Research On Modeling Of Interference And Estimation Of Spectral Hole Of Wireless Sensor Networks Baed On Time Reversal

Time reversal with its unique spatial and temporal focal ability has been proppsed to ensure the coexistence of wireless sensor networks. Based on time reversal, the radiation energy near the focal node will be focused at the focal node, which offers us a new a way to mitigate the interference among the sensors. What’s more, because of the focus of the energy, there exist some areas with spectrum hole near the focal node. Those areas may be utilized to ensure sensor nodes can work simutaneously with the same operating frequency. However, to obtain the interference level and the spectrum hole near the focal node, we need to find the mechanism for the focus of time reversal wave and then build a wireless channel model wihich can characterize the spatiotemporal focal ability of time reversal wave. Based on the proposed model, we can find a fast way to estimate spectrum hole near the focal node. My main work in this paper includes three parts.First, by study the focus mechanism of time reversal wave, build a statisitical channel model which can characterize the spatial and temporal focus property of time reversal wave. Give the method to extract the statistical paratmeters of the model. By adjusting the paratmetering in the model, discuss the spatial focus ability of TR waves in different situation, which offers a guidence about the system design, the environment setting, and the node distribution of time reversal based wireless sensor networks.Second, based on the new satatistical channel model, we proposed a method to quickly estimate the spectrum hole near the focal node. This method gives the estimation of the spectral hole near the focal node, which saves the usage of sensing node and time resourse.Finally, based on time reversal technique, we proposed a phase disturb algorithm to decrease the peak interference among the nodes of the wireless sensor networks.