Research On Coverage Control And Data Transmission Technology In Wireless Sensor Networks

Wireless sensor network is playing an increasingly important role in the next generation Internet by virtue of its low cost, high self-organization and a wide range of applications. With the characteristics of multi-hop communication and many-to-one flow among sensors, the "energy hole" problem rises in the region near the sink node because of overloading.In this paper,In order to maximize network lifetime, the coverage control technology and the data transmission problem based on balanced-energy consumption in wireless sensor network are studied in depth.Coverage control is the primary issue to be solved in wireless sensor networks. According to the number of hops between sensors and the sink node, the target area is divided into several adjacent coronas. And then, the network model based on non-uniform node distribution is presented. By introducing the concept of equivalent sensing radius, the reachability condition of balancing energy depletion and eliminating the energy hole is analyzed theoretically. As a contribution, a centralized node distribution algorithm and a distributed node distribution algorithm are proposed respectively. Simulation results verify that the proposed algorithms can improve the coverage rate effectively, and outperform existing algorithms in terms of energy consumption. Since uniform node distribution can easily lead to the emergence of "energy hole" in wireless sensor networks, the network nodes are divided into sensing nodes and relay nodes so as to deal with uneven energy depletion. According to the concept of relay rings, the network model based on relay transmission is presented. Combining the reachability condition of energy balanced depletion, a novel relay node distribution and data forwarding strategy is proposed. By planning relay node density and deployment manner rationally, the process of data collection and transmission are separated to balance energy consumption in the whole network. Simulation results show that both sensing nodes and relay nodes can balance energy depletion at the end of network lifetime, thus the largest network lifetime is guaranteed. Data transmission is another problem to be solved in wireless sensor network. Considering the high degree of correlation among sensing data, the compressive sensing theory is introduced. In response to the sparse expression of original signal in a certain domain, a data transmission scheme based on compressive sensing is designed. By estimating the signal sparsity in advance, an improved OMP reconstruction algorithm is proposed. In hence, reconstructing the original signal accurately without knowing its sparsity is possible. Further, in response to the time variability of natural signal, a novel data collection algorithm on the basis of error feedback is proposed. Simulation results demonstrate that the proposed algorithms can effectively decrease the amount of sensing data forwarded by sensors, reduce the energy consumption and obtain a lower reconstruction error.