Unifying of frequency channel for spectrum sharing in wireless sensor networks with star topology

Wireless sensor networks (WSN) usually selects star type network topology because a lot of sensor nods access a fusion center (FC). WSN are distributed wireless communication system for highly adoption to various applications. Since each node chooses the frequency channel by its own rule, the frequency channel mismatch between each sensor and FC occurs. Therefore, the frequency channel synchronization technique is necessary. If we consider the spectrum sharing to the other system, it needs the robustness to the co-channel interference. This paper proposes the novel frequency channel synchronization based on sweeping carrier. The sweeping carrier achieves high robustness owing to coherent combining but consuming the time for charging energy. We show the effect of proposed technique by the experimental evaluation based on the universal software radio peripheral (USRP).