-output (MIMO) spatial multiplexing systems (equalization-based schemes as well as nulling-and-cancelling schemes) are unable to exploit all of the available diversity, and thus, their performance is inferior to ML detection. Motivated by experimental evidence that this inferior(More)
The conventional nulling-and-cancelling (NC) detection scheme for MIMO systems uses the layerwise post-detection mean-square errors (MSEs) as reliability measures for layer sorting. These MSEs are average measures that do not depend on the received vector. We propose a novel dynamic nulling-and-cancelling (DNC) detector that performs "dynamic" layer sorting(More)
We discuss and compare the most important detection techniques for MIMO spatial multiplexing wireless systems, focusing on their performance and computational complexity. Our analysis shows that the limited performance of conventional suboptimal detection techniques is primarily caused by their inability to cope with poorly conditioned channels. The(More)
It is known that conventional nulling-and-canceling (NC) detection for multiple-input/multiple-output (MIMO) systems cannot exploit all of the available diversity, and, thus, its performance is significantly inferior to that of maximum likelihood (ML) detection. Conventional NC employs the layerwise postequalization signal-to-noise ratios (SNRs) as(More)
It is known that suboptimal (equalization-based and nulling-and-cancelling) detectors for MIMO spatial multiplexing systems cannot exploit all of the available diversity. Motivated by the insight that this behavior is mainly caused by poorly conditioned channel realizations, we propose the line-search detector (LSD) that is robust to poorly conditioned(More)
We propose two methods for the estimation of scattering functions of random time-varying channels. In contrast to existing methods, our methods exploit the underspread property of these channels to achieve good estimation performance and low computational complexity. The first method uses a dedicated sounding to measure the channel. The second method uses(More)
It is well known that suboptimal detection schemes for MIMO spatial multiplexing systems (equalization-based as well as nulling-and-cancelling detectors) cannot exploit all of the available diversity. In this paper, we show that this inferior performance is primarily caused by poorly conditioned channel realizations. We then present the novel(More)
In MIMO receivers, the channel state needs to be estimated for equalization, detection, and for feedback to the transmitter in case of adaptive modulation and coding. Most current iterative [7, 16, 27] and non-iterative [25] schemes in the single-user MIMO case are training-based and rely on the transmission of pilot symbols. Alternatives to pilot-based(More)