Wireless Cloaking System Based on Time-Reversal Multipath Propagation Effects

In this communication, we present a new method of encoding /decoding information contained in a wave packet using multipath effect. A signal is mixed with an auxiliary signal and sent into an enclosed cavity. The strongly distorted signal transmitted through the cavity is then sent to a receiver, where it is time reversed and sent to a second enclosed metallic cavity that is strictly identical to the first one. As a result, the waveform of the initial signal is reconstructed at a point of the second cavity that is equivalent to the point of the first cavity due to the spatial and temporal focusing. Using the mechanism, secure wireless data transmission is carried out. Finally, the impact of the size of the cavity on intersymbol interference and the frequency dispersion caused by frequency selective fading are discussed. Such a communication system ensures a high level of security.