Prediction of Satellite Shadowing in Smart Cities with Application to IoT

The combination of satellite direct reception and terrestrial 5G infrastructure is essential to guarantee coverage in satellite based-Internet of Things, mainly in smart cities where buildings can cause high power losses. In this paper, we propose an accurate and fast graphical method for predicting the satellite coverage in urban areas and SatCom on-the-move scenarios. The aim is to provide information that could be useful in the IoT network planning process, e.g., in the decision of how many terrestrial repeaters are really needed and where they should be placed. Experiments show that the shadowed areas predicted by the method correspond almost perfectly with experimental data measured from an Eutelsat satellite in the urban area of Barcelona.Ministerio de Industria, Turismo y Comercio de España TSI-020301-2009-3

RAISE: A detailed routing algorithm for field-programmable gate arrays

This paper describes a new detailed routing algorithm, speciffically designed for those types of architecturesthat are found on the most recent generations of Field-Programmable Gate Arrays (FP-GAs). The algorithm, called RAISE, can be applied to a broad range of optimizations problems and has been used for detailed routing of symmetrical FPGAs, whose routing architecture consists of rows and columns of logic cells interconnected by routing channels. RAISE (Router using AadaptIve Simulated Evolution) searches not only for a possible solution, but tries to find the one with minimum delay. Excelent routing results have been obtained over a set of several benchmark circuits getting solutions close to the minimum number of tracks

DVB-T2: The Second Generation of Terrestrial Digital Video Broadcasting System

This paper provides a review of the second generation of terrestrial digital video broadcasting standard (DVB-T2). DVB-T2 is the evolution of DVB-T and, together with DVB-S2 and DVB-C2, inaugurated a new transition from the firstgeneration digital broadcasting systems, similar to the transition from analog-to-digital systems. In this paper, the most relevant features of DVB-T2 are explained in detail, along with their benefits and trade-offs. This paper also presents a comprehensive review of the laboratory and field trial results available so far. Especial emphasis is placed in the results of the measurements carried out to test the mobile reception and the novel technologies as multiple input single output and time frequency slicing.This work was supported in part by the University of the Basque Country UPV/EHU under Grant UFI 11/30, in part by the Basque Government under Grants IT-683-13 and SAIOTEK, and in part by the Spanish Ministry of Economy and Competitiveness Project HEDYT-GBB under Grant TEC2012-33302.Eizmendi, I.; Velez, M.; Gómez Barquero, D.; Morgade, J.; Baena Lecuyer, V.; Slimani, M.; Zoellner, J. (2014). DVB-T2: The Second Generation of Terrestrial Digital Video Broadcasting System. IEEE Transactions on Broadcasting. 60(2):258-271. https://doi.org/10.1109/TBC.2014.2312811S25827160

OFDM synchronization scheme for Power Line Telecommunications (PLT)

This paper presents a new scheme for OFDM time and frequency synchronization with application in Power Line Telecommunications (PLT). Simulation results show an excellent behavior, even for the low values of SNR in the synchronizer input inherent to PLT. The synchronizer has been prototyped on an FPGA prior to be integrated in the single-chip PLT system

Digital predistortion technique with in-band interference optimisation applied to DVB-T2

The efficient transmission and nonlinear modelling of orthogonal frequency division multiplexing (OFDM) signals are difficult to address owing to the special characteristics of this modulation scheme. Proposed is a digital predistortion technique suitable for the implementation in an OFDM transmitter to optimise the in-band interference caused by the nonlinear distortion generated in the amplification chain. The approach is experimentally validated by its application in one of the world's most advanced broadcasting systems, achieving an outstanding linearisation performance in the transmitter; specially for the in-band interference, a modulation error ratio (MER) of 42.1 dB is obtained.CICYT TEC2011-2355

Subsampling OFDM-based ultrasonic data communication through metallic channels for monitoring of cargo containers

An enhanced ultrasonic communication system based on piezoelectric transducers for monitoring of goods in cargo containers is presented. The proposed system consists of several sensors placed inside the container, whose data are collected and transmitted outside it. Data transmission is carried out by an ultrasonic communication channel, in order to avoid drilling the wall of the container. The proposed data communication system is based on the transmission of a 128-OFDM signal. This modulation has been chosen due to its robustness to channels with frequency-selective fading and its spectrum efficiency. In order to increase the signal bandwidth and to reduce the power consumption at the internal node (transmitter), the proposed system exploits the non-linearity of the metallic channel to transmit at higher resonance frequencies. Moreover, power consumption at the external node (receiver) is reduced by using a subsampling based receiver, which allows its implementation by low-cost electronics.This work was supported by the Spanish Ministry of Economy and Competitiveness under Projects TEC2016-80396-C2-2-R and TEC2016-80396-C2-1-

Microprocessor and FPGA interfaces for in-system co-debugging in field programmable hybrid systems

Modern trends in technology require efficient control and processing platforms based on connected software-hardware subsystems. Due to their complexity and size, algorithms implemented on these platforms are difficult to test and verify. When these types of solution are being designed, it is necessary to provide information of the internal values of registers and memories of both the software and hardware during the execution of the complete system. The final architecture of the targeted design and its debugging capabilities strongly depends on how the hybrid system is connected and clocked. This article discusses different architectural strategies that have been adopted for a hybrid hardware-software platform, built ready for debugging, and that uses components that can be easily found with a few special features. All the solutions have been implemented and evaluated using the UNSHADES-2 framework

Radiation environment emulation for VLSI designs: a low cost platform based on xilinx FPGA's

As technology shrinks, critical industral applications have to be designed with special care. VLSI circuits become more sensitive to ambient radiation: it affects to the internal structures, combinational or sequential elements. The effects, known as Single Event Effects (SEEs), are modeled as spontaneous logical changes in a running netlist. They can be mitigated at netlist design level by means of inserting massive redundancy logic in the IC memory elements, as well as designing robust deadlock-free state machines. Current techniques for the analysis and verification of the protection logic for VLSI are inefficient and expensive, lacking either speed or analysis. This paper presents the FT-UNSHADES system. This system is a low cost emulator focused on bit-flip insertion and SEE analysis at hardware speed, based on a Xilinx Virtex-II. Radiation tests are emulated in a highly controlled process, using a non-intrusive method. As a result the system can insert and analyse at least 80K faults per hour in a system with 2 million test vectors