Signal synchronization and channel estimation/equalization functions for DVB-T software-defined receivers

The aim of this master thesis work is the implementation of the synchronization and channel estimation/equalization functions for DVB-T software-define receivers focusing on acquisition techniques, software optimization (real-time goal) and performance evaluation

Programming techniques for efficient and interoperable software defined radios

Recently, Software-Dened Radios (SDRs) has became a hot research topic in wireless communications eld. This is jointly due to the increasing request of reconfigurable and interoperable multi-standard radio systems able to learn from their surrounding environment and efficiently exploit the available frequency spectrum resources, so realizing the cognitive radio paradigm, and to the availability of reprogrammable hardware architectures providing the computing power necessary to meet the tight real-time constraints typical of the state-of-art wideband communications standards. Most SDR implementations are based on mixed architectures in which Field Programmable Gate Arrays (FPGA), Digital Signal Processors (DSP) and General Purpose Processors (GPP) coexist. GPP-based solutions, even if providing the highest level of flexibility, are typically avoided because of their computational inefficiency and power consumption. Starting from these assumptions, this thesis tries to jointly face two of the main important issues in GPP-based SDR systems: the computational efficiency and the interoperability capacity. In the first part, this thesis presents the potential of a novel programming technique, named Memory Acceleration (MA), in which the memory resources typical of GPP-based systems are used to assist central processor in executing real-time signal processing operations. This technique, belonging to the classical computer-science optimization techniques known as Space-Time trade-offs, defines novel algorithmic methods to assist developers in designing their software-defined signal processing algorithms. In order to show its applicability some "real-world" case studies are presented together with the acceleration factor obtained. In the second part of the thesis, the interoperability issue in SDR systems is also considered. Existing software architectures, like the Software Communications Architecture (SCA), abstract the hardware/software components of a radio communications chain using a middleware like CORBA for providing full portability and interoperability to the implemented chain, called waveform in the SCA parlance. This feature is paid in terms of computational overhead introduced by the software communications middleware and this is one of the reasons why GPP-based architecture are generally discarded also for the implementation of narrow-band SCA-compliant communications standards. In this thesis we briefly analyse SCA architecture and an open-source SCA-compliant framework, ie. OSSIE, and provide guidelines to enable component-based multithreading programming and CPU affinity in that framework. We also detail the implementation of a real-time SCA-compliant waveform developed inside this modified framework, i.e. the VHF analogue aeronautical communications transceiver. Finally, we provide the proof of how it is possible to implement an efficient and interoperable real-time wideband SCA-compliant waveform, i.e. the AeroMACS waveform, on a GPP-based architecture by merging the acceleration factor provided by MA technique and the interoperability feature ensured by SCA architecture

Persisting Meissner state and incommensurate phases of hard-core boson ladders in a flux

The phase diagram of a half-filled hard core boson two-leg ladder in a flux is investigated by means of numerical simulations based on the Density Matrix Renormalization Group (DMRG) algorithm and bosonization. We calculate experimentally accessible observables such as the momentum distribution, as well as rung current, density wave and bond-order wave correlation functions, allowing us to identify the Mott Meissner and Mott Vortex states. We follow the transition from commensurate Meissner to incommensurate Vortex state at increasing interchain hopping till the critical value [Piraud et al. Phys. Rev. B v. 91, p. 140406 (2015)] above which the Meissner state is stable at any flux. For flux close to $\pi$, and below the critical hopping, we observe the formation of a second incommensuration in the Mott Vortex state that could be detectable in current experiments.Comment: RevTeX 4, 5 pages + 8 pages supplemental, 6 EPS figures; (v2) references added, corrected the discussion of the Meissner state at high interchain hoppin

Incommensurate phases of a bosonic two-leg ladder under a flux

A boson two--leg ladder in the presence of a synthetic magnetic flux is investigated by means of bosonization techniques and Density Matrix Renormalization Group (DMRG). We follow the quantum phase transition from the commensurate Meissner to the incommensurate vortex phase with increasing flux at different fillings. When the applied flux is $\rho \pi$ and close to it, where $\rho$ is the filling per rung, we find a second incommensuration in the vortex state that affects physical observables such as the momentum distribution, the rung-rung correlation function and the spin-spin and charge-charge static structure factors.Comment: 19 pages, 9 EPS figures, RevTeX 4 (v1); 20 pages, 10 EPS figures, improved section on mean-field theory (v2

Achieving Large Multiplexing Gain in Distributed Antenna Systems via Cooperation with pCell Technology

In this paper we present pCellTM technology, the first commercial-grade wireless system that employs cooperation between distributed transceiver stations to create concurrent data links to multiple users in the same spectrum. First we analyze the per-user signal-to-interference-plus-noise ratio (SINR) employing a geometrical spatial channel model to define volumes in space of coherent signal around user antennas (or personal cells, i.e., pCells). Then we describe the system architecture consisting of a general-purpose-processor (GPP) based software-defined radio (SDR) wireless platform implementing a real-time LTE protocol stack to communicate with off-the-shelf LTE devices. Finally we present experimental results demonstrating up to 16 concurrent spatial channels for an aggregate average spectral efficiency of 59.3 bps/Hz in the downlink and 27.5 bps/Hz in the uplink, providing data rates of 200 Mbps downlink and 25 Mbps uplink in 5 MHz of TDD spectrum.Comment: IEEE Asilomar Conference on Signals, Systems, and Computers, Nov. 8-11th 2015, Pacific Grove, CA, US

Can You Activate Me? From Robots to Human Brain

L'efficacia dei robot sociali \ue8 stata ampiamente riconosciuta in diversi contesti della vita quotidiana degli umani, ma ancora poco si sa sulle aree cerebrali attivate osservando o interagendo con un robot. La ricerca che combina neuroscienze, scienze cognitive e robotica pu\uf2 fornire nuove intuizioni sia sul funzionamento del nostro cervello che sull'implementazione dei robot. Studi comportamentali sui robot sociali hanno dimostrato che la percezione sociale dei robot \ue8 influenzata da almeno due fattori: aspetto fisico e comportamento (Marchetti et al., 2018). Come possono le neuroscienze spiegare tali risultati? Ad oggi sono stati condotti studi attraverso l'utilizzo di tecniche sia EEG che fMRI per indagare le aree cerebrali coinvolte nell'interazione uomo-robot. Questi studi hanno affrontato principalmente le attivazioni cerebrali in risposta a paradigmi che coinvolgono o la performance di un'azione o la carica di una componente emotiva.The effectiveness of social robots has been widely recognized in different contexts of humans\u2019 daily life, but still little is known about the brain areas activated by observing or interacting with a robot. Research combining neuroscience, cognitive science and robotics can provide new insights into both the functioning of our brain and the implementation of robots. Behavioural studies on social robots have shown that the social perception of robots is influenced by at least two factors: physical appearance and behavior (Marchetti et al., 2018). How can neuroscience explain such findings? To date, studies have been conducted through the use of both EEG and fMRI techniques to investigate the brain areas involved in human-robot interaction. These studies have mainly addressed brain activations in response to paradigms involving either action performance or charged of an emotional component

Outline of a Theory of Scientific Aesthetics

I offer a theory of art that is based on science. I maintain that, as any other human activity, art can be studied with the tools of science. This does not mean that art is scientific, but aesthetics, the theory of art, can be formulated in accord with our scientific knowledge. I present elucidations of the concepts of aesthetic experience, art, work of art, artistic movement, and I discuss the ontological status of artworks from the point of view of scientific philosophy.Fil: Romero, Gustavo Esteban. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentin

Practice patterns and 90-day treatment-related morbidity in early-stage cervical cancer

To evaluate the impact of the Laparoscopic Approach to Cervical Cancer (LACC) Trial on patterns of care and surgery-related morbidity in early-stage cervical cancer