Time Reversal with Single Antenna Systems in Indoor Multipath Environments
The time reversal (TR) technique has been well investigated for sound wave applications. Recently, the same idea has been extended to telecommunications and the electromagnetic waves. Lerosey, et al., reported that the spatial focusing and time compression were experimentally achieved in a reverberant chamber with a one transmit and one receive antenna system (1 x1 antenna system). TR has also been employed in other areas of research, e.g., the imaging of targets in complex environments6,7 and microwave nulling
This research focuses on the characterization of TR with single antenna systems. To achieve energy focusing using a single antenna system, wideband signals and multipath environments are required. We examine the TR property in indoor multipath environments which have typical propagation features such as the waveguide effect of hallways, multiple reflection and transmission of slab walls, diffraction from edges (especially metal edges), and scattering from various small structures. The signal waveform is a wideband monocycle. The two-dimensional finite-difference time-domain (FDTD) method is employed for the simulation of the wave propagation in an indoor environment. The effect of furniture and other scattering objects in the region of interest is investigated. To quantitatively characterize the spatial energy focusing, a spatial energy focusing factor (SEF) is defined. It is found that spatial energy focusing can be achieved in the indoor environment and that the scatterers can significantly improve the spatial energy focusing.
KeywordsIndoor Environment Time Reversal FDTD Method Wideband Signal Multipath Environment
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- 8.A. G. Cepni, and D. D. Stancil, Single antenna microwave nulling using time-reversal techniques, Proceedings of IEEE IMS’05, 1723-1726 (2005).Google Scholar