Transmission focusing: A multi-antenna space hopping technique

Space hopping is a transmission scheme that emits wireless signals by rapidly switching transmit antennas according to the space hopping pattern. This paper proposes a transmission focusing based space hopping technique which aims at improving communication security by exploiting spatial resources sufficiently. More specifically, the legitimate user first transmits a training signal. Then the transmitter detects and processes the received signal and transmits the information bearing signal back. Thus, energy is focused on the legitimate user so that the signal-to-noise ratio of the legitimate user has an advantage over the eavesdropper. The risk of interception is reduced since there is no information exchange between the transmitter and the legitimate user. Rapidly switching antennas enhances the changing speed of the channel between the transmitter and the eavesdropper. Therefore it is hard for the eavesdropper to demodulate signals correctly. Simulation results are provided and analyzed to show the performance of the proposed scheme.