Renato R. Lopes

Learn More
—In this paper we propose low-complexity algorithms for estimating flat, time-varying and spatially correlated MIMO channels. The proposed estimators employ Kalman filters to track the channel in orthogonal space-time block coded systems. After developing a state-space model for spatially correlated MIMO channels, we show that the proposed estimators can be(More)
We derive and analyze two modified Kalman channel estimators (KCE) for time-varying, flat, spatially correlated MIMO channels in systems employing orthogonal space-time block codes: the steady-state KCE, which is less complex than the KCE, and the fading memory KCE, which is more robust to model mismatch.
Hybrid multiple-input multiple-output (MIMO) transceiver scheme (HMTS) combines transmit diversity and spatial multiplexing, thus achieving at the same time the two possible spatial gains offered by MIMO channels. In the design of HMTS spatial diversity and spatial multiplexing branches are disposed in parallel in order to achieve diversity and multiplexing(More)
The goal of this work is to provide a brief overview of some recent advances in the field of seismic signal processing. In particular, we shall focus on tasks such as multiple attenua-tion and coherent noise elimination, paying special attention to the application of signal separation methods that are able to take into account prior information such as(More)
Crosstalk is one of the main impairments of digital subscriber line (DSL) systems. To combat this impairment, several techniques were proposed in the literature that employ some form of precoding in the downstream. However, most existing bit allocation algorithms are not applicable to precoded DSL systems when the power in each transmission line is(More)
In this paper, we propose a suboptimal algorithm to assign MIMO transmit structures subject a required quality of service (QoS). In particular, we use the error probability of MIMO structures designed to achieve diversity and multiplexing gains as the QoS target. This suboptimal algorithm provides two MIMO structures that are hybrids between diversity and(More)
  • 1