Enhanced sensitivity of collision detection by carrier frequency offset switching in physical wireless parameter conversion sensor networks

Abstract

This study proposes a novel method for determining the number of simultaneously accessing sensors in physical wireless parameter conversion sensor networks (PhyC-SN), which can collect sensor information from numerous sensors simultaneously, using phase variation due to frequency offset as an identifier. However, the identification accuracy deteriorates when the frequency offsets of the simultaneously accessed sensors are close to each other. In the proposed method, the transmitted signal is divided by time and the frequency offset is switched for each signal transmission. Computer simulations reveal that the identification accuracy of collision detection improves and an appropriate number of frequency switches exist.