Variable word length coding for energy-aware signal transmission

This paper presents an energy-efficient method for data transmission through improved data compression, based on the Walsh transform. The research is motivated by the need for optimal service life of wireless sensor networks, where individual sensor nodes are constrained by limited energy resources. A method of dynamically scaling sensor signals utilizing Walsh functions for data compression is presented. Theoretical background of the method is introduced, and its effectiveness is established through experimental study of electro-cardiogram (ECG) and bearing vibration signals. Results indicate that the method enables significant saving in the energy expenditure during wireless signal transmission.