Energy and spectrum trade-off for uncoded MQAM in energy constrained system
Résumé
The energy consumption of wireless communicating
devices as well as their autonomy are two important factors in
energy constrained system such as Wireless Sensor Networks
(WSNs). The spectral efficiency is another important metric.
The main goal is to study the trade-off between the energy
consumption of the system and it’s spectral efficiency when varying
system parameters. In this paper, an uncoded system using
M-ary Quadrature Amplitude Modulation (MQAM) in which
the spectral efficiency is assumed proportional to its bandwidth
efficiency is used. In order to find the balance between spectral
and energy requirements, the considered system parameters are
studied. First, a general and comprehensive power model for
both transmitter and receiver is developed. Next, by considering
Additive White Gaussian Noise (AWGN) channel for point-topoint
communication, the total energy consumption is evaluated.
A new approximation for the Bit Error Rate (BER) is adopted.
Then, the effects of communication distance and the bandwidth
on the optimum spectral efficiency are studied. For a fixed BER,
we demonstrate that for each of those parameters, an optimum
energy to spectral-efficiency tradeoff can be found.