On the Energy Efficiency and Effective Throughput Tradeoff of Fading Channels

This paper investigates the tradeoff between the energy efficiency (EE) and the effective throughput (ET) of fading channels. In particular, we consider the case of zero channel state information (CSI) at the transmitter, and thus, the receiver can only successfully decode the source messages with certain probability. Accordingly, the ET, which is defined as the rate of the successfully decoded information, is adopted to measure the spectrum efficiency of the considered channels. We characterize the EE-ET region by exploiting its structure, and each boundary point is obtained by solving a quasi-concave problem. As a special case, we also obtain the maximum ET per unit energy in closed form. Finally, we generalize our results to the case of multihop relay channels.