Radio Frequency IDentification (RFID) is a contactless, automatic identification wireless technology primarily used for identifying and tracking of objects, goods and humans. RFID is not only limited to identification and tracking applications. This proliferating wireless technology has been deployed in numerous securities sensitive applications e.g. access control, e-passports, contactless payments, driver license, transport ticking and health cards. RFID inherits all the security and privacy problems that are related to wireless technology and in addition to those that are specific to RFID systems. The security and privacy protection schemes proposed in literature for wireless devices are mostly secured through symmetric/asymmetric keys encryption/decryption and hash functions. The security of all these cryptographic algorithms depends on computationally complex problems that are hard to compute using available resources. However, these algorithms require cryptographic operations on RFID tags which contradict the low cost demand of RFID tags. Due to limited number of logic gates in tags, i.e., 5K-10K, these methods are not practical. Much research effort has done in attempt to solve consumer's privacy and security problem. Solutions that prevent clandestine inventory are mostly application layer techniques. To solve this problem, a new RFID physical layer scheme has been proposed namely Direct Sequence Backscatter Encryption (DSB Enc). The proposed scheme uses level generator to produce different levels before transmitting the signal to the tag. The tag response to the signal sent by the reader using backscatter communications on the same signal which looks random to the eavesdropper. Therefore eavesdropper cannot extract the information from reader to tag and tag to reader communication using passive eavesdropping. As reader knows the different generated levels added to the carrier signal, it can remove the levels and retrieve the tag's messages. We proposed a lightweight, low-cost and practically secure physical layer security to the RFID system, for a supply chain processing application, without increasing the computational power and tag's cost. The proposed scheme was validated by simulations on GNU Radio and experimentation using SDR and a WISP tag. Our implementation and experimental results validate that DSB Enc is secure against passive eavesdropping, replay and relay attacks. It provides better results in the presence of AWGN channel.

This thesis investigates the design and implementation of turbo codes over the GNU radio. The turbo codes is a class of iterative channel codes which demonstrates strong capability for error correction. A software defined radio (SDR) is a communication system which can implement different modulation schemes and tune to any frequency band by means of software that can control the programmable hardware. SDR utilizes the general purpose computer to perform certain signal processing techniques. We implement a turbo coding system using the Universal Software Radio Peripheral (USRP), a widely used SDR platform from Ettus. Detail configuration and performance comparison are also provided in this research.

In this thesis, we present the design and implementation of a CubeSat receiver system using the Universal Software Radio Peripheral (USRP) and GNU Radio. The goal of this project is to develop a low-cost and flexible ground station capable of receiving telemetry and payload data from CubeSats in real time. The CubeSat receiver operates in the UHF frequency range with a center frequency of 435 MHz and uses a software-defined radio (SDR) approach to provide wideband signal processing and demodulation capabilities. The satellite transceiver transmits an Ax.25 Transciever packet every 1 second using the Pumpkin CubeSat kit programmed in MPLab. To achieve this goal, we discuss the design considerations for the receiver system, including the selection of suitable hardware components and the development of custom software blocks in GNU Radio. We also developed the GFSK-based transmitter and receiver in GNU Radio, as well as a tracking system for the satellite. To decode the Ax.25 radio packet transmitted by the Pumpkin CubeSat kit, we developed an Ax.25 deframer in GNU Radio to decode the received signal. Our results demonstrate that the CubeSat receiver is capable of receiving and demodulating AX.25 formatted radio signals from Transciever. Additionally, we show that the receiver system is scalable and can be easily adapted for use with other CubeSat missions. Overall, our work provides a practical solution for CubeSat communication and lays the groundwork for future developments in low-cost CubeSat ground station technology.

The goal of software-defined radio (SDR) is to move the processing of radio signals from the analog domain to the digital domain — to use digital microchips instead of analog circuit components. Until faster, higher-precision analog-to-digital (ADCs) and digital-to-analog converters (DACs) become affordable, however, some analog signal processing will be necessary. We still need to convert high-radio frequency (RF) signals that we receive to low intermediate-frequency (IF) or baseband (centered on zero Hz) signals in order for ADCs to sample them and feed them into microchips for processing. The reverse is true when we transmit. Amplification is also needed on the receive side to fully utilize the dynamic range of the ADC and power amplification is needed on the transmit side to increase the power output from the DAC for transmission. Analog filtering is also needed to avoid saturating the ADC or to filter out interference when receiving and to avoid transmitting spurs. The analog frequency conversion, amplification and filtering section of a radio is called the RF front end. This thesis describes work on a new RF front end daughterboard for the Universal Software Radio Peripheral, or USRP. The USRP is a software-radio hardware platform designed to be used with the GNU Radio software radio software package. Using the Motorola RFIC4 chip, the new daughterboard receives RF signals, converts them to baseband and does analog filtering and amplification before feeding the signal into the USRP for processing. The chip also takes transmit signals from the USRP, converts them from baseband to RF and amplifies and filters them. The board was designed and laid out by Randall Nealy. I wrote the software driver for GNU Radio. The driver defines the interface between the USRP and the RFIC chip, controls the physical settings, and calculates and sets the hundreds of variables necessary to operate this extremely complex chip correctly. It allows plug-and-play compatibility with the current USRP daughterboards and supplies additional functions not available in any other daughterboard. / Master of Science

The work deals with the use of software-defined radio as a probe for monitoring the operation of wireless communication according to the IEEE 802.11a/g standard. In the theoretical introduction, the concept of software-defined radio as a hardware device with software programmable circuits enabling the transmission or reception of signals in theoretically any frequency band is introduced. The introduction also contains adescription of selected devices and the IEEE 802.11 protocol with its most used additionsand modulations. In the first part of the practical part of the work, wireless communication is capturedusing a wireless network card in monitoring mode. The intercepted communication was decrypted and this decrypted traffic was compared with the data captured by the probe within the network. These results then served as acomparative basis for software-defined radio capturing. The focus of this work is to verify the capabilities of software-defined radio and its use for sniffing wireless communicationin the frequency band 2.4 GHz and 5 GHz. The attempt to use a software-defined radio here results from the scalability and adaptability that a wireless card cannot offer due to fixed hardware parameters. LimeSDR mini, LimeSDR and bladeRF 2.0 devices were used for capture. First, the configuration of the operating system, the installation of drivers and programs for control and work with selected devices are described. After verifying the functionality of the software-defined radio, a model of a signal decoder with the parameters of the IEEE 802.11g standard captured from the radio spectrum was put into operation. Finally, the data streams captured by the software-defined radio and the wireless network card were compared side by side. The results showed that the software-defined radio in the used configuration captures only a part of the total volume of transmitted frames.

In wireless communication systems, one of the most important resources being focused on all the researchers is spectrum. A cognitive radio (CR) system is one of the efficient ways to access the radio spectrum opportunistically, and efficiently use the available underutilized licensed spectrum. Spectrum utilization can be significantly enhanced by developing more applications with adopting CR technology. CR systems are implemented using a radio technology called software-defined radios (SDR). SDR provides a flexible and cost-effective solution to fulfil the requirements of end users. We can see a lot of innovations in Internet of Things (IoT) and increasing number of smart devices. Hence, a CR system application involving an IoT device is studied in this thesis. Opportunistic spectrum access involves two tasks of CR system: spectrum sensing and dynamic spectrum access. The functioning of the CR system is rest upon the spectrum sensing. There are different spectrum sensing techniques used to detect the spectrum holes and a few of them are discussed here in this thesis. The simplest and easiest to implement energy detection spectrum sensing technique is used here to implement the CR system. Dynamic spectrum access involves different models and strategies to access the spectrum. Amongst the available models, an interweave model is more challenging and is used in this thesis. Interweave model needs effective spectrum sensing before accessing the spectrum opportunistically. The system designed and simulated in this thesis is capable of transmitting an output from an IoT device using USRP and GNU radio through accessing the radio spectrum opportunistically.

[pt] Nesta tese de doutorado foi investigado, por meio de simulações computacionais e em laboratório utilizando Matlab, GNU Radio e GNU Radio Companion (GRC), o desempenho de redes de Rádio Cognitivo com sensoriamento individual (SS) e com sensoriamento cooperativo (CSS) do espectro considerando o algoritmo não paramétrico de detecção de energia e diferentes abordagens deste método de detecção. Foi também implementado um cenário de medição em tempo real usando os equipamentos de rádio definido por software (SDR por suas siglas em inglês) conhecidos como Universal Software Radio Peripheral (USRP). Os cenários de medição consideram a cooperação, baseada na utilização de regras de fusão de dados do tipo hard, no sensoriamento local de sinais de TV Digital por usuários cognitivos não licenciados. A principal contribuição desta tese de doutorado baseia-se na formulação do método de energia combinando os conceitos da teoria clássica do sensoriamento de espectro das redes de Rádio Cognitivo, tanto com sensoriamento individual (SS) como sensoriamento cooperativo (CSS) de espectro, com um cenário de implementação em laboratório levando em conta os requisitos, parâmetros técnicos e de operação do equipamento de medição SDR. / [en] This PhD thesis investigate the performance of cognitive radio networks with single sensing (SS) and cooperative spectrum sensing (CSS) networks through computational and laboratory simulations using Matlab, GNU Radio and the GNU Radio Companion (GRC) computational radio software, considering the non-parametric energy detection method and different approaches to this method. The implementation also includes a real-time measurement testbed scenario using Software Defined Radio (SDR) equipment, known as Universal Software Radio Peripheral (USRP). The measurement scenarios consider the cooperative local sensing of the digital TV by non-licensed cognitive radio users, based on hard fusion rules. The main contribution of this doctoral thesis is based on the formulation of the energy detection method combining the concepts of the classical theory of the spectrum sensing of Cognitive Radio networks, with both individual sensing (SS) and cooperative spectrum sensing (CSS), in a laboratory implementation scenario according to the requirements, technical parameters and operation of the SDR measuring equipment.

There has recently been growing interest in using physical layer network coding techniques to facilitate information transfer in wireless relay networks. The physical layer network coding technique takes advantage of the additive nature of wireless signals by allowing two terminals to transmit simultaneously to the relay node. This technique has several performance benefits, such as improving utilization and throughput of wireless channels and reducing delay. In this thesis, we present an algorithm for joint decoding of two unsynchronized transmitters to a modulo-2 sum of their transmitted messages. We address the problems that arise when the boundaries of the signals do not align with each other and when their phases are not identical. Our approach uses a state-based Viterbi decoding scheme that takes into account the timing offsets between the interfering signals. As a future research plan, we plan to utilize software-defined radios (SDRs) as a testbed to show the practicality of our approach and to verify its performance. Our simulation studies show that the decoder performs well with the only degrading factor being the noise level in the channel.

This thesis deals with a design of telemetry archive of PSAT, PSAT-2 and BRICSat sattelites. This telemetry data need to be extracted from SDR IQ records. The thesis contains a Doppler effect theory and description of structure of telemetry data. Then it presents a design of a program for Doppler effect correction, demodulation and decoding of these records and saving the data to telemetry archive. Thesis also deals with analysis of decoded data.

Submitted by Marta Toyoda (1144061@mackenzie.br) on 2018-03-09T16:59:58Z No. of bitstreams: 2 GUILHERME BOSCOLO DOS SANTOS.pdf: 18400225 bytes, checksum: 47dbfd4bd3d74984f6d4c7bfff9e594d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Paola Damato (repositorio@mackenzie.br) on 2018-04-04T11:41:38Z (GMT) No. of bitstreams: 2 GUILHERME BOSCOLO DOS SANTOS.pdf: 18400225 bytes, checksum: 47dbfd4bd3d74984f6d4c7bfff9e594d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-04T11:41:38Z (GMT). No. of bitstreams: 2 GUILHERME BOSCOLO DOS SANTOS.pdf: 18400225 bytes, checksum: 47dbfd4bd3d74984f6d4c7bfff9e594d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-01-30 / With the establishment of digital television technology, improvements have emerged com- pared to analogue, such as bringing users better quality picture and video. This transition of the analogue/digital system is already a reality in Brazil, so that organs linked to the Brazilian government are performing the process of switch-off the analogue signal. This switch-off aims to release the electromagnetic spectrum in the UHF band to allow the expansion of mobile broadband. Due to this operation in adjacent bands, there is a pos- sibility that the LTE signal interferes with digital TV. Studies presented by researchers report that antennas designed with ”smart” characteristics can reduce interference from unwanted signals. When designed with dual polarization, such antennas enable the wireless link to become more robust due to differences polarization existing between the transmitter and the receiver of the current communications systems. This essay presents a new pro- posal of dual-polarized antenna, whose operating is destined to the radio frequency range of the digital television after the switch-off, so that it can be used in the current digital te- levision standard as in the next-generation of digital broadcasting. The proposed antenna was designed with a full wave electromagnetic field simulator. A prototype was simulated and built and experimental results showed that the proposed antenna could cover a band of 384 MHz in the UHF band and 40 MHz in the high VHF band as well as serving as a filter for the LTE band. Tests were performed using software defined radio and showed their reception quality. / Com o estabelecimento da tecnologia da televisão digital, melhorias surgiram comparadas com à analógica, como levar aos usuários uma melhor qualidade de imagem e vídeo. Essa transição do sistema analógico/digital já é uma realidade no Brasil, de modo que órgãos ligados ao governo brasileiro já estão realizando o processo de desligamento do sinal analógico. Esse desligamento que tem por objetivo liberar o espectro eletromagnético na faixa de UHF para permitir a expansão da banda larga móvel. Devido a esta operação em faixas adjacentes, existe a possibilidade do sinal LTE interferir na TV digital. Estudos apresentados por pesquisadores relatam que antenas projetadas com características de “inteligentes” podem reduzir interferências vindas de sinais indesejáveis. Quando projetadas com dupla polarização, tais antenas ainda possibilitam que o enlace sem fio se torne mais robusto frente às diferenças de polarização existentes entre o transmissor e o receptor dos sistemas de comunicações atuais. Esta pesquisa apresenta uma nova proposta de antena com dupla polarização, cuja faixa de operação é destinada a faixa de radiofrequência da televisão digital após o desligamento do sinal analógico, de forma a ser utilizada no atual sistema de televisão como em sua próxima geração. A antena proposta foi projetada com simulador de campo eletromagnético de onda completa. Um protótipo foi simulado e construído e os resultados experimentais demonstraram que a antena proposta pode cobrir uma banda de 384 MHz na faixa do UHF e 40 MHz na de VHF alto além de servir como filtro para a faixa do LTE. Testes foram realizados utilizando rádio definidos por software e mostraram sua qualidade de recepção.