masterThesis
Desenvolvimento de uma codificação wavelet adaptativa para um sistema de controle sobre canais sem fio
Fecha
2017-01-30Registro en:
GAMA, Felipe Oliveira Simões. Desenvolvimento de uma codificação wavelet adaptativa para um sistema de controle sobre canais sem fio. 2017. 84f. Dissertação (Mestrado em Engenharia Elétrica e de Computação) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2017.
Autor
Gama, Felipe Oliveira Simões
Resumen
Wireless control systems have the capacity of sensing, control and actuation on the
information exchanged between the wireless sensor nodes in a control loop. However,
the exchanged information becomes susceptible to the degenerative effects produced by
the multipath propagation. In order to minimize the destructive effects characteristic of
wireless channels, several techniques have been investigated recently. Among them, the
wavelet coding is a good alternative for the wireless communications by their robustness
to the effects of the multipath and by its low computational complexity. This work proposes
an adaptive wavelet coding whose parameters of code rate and signal constellation can
vary according to the fading level, and evaluate the use of this transmission system in a
control loop implemented by wireless sensor nodes. The performance of the adaptive system
was evaluated in terms of bit error rate (BER) versus Eb=N0 and spectral efficiency,
considering a time-varying channel with flat Rayleigh fading, and in terms of processing
overhead on a control system with wireless communication. The results obtained through
computational simulations and experimental tests show the efficiency of the insertion of
the adaptive wavelet coding in a control loop with nodes interconnected by wireless link.
These results enable the use of this technique in a wireless link control mesh, bringing it
one step even closer to being applied in a practical control system.