Time reversal for source localization in urban environments considering the effects of Doppler shift

Time reversal can be used as a secure communication means between two terminals without knowing their locations. In this case, the time reversed signal will focus at the targeted terminal automatically. This same mechanism can also be used in the determination of the source location of a transmitted signal, especially in complex urban environments. The complex structure of streets, buildings, and other elements of an urban area are difficult to model and prove especially difficult for source detection. For this purpose, time reversal is a viable method which is well suited for the rich multipath domain provided by a complex urban setting. Time reversal has been employed in numerical methods, such as FDTD, for source localization. These methods are accurate and convenient for time reversal as they operate in the time domain. However, these methods are not well suited for simulation of the physically and electrically large sizes of urban areas. Ray tracing is a suitable method which can provide fast and accurate performance in modelling such environments.