Tese de Doutorado
O Programa de Pós-Graduação em Microeletrônica – PGMICRO, da Universidade Federal do Rio Grande do Sul, tem a satisfação de convidar a Comunidade Universitária para assistir à defesa pública de Tese de Doutorado do aluno LEANDRO AVILA DE AVILA realizar-se:
Data: 18/04/2019 às 09h:30min
Local: Instituto de Informática 43412(65) – sala 218
Título: “Cross-Layer Energy Model of IR-UWB for Short-Range Communication Systems ”
Orientador: Prof. Dr. SERGIO BAMPI
Prof. Dr. Eric E. Fabris(CEITEC e PGMICRO)
Prof. Dr. Fernando Paixão Cortes (CEITEC S.A.)
Prof. Dr. Edison Pignaton de Freitas (INF/UFRGS)
Short-range data communications and microelectronics circuits design are distinct and important fields of knowledge and there are few points of convergence between them in academic research. In the academic literature of each field there are few inter-related works and it is sparse the cross-referencing between them. All equipment for communication systems uses integrated circuit (ICs), which indicates a key connection between these engineering fields. The Open System Interconnection reference model is devoted to describe the abstraction levels in layers with their components, known as OSI layers. The power profiles of the first and second levels (PHY and MAC) for data communication are among the main concerns of this work. The PHY level is associated with the hardware (microelectronic devices included), and the MAC concentrates the low-level strategies to control the medium access. The energy of the whole system can be minimized by performing direct control on the PHY and MAC layers and, in this sense, the interplay between them constitutes a cross-layer model. At the PHY level, where the integrated circuits design contributes with gains when the investigation of architectures, circuits,and devices produce better hardware performance, specific tools are used to reach power reduction, representing a partial optimization of the model. At the MAC level, other aspects impact energy consumption and need to be assessed – for example, the duty cycle and algorithms to deal with fails in the communication process. In this work, the context where the data communication is employed is based on IEEE 802.15.6 standard, for wireless body area networks (WBANs). This work focuses mainly on the logic design of the forward error correction (FEC) coding and decoding hardware. The CODECs are embedded inside the transceivers, and these transceivers can be part of the nodes of a wireless sensor network. This research addresses the energy consumption model involving these modules. At the PHY level, the electrical UWB waveforms generated by the TX is also analyzed for better energy efficiency. This thesis covers three design aspects of the communication systems, which adheres to the 802.15.6 standard, and are at different layers, modeling the energy required in a cross-layer view. Namely, these aspects are: the way by which Ultra-Wideband (UWB) communication takes place with impulse modulation over the 3.1 GHz – 10.6 GHz bands, the relationship of the analytic equations of the energetic model concerning also the link budget, and the low-power hardware comparison, focusing on the FEC decoding hardware that was designed in this thesis. The contributions of the research include i) the pulse-shaping and modulation analysis, with a PPM modulation,with 3 or more bit, using PSWF pulses for higher spectral and energy efficiencies; ii) the BCH FEC decoder, designed in CMOS VLSI, with demonstrated advantages over the QC-LDPC, as the latter consumes 3.76 times more power for similar coding and data rates; iii) the improvement of the cross-layer energy efficiency model for IR-UWB, and its simulation in the operating scenario with multiple nodes that adhere to the IEEE standard 802.15.6.
Keywords: WBAN, Ultra-wide Band – UWB, IR-UWB, Cross-Layer Energy Model, Energy Efficiency, CMOS Digital Design.