An Optimization Of Power Consumption For Wireless Video Sensor Networks

Wireless sensor networks consiste of a large number of wireless sensor nodes. Some kinds of information of the node's deployed area can be detected, sensed, and collected in real-time. This information is processed and sent out wirelessly. Wireless sensor networks has broad application prospects, such as, military investigation, environmental testing, industrial production and ect. Wireless video communication sensor networks is limited by energy supply and computational ability of each node. So the quality of video transmission and wireless sensor network lifetime should be considered together.This dissertation first summarized the research on energy-saving of wireless sensor networks, especially wireless video sensor networks, and introduced the image coding theory, concepts and relevant methods. On this basis, this dissertation analyzed non-energy-constrained general video transmission process and the corresponding technology, and intensively studied the Rate-Distortion model of video transmission and the quantitative relationship between distortion and coding performance. Then the energy consumption-related factors of coding process is analyzed, which indicated that encoding method based on motion estimation and compensation is suitable for wireless video sensor networks. To analyze, control, and optimize the rate-distortion behavior of the wireless video communication system, we developed a power-rate-distortion analysis framework under the condition of energy constraint. Using this model, the optimization of power consumption can be reached, while the distortion is permitted. An alternative optimization model is set up. The optimal coding quality and optimal distribution of the energy can be reached, while the node energy in certain circumstances.Based on the penalty function method, this dissertation also gives an algorithm to solve the optimization model, and programs a code of the algorithm. After this a specific optimization model with a set of parameters is solved, and the minimum expenditure of energy for the nodes under different condition of distortion is given. At the end of this dissertation, the work of the full text is summarized, and the direction of future work is pointed out.