Fig. 6From: Directional modulation techniques for secure wireless communication: a comprehensive surveyIn this figure, three broad categories of optimization approaches for increasing the physical layer security of directional modulation techniques available in the literature are summarized. The optimization goal from communications’ paradigm is to increase symbol error rate in the direction of eavesdropper. Information-theoretic optimization maximizes the channel secrecy in the undesired directions. Finally, cryptographic viewpoint proposes physical layer randomness driven synthesis of directional modulationBack to article page