On using BOC modulation in ultra-low power sensor networks for wildlife tracking

Localization and tracking of small animals in the wild using sensor networks require nodes with ultra-low power consumption, which are particularly challenging to design. Here, we target the tracking of bats in their natural habitat and have to limit the weight of the mote to 2g. To optimize the energy consumption in this scenario, the combination of data communication and ranging is essential. The limitations of the platform and the specific use case ask for a dedicated signal design. We start exploring the use of Binary Offset Carrier (BOC), which is known to be well suited for localization. In this paper, we concentrate on the data communication part of the system. We develop a BOC transceiver in Software Defined Radio (SDR) and perform simulations as well as lab measurements to evaluate its performance and compare it to Binary Phase-Shift Keying (BPSK), which is often used in low-power sensor systems. Most importantly, we conducted realistic field measurements to study the effects of multipath fading and shadowing. Our results clearly show that BOC is perfectly suited for ultra-low power communication in forest environments.