Multi-carrier-Based Positional Modulation Design

With DM technology, the signal transmitted by the transmitter can be received in the desired direction/directions correctly, while in other directions, the eavesdropper cannot obtain the information. However, if eavesdroppers aligned with the desired direction/directions, the DM design will cause a problem as the received signals by eavesdroppers are similar to the one received by the desired user. In this paper, positional modulation (PM) as an extension of directional modulation technology is proposed, which overcomes the shortcoming of DM technology by finding the appropriate weight vector to make a given modulation pattern at certain desired positions but scrambles the patterns at other directions. The advantage of the proposed multi-carrier-based design is that multiple signals over multiple frequencies can be achieved at receivers simultaneously.