Interference mitigation study for low energy critical infrastructure monitoring applications

Low energy critical infrastructure monitoring (LECIM) applications are rapidly increasing, whose common requirements derived from the type of communications performed include reliable data transfer, energy efficiency, long deployment lifetime, and low infrastructure cost. A low rate wireless personal area network (WPAN) can help control and manage the operations of such applications. To facilitate point to multi-points communication for LECIM devices, the IEEE 802.15.4k task group is formed as an amendment to IEEE 802.15.4. In this paper, we first review the main activities of TG15.4k with the updated status and the structure of LECIM networks. Then, after analyzing the interference issues in the LECIM system, especially for the direct-sequence spreading spectrum (DSSS) physical layer, we propose the interference mitigation schemes by combining time division multiplexing (TDM), frequency division multiplexing (FDM) and code division multiplexing (CDM). Furthermore, to mitigate the homogeneous interference more effectively, the orthogonal variable spreading factor (OVSF) codes based CDM are analyzed. Monte Carlo simulation results show that the proposed interference mitigation schemes has robustness against the interference under the LECIM multi cluster environments.