Virtual MISO Based Energy-Efficient Broadcasting in Clustered Wireless Sensor Networks

Energy efficiency is of great importance in wireless sensor networks, where each node is typically powered by battery with limited energy supply. In this case, cooperative broadcasting plays a significant role in saving transmission power consumption by introducing the accumulation of signal energy and cooperative transmission. In this paper, we consider a clustered wireless sensor network (WSN) where a virtual MISO based energy-efficient broadcasting scheme is investigated with centralized and distributed algorithms. Specifically, sensors within each cluster relay message to nearby clusters via cooperative transmissions in conjunction with proper Space Time Block Codes (STBCs) till the entire network is connected. Further, to minimize the total transmission power, a centralized algorithm is presented with only one cluster head reached at each iteration. Also, to facilitate implementation, two distributed algorithms are introduced based on inter-cluster cooperative transmission with knowledge of intra-cluster channel state information (CSI). There performance analyses show that our scheme is more energy-efficient than other counterparts.