Directional modulation techniques for secure wireless communication: a comprehensive survey

Abstract

Directional Modulation (DM) techniques provide wireless communication security against passive eavesdropping by means of specific physical layer characteristics. The original symbol constellations are transmitted along pre-specified spatial direction of legitimate users, while phase-amplitude distorted symbols are transmitted along the undesired directions of eavesdropper. In this paper, a comprehensive review of DM techniques and the most recent developments in this area are discussed. An analysis from three independent Physical Layer Security (PLS) viewpoints; communications, information-theoretic and cryptographic perspective is presented. Different performance metrics in literature are compared and the need for unified PLS approach is emphasized. As DM techniques constitute a relatively new class of PLS, there is no systematic organization of these techniques so far. This paper presents a classification framework for DM comprising of two main categories; angular (1D) and range-angular (2D) techniques. The former secures data along angular direction of physical space, while the latter provides security within certain range (distance) from the transmitter along desired angular direction. Further sub-categorization is based on the under-lying physical layer parameters exploited to achieve security, i.e. space, time, frequency, phase and polarization. The proposed framework is generic, flexible and extend-able to future research. In the end, limitations of existing techniques are pointed out and research directions are suggested.

Multi-User Directional Modulation with Reconfigurable Holographic Surfaces

“…The authors also proposed M -ary PSK by the same antenna switching mechanism using M -element array, where direction-dependent amplitude changes are achieved by appropriately selecting combinations of antennas. Since that work, the concept of DM has been investigated intensively in different aspects [9]. As the number of studies related to large antenna arrays in communication systems increases, the DM concept becomes an important research area [10].…”