How to choose the ADC resolution for short range low power communication?

We consider the maximization of the energy efficiency when communicating over a noisy single-input single-output channel, taking into account the transmit power as well as the power consumption of the analog-to-digital converter (ADC). This analysis is of interest in the context of energy constrained short range communication where low power, low cost and small size are key requirements (e.g. standard IEEE 802.15.4). In fact, the transmit power in such applications become smaller and reaches values in the order of the conversion or the processing power. Using an appropriate information-theoretic framework we show that the analog-to-digital converters (ADCs) for short range communication should be low-resolution, in order to reduce the overall power consumption. In addition we derive the optimal operating bit-resolution and signal-to-noise ratio (SNR) as function of the path-loss (i.e. the communication distance).