Aim of this work is design and implementation of error detection and correction tool for UDF filesystem for GNU/Linux.

Tato diplomová práce vznikla za podpory ANF DATA s.r.o., Brno. Diplomová práce je vypracována v angličtině. Vstupní bariéra pro vývoj uvnitř GCC se během posledních let znatelně snížila. Na konferencích, v časopisech a na webu se objevují články s architektonickými přehledy a návody. Věci se nadále zjednodušují použitím oficiálního vnitřního jazyka GENERIC: Pro komunikaci mezi přední částí a zbytkem překladače již není nutné zabývat se obtížným a nepřehledným RTL. Přesto je práce se souborem zdrojových kódů velikosti GCC nutně složitá. Je třeba napsat určité soubory a provést určitá nastavení, oboje jen s poměrně malým množstvím dokumentace. Cílem této práce je pomoci s posledním zmíněným bodem. Práce popisuje ukázkovou přední část: Vše od vytvoření zdrojových souborů, přes různé konstrukce jazyka GENERIC, až k problémům s kompilací běhové podpory nebo používání nativního preprocesoru.

Recent disasters, including the 9/11 terrorist attacks, Hurricane Katrina, the London subway bombings, and the California wildfires, have all highlighted the limitations of current mobile communication systems for public safety first responders. First, in a point-to-point configuration, legacy radio systems used by first responders from differing agencies are often made by competing manufacturers and may use incompatible waveforms or channels. In addition, first responder radio systems, which may be licensed and programmed to operate in frequency bands allocated within their home jurisdiction, may be neither licensed nor available in forward-deployed disaster response locations, resulting in an operational scarcity of usable frequencies. To address these problems, first responders need smart radio solutions which can bridge these disparate legacy radio systems together, can incorporate new smart radio solutions, or can replace these existing aging radios. These smart radios need to quickly find each other and adhere to spectrum usage and access policies. Second, in an infrastructure configuration, legacy radio systems may not operate at all if the existing communications backbone has been destroyed by the disaster event. A communication system which can provide a new, temporary infrastructure or can extend an existing infrastructure into a shaded region is needed. Smart radio nodes that make up the public safety infrastructure again must be able to find each other, adhere to spectrum usage policies, and provide access to other smart radios and legacy public safety radios within their coverage area. This work addresses these communications problems in the following ways. First, it applies cognitive radio technology to develop a smart radio system capable of rapidly adapting itself so it can communicate with existing legacy radio systems or other smart radios using a variety of standard and customized waveforms. These smart radios can also assemble themselves into an ad-hoc network capable of providing a temporary communications backbone within the disaster area, or a network extension to a shaded communications area. Second, this work analyzes and characterizes a series of rendezvous protocols which enable the smart radios to rapidly find each other within a particular coverage area. Third, this work develops a spectrum sharing protocol that enables the smart radios to adhere to spectral policies by sharing spectrum with other primary users of the band. Fourth, the performance of the smart radio architecture, as well as the performance of the rendezvous and spectrum sharing protocols, is evaluated on a smart radio network testbed, which has been assembled in a laboratory setting. Results are compared, when applicable, to existing radio systems and protocols. Finally, this work concludes by briefly discussing how the smart radio technologies developed in this dissertation could be combined to form a public safety communications architecture, applicable to the FCC's stated intent for the 700 MHz Band. In the future, this work will be extended to applications outside of the public safety community, specifically, to communications problems faced by warfighters in the military. / Ph. D.

Software Defined Radios (SDRs) lend themselves to flexibility and extensibility because they<br />depend on software to implement radio functionality. Cognitive Engines (CEs) introduce<br />intelligence to radio by monitoring radio performance through a set of meters and configuring<br />the underlying radio design by modifying its knobs. In Cognitive Radio (CR) applications,<br />CEs intelligently monitor radio performance and reconfigure them to meet it application<br />and RF channel needs. While the issue of introducing computational knobs and meters<br />is mentioned in literature, there has been little work on the practical issues involved in<br />introducing such computational radio controls.<br /><br />This dissertation decomposes the radio definition to reactive models for the CE domain<br />and real-time, or dataflow models, for the SDR domain. By allowing such design space<br />decomposition, CEs are able to define implementation independent radio graphs and rely on<br />a model transformation layer to transform reactive radio models to real-time radio models<br />for implementation. The definition of knobs and meters in the CE domain is based on<br />properties of the dataflow models used in implementing SDRs. A framework for developing<br />this work is presented, and proof of concept radio applications are discussed to demonstrate<br />how CEs can gain insight into computational aspects of their radio implementation during<br />their reconfiguration decision process.<br /> / Ph. D.

With interoperability issues plaguing emergency responders throughout the country, Cognitive Radio (CR) offers a unique solution to streamline communication between police, Emergency Medical Technicians (EMT), and military officers. Using Software Defined Radio (SDR) technology, a flexible radio platform can be potentially configured using a Cognitive Engine (CE) to transmit and receive many different incompatible radio standards. In this thesis, an interface between a Cognitive Engine and an SDR platform is described which modifies (i.e., configures) the radio's operation. The interface is based upon communicating information via eXtensible Markup Language (XML) data files that contain the radio's Physical (PHY) parameters. The XML data files have been designed such that more development can be made to its structure as this research develops. The GNU Radio and the Universal Software Radio Peripheral (USRP) serve as the SDR platform for an example implementation. The example implementation involves importing XML data files into the SDR for quick configuration. Three configuration examples are used to describe this process. / Master of Science

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The thesis work shows the implementation of sensing and communication, so a basic knowledge of analog and digital communication systems is needed to understand this paper Background. With the increase in smart devices, the bandwidth requirements are increased, which created congestion in the radio spectrum resources. To overcome this spectrum congestion, Integrated Sensing and Communication (ISAC) can be used. This can be achieved by using Orthogonal Frequency-Division Multiplexing (OFDM) signals. In ISAC, both sensing and communication use the same resources,which in turn predominantly improves the efficiency of the spectrum resources usage and reduces the cost of hardware. Objectives. The main aim of this research is to integrate radar sensing and communication using Software Defined Radios (SDR) and GNU Radio. The goal is to design a signal waveform and a receiver algorithm supporting both sensing and communications and then carry out experiments on an SDR unit to evaluate the functionality and performance. Methods. Experimentation is used in this research and is conducted at Ericsson Research Laboratory. The experiment is divided into three major parts. First, to test the sensing functionalities using Frequency Modulated Continuous Waves (FMCW). Second, to test the communication functionalities using OFDM signals. Third, to design the receiver algorithm and signal waveform for ISAC. To verify the dual functional paradigm, the results from the ISAC are compared with the individual test results of sensing and communications using FMCW and OFDM signals. Results. A receiver algorithm is designed to calculate the sensing range and BER of ISAC using an SDR. The results show the possibility of implementing ISAC using OFDM in GNU Radio with SDR. The thesis project can also be viewed as a proof of concept for ISAC on SDR, helping in providing useful information related to radar sensing and communication using OFDM and performance evaluation. Conclusions. The experimental results show the dual-functional waveform for ISAC, helping in the evolution of 5G and beyond 5G communication systems. The identified drawbacks can be used by future researchers working on advanced 5G mobile communication systems to develop more efficient systems. Keywords: Communications, FMCW, GNU Radio, ISAC, OFDM, SDR, Sensing.

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