Energy-aware ultrasonic communication through metal for wireless sensing applications

In the field of acoustic communication, there have been significant advances in recent years. These advances are mostly related to the progress and widespread deployment of software-defined radios. Yet, the energy demand of such systems is not suitable for long-term operation of battery-powered devices (e.g., wireless sensors) due to their limited energy resources at both the transmitter's and receiver's side. Therefore, in this contribution, we propose a half-duplex ultrasonic communication exploiting a differential phase shift keying. An implementation of a transceiver is realized on an ultra low-power micro controller communicating through a 1.6 mm thick metal plate. A demodulation rate of 173 kbps is achieved, consuming only 262 nJ/bit in transmitting mode and 420 nJ/bit in receiving mode at a preliminary bit error rate of 2 x 10(-5).