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Rekonfigurovatelný generátor 5G NR signálů na RFSoC FPGA
Indrák, Dominik ; Gazda, Juraj (oponent) ; Maršálek, Roman (vedoucí práce)
Práce se zabývá simulací základní struktury OFDM modulátoru a demodulátoru připravovaného standardu 5G NR. V prostředí MATLAB jsou simulovány základní bloky jako je modulace, vkládání referenčních signálů, Fourierova transformace, vkládání cyklického prefixu, AWGN a vícecestné šíření. V práci je navržen způsob implementace modulátoru a demodulátoru do RFSoC kitu a jeho konfigurace. S využitím platformy STEMLab RedPitaya je implementován navržený generátor. V programu Matlab je generován 5G OFDM signál určený k vysílání. Přijatý signál je pak vyhodnocován opět v programu Matlab.
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Software-defined radio OFDM frame generation according to IEEE 802.22
Honek, Marek ; Gazda, Juraj (oponent) ; Maršálek, Roman (vedoucí práce)
This thesis proposes a new radio transmission protocol AWRAN for access to the amateur radio network HAMNET that does not require LOS to the access point. Furthermore, the thesis documents and discusses the prototypical implementation of simplified frames of this protocol on SDR and the test apparatus used for this purpose. The first chapter introduces the IEEE 802.22 WRAN standard on which AWRAN is based. Terms such as OFDM and OFDMA are described, as well as their advantages and applications. There are described the modulation techniques PSK and QAM, channel coding for error detection and correction, and the sources of these errors. The second chapter gives a detailed description of the parameters of the proposed AWRAN protocol. OFDM parameters, frame and superframe structures are described. The method of co-existence of multiple AWRAN cells and the exact form of the fourteen control messages that allow efficient allocation of bandwidth resources among up to four base stations and up to 63 users connected to each of these stations are described. The third section describes the structure of the simplified frame that was implemented on the RPX-100 testbed. It also describes the apparatus itself and its basic hardware building blocks as well as the software library that was used to implement the simplified frame. This chapter also describes the prepared test link and the theoretical calculation of the attenuation of this link. The fourth chapter deals with the programs that were developed as part of this work. Two of them were done for a first introduction to the hardware and software libraries. Another program serves as a generator of the previously described simplified frames, which are sent using SDR. The same program could be used as well as the receiver of these frames. The last program prepared performs a simulation of the wireless transmission using a mathematical model of the channel. It calculates the dependence of BER on SNR for the simulated transmission. The last section lists the functions that were defined and used in programs from the previous section.
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Frontend Impairments and Interference Compensation in FDM Systems
Harvánek, Michal ; Wang, Yide (oponent) ; Gazda,, Juraj (oponent) ; Maršálek, Roman (vedoucí práce)
The out-of-band (OOB) performance of advanced, filter-based multicarrier waveforms can easily be deteriorated by the nonlinearity of Power Amplifier (PA). One of the common ways to eliminate such signal quality degradation is a Digital PreDistortion (DPD) applied in the transmitter. The introductory part of the thesis presents the study of the impact of selected transceiver imperfections on the performance of DPD linearizers. Starting from the PA model identification based on the data captured using the low-cost Software Defined Radio (SDR) platform, we evaluate the performance in terms of OOB signal emissions at the PA output for the case of typical representatives of frequency-localized multicarrier signals. We highlight the fact that frontend imperfections can significantly affect the performance of predistorters. Interference between users in adjacent channels negatively affects the achievable throughput of mobile networks. The complexity of DPD implementation is sometimes a showstopper for its implementation in mobile terminals, and the OOB radiation generated by nonlinearity could result in serious problems. Thus, the core of the thesis deals with the receiver-side cancellation of interference caused by a nonlinear PA. The proposed interference cancellation method subtracts the OOB emissions from the received signal. In contrast to the state-of-the-art approaches, our method employs over-the-air estimation of PA model parameters together with a particular frequency domain filtering method that allows to generate the required training data. As an exemplary waveform, we use a Generalized Frequency Division Multiplex (GFDM), and we also evaluate the method on the SDR-based test-bed.
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Software-defined radio OFDM frame generation according to IEEE 802.22
Honek, Marek ; Gazda, Juraj (oponent) ; Maršálek, Roman (vedoucí práce)
This thesis proposes a new radio transmission protocol AWRAN for access to the amateur radio network HAMNET that does not require LOS to the access point. Furthermore, the thesis documents and discusses the prototypical implementation of simplified frames of this protocol on SDR and the test apparatus used for this purpose. The first chapter introduces the IEEE 802.22 WRAN standard on which AWRAN is based. Terms such as OFDM and OFDMA are described, as well as their advantages and applications. There are described the modulation techniques PSK and QAM, channel coding for error detection and correction, and the sources of these errors. The second chapter gives a detailed description of the parameters of the proposed AWRAN protocol. OFDM parameters, frame and superframe structures are described. The method of co-existence of multiple AWRAN cells and the exact form of the fourteen control messages that allow efficient allocation of bandwidth resources among up to four base stations and up to 63 users connected to each of these stations are described. The third section describes the structure of the simplified frame that was implemented on the RPX-100 testbed. It also describes the apparatus itself and its basic hardware building blocks as well as the software library that was used to implement the simplified frame. This chapter also describes the prepared test link and the theoretical calculation of the attenuation of this link. The fourth chapter deals with the programs that were developed as part of this work. Two of them were done for a first introduction to the hardware and software libraries. Another program serves as a generator of the previously described simplified frames, which are sent using SDR. The same program could be used as well as the receiver of these frames. The last program prepared performs a simulation of the wireless transmission using a mathematical model of the channel. It calculates the dependence of BER on SNR for the simulated transmission. The last section lists the functions that were defined and used in programs from the previous section.
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Rekonfigurovatelný generátor 5G NR signálů na RFSoC FPGA
Indrák, Dominik ; Gazda, Juraj (oponent) ; Maršálek, Roman (vedoucí práce)
Práce se zabývá simulací základní struktury OFDM modulátoru a demodulátoru připravovaného standardu 5G NR. V prostředí MATLAB jsou simulovány základní bloky jako je modulace, vkládání referenčních signálů, Fourierova transformace, vkládání cyklického prefixu, AWGN a vícecestné šíření. V práci je navržen způsob implementace modulátoru a demodulátoru do RFSoC kitu a jeho konfigurace. S využitím platformy STEMLab RedPitaya je implementován navržený generátor. V programu Matlab je generován 5G OFDM signál určený k vysílání. Přijatý signál je pak vyhodnocován opět v programu Matlab.
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