Some array processing techniques based on transmit beam forming provide some degree of secure communication along the angular domain by focusing the signal energy towards the intended node while minimizing the signal for the eavesdroppers located along other angles. However, these approaches cannot provide secure communication when the illegitimate receiver (Rx) stands along the same angle with the intended Rx. Also, with array processing based on only the angular location of the intended Rx in the existing schemes, independent channel responses between transmitter (Tx) antennas are not considered, and this makes the techniques ineffective in the practical fading channel scenarios. USF inventors have developed an advanced novel transmission scheme based on channel pre-coding and adaptive antenna subset selection in MISO wireless systems for highly secure and resilient communication links between the legitimate transmitter and receiver. In addition, by combining the channel hopping scheme with the frequency hopping-based pre-coding, they have achieved resilience against jamming attacks.
Example of a Communication Environment with the Transmitter, Intended Receiver and an Eavesdropper