Banca de DEFESA: PEDRO THIAGO VALERIO DE SOUZA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : PEDRO THIAGO VALERIO DE SOUZA
DATA : 27/01/2017
HORA: 14:30
LOCAL: Auditório do LAMP
TÍTULO:

ANALYSIS OF WAVELET CODING IN RADIO SYSTEMS WITH DYNAMIC SPECTRUM ACCESS

PALAVRAS-CHAVES:

Software Defined Radio, Channel Coding, Wavelet Coding, Dynamic Spectrum Access,
Mobile Communication System, Spectral Sensing, Cognitive Radio, Cyclostationary Analysis,
Energy Sensing, Genetic Algorithms, Multiobjective Optimization

PÁGINAS: 112
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Elétrica
SUBÁREA: Telecomunicações
ESPECIALIDADE: Sistemas deTelecomunicações
RESUMO:

In mobile communications systems, signals propagate over multipaths over time-varying channels, subject to distortion caused by fading and Doppler shifts. In order to minimize such distortions, coding techniques and transmission diversity may be employed, such as Wavelet Encoding. This technique is based on the orthogonality of the wavelet matrix rows and has the capacity to generate diversity gains, increasing the robustness of the system to time-varying fading, without compromising the spectral efficiency of the system. In this work, the wavelet coding is investigated in scenarios of cognitive radio with dynamic spectrum access. These radio systems have been consolidating as a new paradigm of wireless communications with the advance of digital signal processing techniques. Cognitive radio systems with dynamic spectrum access should be able to perceive unoccupied frequency bands for opportunistic transmissions as well as detect the presence of primary users when they occupy their licensed spectrum. Therefore, a crucial element for the operation of cognitive radio systems encoded by wavelet coding is the ability to sense the signals encoded by this technique. As will be detailed, the possibility of sensing such signals is conditioned to a suitable design of the signal constellation used in the modulation of the coded symbols. In this work, the design of these constellations is done via genetic algorithms, using a multiobjective optimization approach. The developed system is evaluated for its robustness to time-varying plane fading through a bit error probability (BER) versus Eb/N0 analysis, and the possibility of spectral sensing of its signals via cyclostationary analysis and energy detection method. The results indicate the feasibility of the wavelet coding technique in radio scenarios with dynamic spectrum access, with good results of BER performance and sensed signal detection rates.

MEMBROS DA BANCA:
Presidente - 1543191 - LUIZ FELIPE DE QUEIROZ SILVEIRA
Interno - 347628 - ADRIAO DUARTE DORIA NETO
Interno - 1412682 - VICENTE ANGELO DE SOUSA JUNIOR
Externo à Instituição - EDMAR CANDEIA GURJÃO - UFCG