Optimal rate adaptation for energy efficiency with MQAM and MFSK

In this paper we analyse the energy efficiency of MQAM and MFSK for short range wireless transmissions, up to a few 100´s of meters, and propose optimum rate adaptation to minimize the energy dissipation during transmissions under different channel environment. Energy consumed for transmitting the data over a distance to maintain a prescribed error probability together with the circuit energy have been considered in our work. Our results indicate that the energy efficiency can be significantly improved by performing optimal rate adaptation given the radio and channel parameters, and furthermore we identify the maximum distance where optimal rate adaptation can be performed beyond which the optimum rate then becomes the same as the minimum data rate.