Enhanced Multi-trilateration Method to Mitigate Shadow Fading for ROA-based Indoor Sensor Localization

Sensor localization is difficult in indoor environments because of the multipath fading and shadow fading caused by obstacles [1]. Multipath fading and shadow fading cause large localization errors that make the sensor node fail in the sensor localization process. This paper highlights the indoor sensor localization concept and proposes a ROA (Received signal strength Of Arrival)-based sensor localization scheme. The proposed scheme called RERR (Range Expansion and Range Reduction) can mitigate the above-mentioned problems for indoor environments. The RERR-based sensor nodes virtually expand or reduce the measured range to succeed in localization regardless of the effects of multipath fading and shadow fading over communicating sensor nodes. The simulation results verified the effectiveness of the proposed scheme, showing small RMS errors and a large number of sensor nodes succeeding in the localization process.