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The dynamic coverage algorithm is a distributed algorithm in the area of random deployment. This algorithm extends the networks' survival time through alternating nodes' two states of sleeping and activity. During the process of this algorithm, “lock” mechanism is used to avoid infinite iteration of distributed algorithms and deadlock phenomenon. Nodes' residual energy is also considered as an important tool to balance the energy consumption of the network. The experimental simulation results of this algorithm show that, on the condition of keeping good quality of coverage, our algorithm requires less sensor nodes to support the network and more sensor nodes to live longer, and consequently prolonged survival time of the network. [ABSTRACT FROM PUBLISHER]

A robust modulation recognition scheme is proposed to identify practical QAM signals, which suffer from various unknown effects including multipath propagation, pulse shaping, time delay, and phase shift. Relying on blind signal processing techniques, the proposed scheme consists of two steps: front-end signal processing followed by modulation classification. At the first step, a fractionally-spaced blind equalizer is applied to accomplish equalization and time synchronization. Phase shift is then estimated and corrected. As required, signal-to-noise ratio is also estimated. At the second step, modulation formats are classified via characteristic function. Simulation results are provided to show the performance of the proposed scheme. [ABSTRACT FROM PUBLISHER]

Clustering method can increase the wireless sensor network scalability and life. Data is transmitted to the base station by multi-hop. These nodes near the base station may be failure early because of excessive energy consumption. That will lead to the network energy consumption unbalanced. This paper proposes a mixed non-uniform clustering (MNUC) algorithm. It draws on the calculation plat routing method of redundant nodes, and creative plane routing and hierarchical routing will combine. We will take distance and energy in, with limited clustering radius to solve the problem of network load imbalance caused by the multi-hop transmission. Finally, data will be transferred through the minimum spanning tree to the base station, further saving energy and extending network lifetime. Simulation results show that the routing protocol effectively balance the energy consumption of cluster head, and significantly prolong the survival time of the network. [ABSTRACT FROM PUBLISHER]