Modulation scaling for energy efficiency

Journées scientifiques 2016 URSI France : Énergie et Radiosciences, 15-16 mars 2016, Cesson-Sévigné (35), FranceThe energy consumption of wireless communicating devices as well as their autonomy are two importantfactors in energy constrained system such asWireless Sensor Networks (WSNs). The spectral efficiency is another importantmetric. The main goal is to study the trade-off between the energy consumption of the systemand it’s spectral efficiencywhen varying system parameters. In this paper, an uncoded system using M-ary Quadrature Amplitude Modulation(M-QAM) in which the spectral efficiency is assumed proportional to its bandwidth efficiency is used. In order to findthe balance between spectral and energy requirements, the considered system parameters are studied. First, a generaland comprehensive power model for both transmitter and receiver is developed. Next, by considering Additive WhiteGaussian Noise (AWGN) channel for point-to-point communication, the total energy consumption is evaluated. A newapproximation for the Bit Error Rate (BER) is adopted. Then, the effect of communication distance, bandwidth and circuitpower consumption on the optimum spectral efficiency is studied. For a fixed BER, we demonstrate that for each of thoseparameters, an optimumspectral efficiency can be found