Direct Position Determination with Single Sensor Based on Signal Periodicity

Due to practical limitations on size and cost, aerial vehicles generally cannot equip complicated sensors to form sensor array for target localization. In this paper, we investigate the direct position determination (DPD) of stationary source via single moving sensor. First, we analyze artificial signal structure and construct the DPD model with the frame periodicity of artificial signal. The model incorporates Doppler information extracted from both transformation frames and adjacent samples into target localization. Secondly, we consider the effect of oscillator instability and present an iterative solution for joint estimation of target location and phase noise caused by oscillator imperfection. The proposed technique fully exploits periodic structure of artificial wireless signal, which leads to significant enhancement in localization performance. Both theoretical analysis and simulations are presented to confirm its effectiveness.

RPLL - Rendezvous protocol for long-living sensor node

Sensor nodes (SNs), as constituents of wireless sensor network (WSN), are battery-powered not rechargeable devices and have limited amount of energy available. Since the lifetime of SNs is a crucial parameter for energy-efficient WSN design, it is essential to extend their lifetimes as much as possible. Here we propose a rendezvous scheme called Rendezvous Protocol for Long-Living SN, RPLL. This scheme is based on implementation of a duty-cycling technique. For each SN within WSN a unique identification number (ID) is allocated, thanks to which a collision problem is effectively remedied. The RPLL provides an on time wake-up of SNs in a fully decentralized way and fast detection of new appended SNs. Taking into account the WSN and SN working parameters, such as beacon time, beacon period, number of active SNs, and quartz oscillator instability, by using the proposed method, a WSN designer can determine the maximal lifetime of a SN, i.e. achieve optimal energy consumption.